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Showing papers in "Vaccines in 2022"


Journal ArticleDOI
01 Jan 2022-Vaccines
TL;DR: The analysis shows that there are global variations in vaccine acceptance among different populations, and the reasons behind vaccine hesitancy and acceptance were similar across the board.
Abstract: COVID-19 vaccines have met varying levels of acceptance and hesitancy in different parts of the world, which has implications for eliminating the COVID-19 pandemic. The aim of this systematic review is to examine how and why the rates of COVID-19 vaccine acceptance and hesitancy differ across countries and continents. PubMed, Web of Science, IEEE Xplore and Science Direct were searched between 1 January 2020 and 31 July 2021 using keywords such as “COVID-19 vaccine acceptance”. 81 peer-reviewed publications were found to be eligible for review. The analysis shows that there are global variations in vaccine acceptance among different populations. The vaccine-acceptance rates were the highest amongst adults in Ecuador (97%), Malaysia (94.3%) and Indonesia (93.3%) and the lowest amongst adults in Lebanon (21.0%). The general healthcare workers (HCWs) in China (86.20%) and nurses in Italy (91.50%) had the highest acceptance rates, whereas HCWs in the Democratic Republic of Congo had the lowest acceptance (27.70%). A nonparametric one-way ANOVA showed that the differences in vaccine-acceptance rates were statistically significant (H (49) = 75.302, p = 0.009*) between the analyzed countries. However, the reasons behind vaccine hesitancy and acceptance were similar across the board. Low vaccine acceptance was associated with low levels of education and awareness, and inefficient government efforts and initiatives. Furthermore, poor influenza-vaccination history, as well as conspiracy theories relating to infertility and misinformation about the COVID-19 vaccine on social media also resulted in vaccine hesitancy. Strategies to address these concerns may increase global COVID-19 vaccine acceptance and accelerate our efforts to eliminate this pandemic.

80 citations


Journal ArticleDOI
01 Mar 2022-Vaccines
TL;DR: Being male and perceiving risk of COVID-19 infection were predictors for willingness to accept the vaccine and increasing vaccine acceptance rates in the global south should be prioritized to advance global vaccination coverage.
Abstract: Widespread vaccination against COVID-19 is critical for controlling the pandemic. Despite the development of safe and efficacious vaccinations, low-and lower-middle income countries (LMICs) continue to encounter barriers to care owing to inequitable access and vaccine apprehension. This study aimed to summarize the available data on COVID-19 vaccine acceptance rates and factors associated with acceptance in LMICs. A comprehensive search was performed in PubMed, Scopus, and Web of Science from inception through August 2021. Quality assessments of the included studies were carried out using the eight-item Joanna Briggs Institute Critical Appraisal tool for cross-sectional studies. We performed a meta-analysis to estimate pooled acceptance rates with 95% confidence intervals (CI). A total of 36 studies met the inclusion criteria and were included in the review. A total of 83,867 respondents from 33 countries were studied. Most of the studies were conducted in India (n = 9), Egypt (n = 6), Bangladesh (n = 4), or Nigeria (n = 4). The pooled-effect size of the COVID-19 vaccine acceptance rate was 58.5% (95% CI: 46.9, 69.7, I2 = 100%, 33 studies) and the pooled vaccine hesitancy rate was 38.2% (95% CI: 27.2–49.7, I2 = 100%, 32 studies). In country-specific sub-group analyses, India showed the highest rates of vaccine acceptancy (76.7%, 95% CI: 65.8–84.9%, I2 = 98%), while Egypt showed the lowest rates of vaccine acceptancy (42.6%, 95% CI: 16.6–73.5%, I2 = 98%). Being male and perceiving risk of COVID-19 infection were predictors for willingness to accept the vaccine. Increasing vaccine acceptance rates in the global south should be prioritized to advance global vaccination coverage.

74 citations


Journal ArticleDOI
01 Jun 2022-Vaccines
TL;DR: The results show that HBM is useful in predicting COVID-19 vaccine hesitancy and a positive association was found between perceived barriers and vaccine Hesitancy.
Abstract: This study systematically analyzes the research that used the Health Belief Model (HBM) as a theoretical basis to examine the influence of HBM constructs on COVID-19 vaccine hesitancy. Following PRISMA guidelines, PubMed, Web of Science, Google Scholar, and Scopus were searched for quantitative studies. Sixteen studies with 30,242 participants met inclusion criteria. The prevalence of COVID-19 vaccine hesitancy was 33.23% (95% CI 24.71–41.39%). Perceived barriers and perceived benefits were the most common HBM constructs that were significantly associated with vaccine hesitancy. While perceived benefits was inversely associated, a positive association was found between perceived barriers and vaccine hesitancy. Other HBM constructs that were frequently examined and inversely associated were perceived susceptibility, cues to action, perceived severity, and self-efficacy. The most common HBM modifying factor that was directly associated with COVID-19 vaccine hesitancy was gender, followed by education, age, geographical locations, occupation, income, employment, marital status, race, and ethnicity; however, a few studies report inconsistent results. Other modifying variables that influenced vaccine hesitancy were knowledge of COVID-19, prior diagnosis of COVID-19, history of flu vaccination, religion, nationality, and political affiliation. The results show that HBM is useful in predicting COVID-19 vaccine hesitancy.

56 citations


Journal ArticleDOI
24 Jan 2022-Vaccines
TL;DR: In the determinant assessment, the age ofParents and guardians, access to scientific information and recommendations, routine and influenza vaccination behavior, and the willingness of parents and guardians to vaccinate themselves were potentially significant predictors of the vaccination willingness.
Abstract: COVID-19 vaccination for children is crucial to achieve herd immunity. This is the first systematic review and meta-analysis to estimate parents’ and guardians’ willingness to vaccinate their children against COVID-19 and identify the determinants of vaccination intention. Systematic research was performed on the two databases (PubMed and EMBASE) from inception to 6 November 2021. Acceptance rates were pooled by use of a random-effects model and all predictors of vaccine acceptance were identified according to the health belief model (HBM) framework. This analysis was registered with PROSPERO (CRD42021292326) and reported in compliance with the PRISMA guidelines. Of 452 identified records, 29 eligible studies were included (N = 68,327 participants). The estimated worldwide vaccination acceptance rate was 61.40% (95% CI: 53.56–68.69%, I2 = 99.3%), ranging from 21.6% to 91.4% across countries and regions. In the determinant assessment, the age of parents and guardians, access to scientific information and recommendations, routine and influenza vaccination behavior, and the willingness of parents and guardians to vaccinate themselves were potentially significant predictors of the vaccination willingness. Given the limited quality and quantity of included articles, future studies with a rigorous design will be necessary for the confirmation of our findings.

55 citations


Journal ArticleDOI
01 Jun 2022-Vaccines
TL;DR: Several interventions to encourage vaccination have been studied, including education programs and non-monetary incentives with the most effective studies using a combination of methods.
Abstract: The COVID-19 pandemic and its associated vaccine have highlighted vaccine hesitancy among healthcare workers (HCWs). Vaccine hesitancy among this group existed prior to the pandemic and particularly centered around influenza vaccination. Being a physician, having more advanced education, and previous vaccination habits are frequently associated with vaccine acceptance. The relationship between age and caring for patients on COVID-19 vaccination is unclear, with studies providing opposing results. Reasons for hesitancy include concerns about safety and efficacy, mistrust of government and institutions, waiting for more data, and feeling that personal rights are being infringed upon. Many of these reasons reflect previous attitudes about influenza vaccination as well as political beliefs and views of personal autonomy. Finally, several interventions to encourage vaccination have been studied, including education programs and non-monetary incentives with the most effective studies using a combination of methods.

53 citations


Journal ArticleDOI
19 Jan 2022-Vaccines
TL;DR: Females had a significantly higher perceived risk of getting the SARS-CoV-2 infection, whereas those not-having a cohabitant were less worried and those who did not need information would be willing to get the booster dose.
Abstract: This cross-sectional study, conducted in Naples (Italy) between 16 November and 6 December 2021, explored the willingness to receive the booster dose of the COVID-19 vaccine among a random sample selected from the list of those who had completed a primary vaccination series at the immunization center of a teaching hospital in Naples and the associated factors. Females had a significantly higher perceived risk of getting the SARS-CoV-2 infection, whereas those not-having a cohabitant were less worried. 85.7% were willing to receive the booster dose. Those older respondents who perceived a better health status after the primary vaccination series, who have friends/family members who were diagnosed with COVID-19, who had received information from official government organizations, and those who did not need information would be willing to get the booster dose. 24.7% was hesitant with a Vaccine Hesitancy Scale (VHS) score ≥ 25. Respondents who self-rated a lower health status after the primary vaccination series, who did not have friends/family members who were diagnosed with COVID-19, who had not received information from official government organizations, and who needed information were hesitant. Information and communication regarding the benefits and efficacy of the booster dose are needed in order to control the pandemic.

52 citations


Journal ArticleDOI
06 Jan 2022-Vaccines
TL;DR: In this paper , the authors evaluated the booster effect of different platforms of vaccines, including inactivated vaccine (BBIBP), viral vector vaccine (AZD122), and mRNA vaccine(BNT162b2), in healthy adults who received the full dose of inactivated vaccines and found that the booster dose was safe with no serious adverse events.
Abstract: The coronavirus disease 2019 (COVID-19) pandemic has become a severe healthcare problem worldwide since the first outbreak in late December 2019. Currently, the COVID-19 vaccine has been used in many countries, but it is still unable to control the spread of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection, despite patients receiving full vaccination doses. Therefore, we aimed to appraise the booster effect of the different platforms of vaccines, including inactivated vaccine (BBIBP), viral vector vaccine (AZD122), and mRNA vaccine (BNT162b2), in healthy adults who received the full dose of inactivated vaccine (CoronaVac). The booster dose was safe with no serious adverse events. Moreover, the immunogenicity indicated that the booster dose with viral vector and mRNA vaccine achieved a significant proportion of Ig anti-receptor binding domain (RBD), IgG anti-RBD, and IgA anti-S1 booster response. In contrast, inactivated vaccine achieved a lower booster response than others. Consequently, the neutralization activity of vaccinated serum had a high inhibition of over 90% against SARS-CoV-2 wild-type and their variants (B.1.1.7-alpha, B.1.351-beta, and B.1.617.2-delta). In addition, IgG anti-nucleocapsid was observed only among the group that received the BBIBP booster. Our study found a significant increase in levels of IFN-ɣ secreting T-cell response after the additional viral vector or mRNA booster vaccination. This study showed that administration with either viral vector (AZD1222) or mRNA (BNT162b2) boosters in individuals with a history of two doses of inactivated vaccine (CoronaVac) obtained great immunogenicity with acceptable adverse events.

49 citations


Journal ArticleDOI
01 Apr 2022-Vaccines
TL;DR: M Males, older individuals, those with chronic comorbidities or a history of COVID-19 infection, non-healthcare workers, and those with low educational levels were associated with significantly higher odds for booster acceptance, while belief that booster doses were necessary and efficient, disagreeing with the notion that primer doses were not sufficient, experts’ recommendations, and the desire to travel abroad were significantly associated with higher odds of booster acceptance.
Abstract: Due to the emergence of various highly contagious variants of SARS-CoV-2, vaccine boosters were adopted as a complementary strategy in different countries. This strategy has, however, posed another challenge for the national authorities to convince their population to receive the booster after the first challenge of COVID-19 primer dose vaccines. This study was conducted to determine COVID-19 vaccine booster acceptance and its associated factors in the general population in Algeria. Using social media platforms, an online self-administered questionnaire was distributed between 28 January and 5 March 2022 for all Algerian citizens who received COVID-19 vaccines. Overall, 787 respondents were included in this study. Among them, 51.6%, 25%, and 23.8% accepted, rejected, or were hesitant about the COVID-19 vaccine booster, respectively. However, only 13.2% declared receiving the booster dose. Additionally, while 58.2% of the respondents declared being relieved after primer vaccination, 11.4% among them declared that they regretted being vaccinated. The most common reasons for acceptance were experts’ recommendations (24.6%) and the belief that COVID-19 vaccine boosters were necessary and efficient, while rejection was mainly due to the belief that primer doses are sufficient (15.5%), or that vaccination in general is inefficient (8%). Males, older individuals, those with chronic comorbidities or a history of COVID-19 infection, non-healthcare workers, and those with low educational levels were associated with significantly higher odds for booster acceptance. Moreover, belief that booster doses were necessary and efficient, disagreeing with the notion that primer doses were not sufficient, experts’ recommendations, and the desire to travel abroad were significantly associated with higher odds of COVID-19 vaccine booster acceptance.

44 citations


Journal ArticleDOI
01 Feb 2022-Vaccines
TL;DR: This rapid systematic review indicates that active smoking negatively impacts humoral response to COVID-19 vaccines, although the pathophysiologic mechanisms for this association have not been entirely suggested.
Abstract: While the role of active smoking on response to vaccines is yet to be fully understood, some real-world studies have outlined a possible link between smoking and humoral response to COVID-19 vaccines. Thus, the present rapid systematic review aimed at summarizing the current epidemiological evidence on this association. Following PRISMA and WHO guidelines on rapid systematic reviews, we systematically reviewed published literature on this topic and discussed the findings according to the aim of analysing smoking and its impact on humoral response to COVID-19 postvaccination antibody titres. The search strategy yielded a total of 23 articles. The sample size amongst the studies ranged between 74 and 3475 participants (median, 360), with the proportion of smokers being between 4.2% and 40.8% (median, 26.0%). The studies included in this review analysis investigated the dynamics of antibody response to different type of COVID-19 vaccines. In 17 out of 23 studies, current smokers showed much lower antibody titres or more rapid lowering of the vaccine-induced IgG compared with nonsmokers. This rapid systematic review indicates that active smoking negatively impacts humoral response to COVID-19 vaccines, although the pathophysiologic mechanisms for this association have not been entirely suggested. The results advocate targeted policies to promote tailored health promotion initiatives, which can increase risk perception and ensure appropriate protection measures to be taken to avoid the health consequences of COVID-19 in smokers.

44 citations


Journal ArticleDOI
01 Feb 2022-Vaccines
TL;DR: The consistent excess in adverse events among females for the mRNA COVID-19 vaccine indicates the need to assess and report vaccine adverse events by gender and should be taken into account when determining dosing schedules.
Abstract: Background: The adverse events reported from the COVID-19 mRNA vaccines have varied from very mild, such as pain near the vaccination site, to more severe, with occasional anaphylaxis. Details of age-specific gender differences for the adverse effects are not well documented. Methods: Age and gender disaggregated data on reports of adverse events following two or three doses of the Pfizer-BioNTech COVID-19 vaccine were obtained from four cross-sectional studies. The first was from reports submitted to the Israel Ministry of Health national adverse events database (for ages 16 and above). The second was from a national cross-sectional survey based on an internet panel (for ages 30 and above), and the third and fourth were from cross-sectional surveys among employees of a large company (for ages 20–65) using links to a self-completed questionnaire. Results: In all studies, the risks of adverse events were higher following the second dose and consistently higher in females at all ages. The increased risk among females at all ages included local events such as pain at the injection site, systemic events such as fever, and sensory events such as paresthesia in the hands and face. For the combined adverse reactions, for the panel survey the female-to-male risk ratios (RRs) were 1.89 for the first vaccine dose and 1.82 for the second dose. In the cross-sectional workplace studies, the female-to-male RRs for the first, second and third doses exceeded 3.0 for adverse events, such as shivering, muscle pain, fatigue and headaches. Conclusions: The consistent excess in adverse events among females for the mRNA COVID-19 vaccine indicates the need to assess and report vaccine adverse events by gender. Gender differences in adverse events should be taken into account when determining dosing schedules.

43 citations


Journal ArticleDOI
09 Mar 2022-Vaccines
TL;DR: The most frequently mentioned reasons for participants' reluctance to get the COVID-19 vaccine booster dose were "The benefits of booster dose have not been scientifically proven" (39.8%), followed by "I took the last dose a short time ago, and there will be no need to take the booster dose for at least a year" (24.6%), and "I was infected with COVID19; thus, I do not require the booster shot" was the least reported reason (13.1%) as discussed by the authors .
Abstract: SARS-CoV-2 (COVID-19) vaccines are critical for containing serious infections. However, as COVID-19 evolves toward more transmissible varieties and serum antibody levels in vaccinated persons steadily decline over time, the likelihood of breakthrough infections increases. This is a cross-sectional study based on an online questionnaire for Jordanian adults (n = 915) to determine how individuals who have finished the current vaccination regimen feel about a prospective COVID-19 booster shot and what factors might influence their decision. Almost half of the participants (44.6%) intended to get the booster dose of the COVID-19 vaccine. The most frequently mentioned reasons for participants' reluctance to get the COVID-19 vaccine booster dose were "The benefits of booster dose have not been scientifically proven" (39.8%), followed by "I took the last dose a short time ago, and there will be no need to take the booster dose for at least a year" (24.6%). In turn, "I was infected with COVID-19; thus, I do not require the booster dose" was the least reported reason (13.1%). These findings highlight the considerable hesitancy toward COVID-19 booster immunization among Jordanians, as well as the variables associated with vaccine hesitancy and the most frequently mentioned reasons for hesitancy, which will aid in creating excellent campaigns regarding booster doses.

Journal ArticleDOI
21 Apr 2022-Vaccines
TL;DR: The survey suggests COVID-19 vaccination may improve long COVID patients, on average, and larger improvements in symptom severity scores were seen in those receiving the mRNA vaccines compared to adenoviral vector vaccines.
Abstract: Long COVID is a multi-system syndrome following SARS-CoV-2 infection with persistent symptoms of at least 4 weeks, and frequently for several months. It has been suggested that there may be an autoimmune component. There has been an understandable caution amongst some people experiencing long COVID that, by boosting their immune response, a COVID vaccine may exacerbate their symptoms. We aimed to survey people living with long COVID, evaluating the impact of their first COVID vaccination on their symptoms. Methods: Patients with long COVID were invited to complete a web-based questionnaire through postings on social media and direct mailing from support groups. Basic demographics, range and severity of long COVID symptoms, before and after their vaccine, were surveyed. Results: 900 people participated in the questionnaire, of whom 45 had pre-existing myalgic encephalomyelitis or chronic fatigue syndrome (ME/CFS) but no evidence of COVID infection, and a further 43 did not complete the survey in full. The demographics and symptomology of the remaining 812 people were similar to those recorded by the UK Office of National Statistics. Following vaccination, 57.9% of participants reported improvements in symptoms, 17.9% reported deterioration and the remainder no change. There was considerable individual variation in responses. Larger improvements in symptom severity scores were seen in those receiving the mRNA vaccines compared to adenoviral vector vaccines. Conclusions: Our survey suggests COVID-19 vaccination may improve long COVID patients, on average. The observational nature of the survey limits drawing direct causal inference, but requires validation with a randomised controlled trial.

Journal ArticleDOI
26 Mar 2022-Vaccines
TL;DR: The efficacy of the COVID-19 vaccine and concerns about adverse reactions had a significant impact on behavior regarding the third vaccination, and a rapid increase in the booster dose rate is needed to control the pandemic.
Abstract: This was a retrospective cohort study, which aimed to investigate the factors associated with hesitancy to receive a third dose of a coronavirus disease 2019 (COVID-19) vaccine. A paper-based questionnaire survey was administered to all participants. This study included participants who provided answers in the questionnaire about whether they had an intent to receive a third dose of a vaccine. Data on sex, age, area of residence, adverse reactions after the second vaccination, whether the third vaccination was desired, and reasons to accept or hesitate over the booster vaccination were retrieved. Among the 2439 participants, with a mean (±SD) age of 52.6 ± 18.9 years, and a median IgG-S antibody titer of 324.9 (AU/mL), 97.9% of participants indicated their intent to accept a third vaccination dose. The logistic regression revealed that participants of a younger age (OR = 0.98; 95% CI: 0.96–1.00) and with a higher antibody level (OR = 2.52; 95% CI: 1.27–4.99) were positively associated with hesitancy over the third vaccine. The efficacy of the COVID-19 vaccine and concerns about adverse reactions had a significant impact on behavior regarding the third vaccination. A rapid increase in the booster dose rate is needed to control the pandemic, and specific approaches should be taken with these groups that are likely to hesitate over the third vaccine, subsequently increasing booster contact rate.

Journal ArticleDOI
01 Jan 2022-Vaccines
TL;DR: Overall, residents in China showed a high willingness to accept the third dose of COVID-19 vaccines, which can help vaccine manufacturers in China to manage the vaccine production and distribution for the huge domestic and international vaccine demand.
Abstract: COVID-19 infections are returning to many countries because of the emergence of variants or declining antibody levels provided by vaccines. An additional dose of vaccination is recommended to be a considerable supplementary intervention. We aim to explore public acceptance of the third dose of the COVID-19 vaccine and related influencing factors in China. This nationwide cross-sectional study was conducted in the general population among 31 provinces in November, 2021. We collected information on basic characteristics, vaccination knowledge and attitudes, and vaccine-related health beliefs of the participants. Univariable and multivariable logistic regression models were used to assess factors associated with the acceptance of a third COVID-19 vaccine. A total of 93.7% (95% CI: 92.9–94.6%) of 3119 Chinese residents were willing to receive a third dose of the COVID-19 vaccine. Individuals with low level of perceived susceptibility, perceived benefit, cues to action cues, and high level of perceived barriers, old age, low educational level, low monthly household income, and low knowledge score on COVID-19 were less likely to have the acceptance of a third dose of COVID-19 (all p < 0.05). In the multivariable logistic regression model, acceptance of the third dose of COVID-19 vaccine was mainly related to previous vaccination history [Sinopharm BBIP (aOR = 6.55, 95% CI 3.30–12.98), Sinovac (aOR = 5.22, 95% CI:2.72–10.02), Convidecia (aOR = 5.80, 95% CI: 2.04–16.48)], high level of perceived susceptibility (aOR = 2.48, 95% CI: 1.48–4.31) and high level of action cues (aOR = 23.66, 95% CI: 9.97–56.23). Overall, residents in China showed a high willingness to accept the third dose of COVID-19 vaccines, which can help vaccine manufacturers in China to manage the vaccine production and distribution for the huge domestic and international vaccine demand. Relevant institutions could increase people’s willingness to booster shots by increasing initial COVID-19 vaccination rates, public’s perception of COVID-19 susceptibility and cues to action through various strategies and channels. Meanwhile, it also has certain reference significance for other countries to formulate vaccine promotion strategies.

Journal ArticleDOI
26 Feb 2022-Vaccines
TL;DR: This short communication tries to critically discuss the research work findings around booster dose strategy for omicron endemics in communities where people were previously infected with SARS-CoV-2 and are now being vaccinated.
Abstract: The Omicron variant of SARS-CoV-2 is emerging in communities where people were previously infected with SARS-CoV-2 and are now being vaccinated, or where many people have received two or three coronavirus vaccination doses. More than 130 countries around the globe have implemented booster dose programs for tackling omicron endemics. Despite early findings shows that booster doses may improve omicron protection, more research is needed to establish vaccination efficacy. This short communication tries to critically discuss the research work findings around booster dose strategy for omicron endemics.

Journal ArticleDOI
01 Feb 2022-Vaccines
TL;DR: This comprehensive review one-year into vaccination efforts against COVID-19 is meant to furnish sound understanding for ophthalmologists and primary care physicians based on the existing body of clinical data.
Abstract: Vaccination efforts as a mitigation strategy in the corona virus disease 2019 (COVID-19) pandemic are fully underway. A vital component of understanding the optimal clinical use of these vaccines is a thorough investigation of adverse events following vaccination. To date, some limited reports and reviews have discussed ocular adverse events following COVID-19 vaccination, but a systematic review detailing these reports with manifestations and clinical courses as well as proposed mechanisms has yet to be published. This comprehensive review one-year into vaccination efforts against COVID-19 is meant to furnish sound understanding for ophthalmologists and primary care physicians based on the existing body of clinical data. We discuss manifestations categorized into one of the following: eyelid, orbit, uveitis, retina, vascular, neuro-ophthalmology, ocular motility disorders, and other.

Journal ArticleDOI
01 Mar 2022-Vaccines
TL;DR: New policies and educational programs regarding COVID-19 vaccination for children with chronic conditions are needed to reduce hesitancy and increase vaccination uptake.
Abstract: COVID-19 vaccination has been extended to include children aged 5–11 years. This cross-sectional survey evaluated parental COVID-19 vaccine willingness and hesitancy, and associated factors, for their children aged 5–11 years with chronic conditions. A telephone survey was conducted from 14 December 2021 to 4 January 2022. The questionnaire assessed participants’ socio-demographic and health-related information, attitudes towards COVID-19 infection, hesitancy, by using the PACV-5 (Parent Attitudes About Childhood Vaccines Survey Tool), and sources of information. A total of 430 answers were collected anonymously. Respondents with no cohabitant who had been infected by SARS-CoV-2 and having been vaccinated against COVID-19 had a higher concern about the severity of COVID-19. The parents’ perceived risk that the child could be infected by SARS-CoV-2 was higher in those more concerned about the severity of COVID-19, with an older child, and who had at least one cohabitant positive for COVID-19. Only 38.8% parents were willing to vaccinate their children against COVID-19. Parents who did not need additional information, those with higher education, those who have been vaccinated against COVID-19, those whose child was older, who had received information on this vaccination from physicians, with higher self-reported concern about the severity of COVID-19, and who had a higher perceived risk that their child could be infected by SARS-CoV-2, expressed a greater willingness to vaccinate their child. Overall, 26.3% were high-hesitant, with a PACV-5 score ≥ 7. Respondents who did not get the COVID-19 vaccine, were less educated, with a lower concern about severity of COVID-19, and with a lower perceived risk that their child could be infected by SARS-CoV-2, were more likely to be high-hesitant. New policies and educational programs regarding COVID-19 vaccination for children with chronic conditions are needed to reduce hesitancy and increase vaccination uptake.

Journal ArticleDOI
01 Mar 2022-Vaccines
TL;DR: In this paper , a systematic review was conducted to identify and evaluate the effectiveness of interventions to increase COVID-19 vaccine uptake, including personalizing communications and sending booking reminders via text message.
Abstract: Vaccination is vital to protect the public against COVID-19. The aim of this systematic review is to identify and evaluate the effectiveness of interventions to increase COVID-19 vaccine uptake. We searched a range of databases (Embase, Medline, Psychology & Behavioral Science, PsycInfo, Web of Science and NIH Preprints Portfolio) from March 2020 to July 2021 for studies which reported primary quantitative or qualitative research on interventions to increase COVID-19 vaccine uptake. Outcome measures included vaccination uptake and reported intention to vaccinate. Reviews, position papers, conference abstracts, protocol papers and papers not in English were excluded. The NHLBI quality assessment was used to assess risk of bias. In total, 39 studies across 33 papers met the inclusion criteria. A total of 28 were assessed as good quality. They included interventions relating to communication content, communication delivery, communication presentation, policy or vaccination delivery, with 7 measuring vaccination uptake and 32 measuring vaccination intention. A narrative synthesis was conducted, which highlighted that there is reasonable evidence from studies investigating real behaviour suggesting that personalising communications and sending booking reminders via text message increases vaccine uptake. Findings on vaccination intention are mixed but suggest that communicating uncertainty about the vaccine does not decrease intention, whereas making vaccination mandatory could have a negative impact. Although much of the research used experimental designs, very few measured real behavioural outcomes. Understanding which interventions are most effective amongst vaccine-hesitant populations and in the context of booster vaccinations will be important as vaccine roll outs continue across the world.

Journal ArticleDOI
25 Aug 2022-Vaccines
TL;DR: During the omicron surge, in a population of mostly vaccinated patients treated with molnupiravir or nirmatrelvir/ritonavir, a low rate of hospitalization, death, and adverse drug reactions was observed, even lower than those reported in pivotal trials.
Abstract: Molnupiravir and Nirmatrelvir are the first available oral antivirals (OA) active against SARS-CoV-2. However, the trials evaluating the efficacy of OAs involved patients unvaccinated and infected with variants different from those currently circulating. The purpose of this study is to provide real-life data on the efficacy and safety of OAs during the omicron surge of COVID-19 pandemic in a cohort of mostly vaccinated patients. We conducted a retrospective study on patients with confirmed SARS-CoV-2 infection treated with OAs during the omicron surge in Italy. We enrolled 257 patients. Of these, 146 (56.8%) were treated with molnupiravir and 111 (43.2%) with nirmatrelvir/ritonavir. Patients in molnupiravir group were older, had a lower body mass index, and a higher rate of chronic heart disease than those treated with nirmatrelvir/ritonavir. During the 14-day follow-up, four hospitalizations were recorded (1.6%), three in molnupiravir (2.1%) and 1 in nirmatrelvir/ritonavir (0.9%) group. Only one patient (who had received molnupiravir) died. Median time-to-negativity of nasal swab was 8 days (8 days in nirmatrelvir/ritonavir vs. 10 days in molnupiravir group, p<0.01). Globally, we recorded 37 adverse drug reactions (mainly dysgeusia, diarrhea, and nausea) in 31 of 257 individuals (12.1%). Only two patients (0.8%), both receiving molnupiravir, terminated treatment due to the development of adverse drug reactions. In conclusion, during the omicron surge, in a population of mostly vaccinated patients treated with molnupiravir or nirmatrelvir/ritonavir, we observed a low rate of hospitalization, death, and adverse drug reactions. These rates were even lower than those reported in pivotal trials.

Journal ArticleDOI
Malik Sallam1
19 Aug 2022-Vaccines
TL;DR: In this paper , a single-arm meta-analysis was performed to determine the global prevalence of COVID-19 vaccination hesitancy; the potential factors related to vaccine hesitance were analyzed using a Z-test.
Abstract: Countries worldwide have deployed mass COVID-19 vaccination drives, but there are people who are hesitant to receive the vaccine. Studies assessing the factors associated with COVID-19 vaccination hesitancy are inconclusive. This study aimed to assess the global prevalence of COVID-19 vaccination hesitancy and determine the potential factors associated with such hesitancy. We performed an organized search for relevant articles in PubMed, Scopus, and Web of Science. Extraction of the required information was performed for each study. A single-arm meta-analysis was performed to determine the global prevalence of COVID-19 vaccination hesitancy; the potential factors related to vaccine hesitancy were analyzed using a Z-test. A total of 56 articles were included in our analysis. We found that the global prevalence of COVID-19 vaccination hesitancy was 25%. Being a woman, being a 50-year-old or younger, being single, being unemployed, living in a household with five or more individuals, having an educational attainment lower than an undergraduate degree, having a non-healthcare-related job and considering COVID-19 vaccines to be unsafe were associated with a higher risk of vaccination hesitancy. In contrast, living with children at home, maintaining physical distancing norms, having ever tested for COVID-19, and having a history of influenza vaccination in the past few years were associated with a lower risk of hesitancy to COVID-19 vaccination. Our study provides valuable information on COVID-19 vaccination hesitancy, and we recommend special interventions in the sub-populations with increased risk to reduce COVID-19 vaccine hesitancy.

Journal ArticleDOI
01 Apr 2022-Vaccines
TL;DR: There is a large gap in the literature on the factors influencing the decision of pregnant women to be vaccinated against the COVID-19, and targeted information campaigns are essential to improve trust and build vaccine literacy among pregnant women.
Abstract: Background: Mass vaccination against the COVID-19 is essential to control the pandemic. COVID-19 vaccines are recommended now during pregnancy to prevent adverse outcomes. Objective: To evaluate the evidence from the literature regarding the uptake of COVID-19 vaccination among pregnant women. Methods: We conducted a systematic review following the Preferred Reporting Items for Systematic Reviews and Meta-Analysis guidelines. We searched PubMed, Medline, Scopus, ProQuest, Web of Science, CINAHL, and a pre-print service (medRxiv) from inception to March 23, 2022. We included quantitative studies reporting COVID-19 vaccination uptake among pregnant women, studies that examine predictors of COVID-19 vaccination uptake and studies that examine reasons for decline of vaccination. We performed meta-analysis to estimate the overall proportion of vaccinated pregnant women against the COVID-19. Results: We found 11 studies including 703,004 pregnant women. The overall proportion of vaccinated pregnant women against the COVID-19 was 27.5% (95% CI: 18.8-37.0%). The pooled proportion for studies that were conducted in Israel was higher than the proportion for studies that were conducted in USA and other countries. Predictors of COVID-19 vaccination uptake were older age, ethnicity, race, trust in COVID-19 vaccines, and fear of COVID-19 during pregnancy. On the other hand, mistrust in the government, diagnosis with COVID-19 during pregnancy, and worry about the safety and the side effects of the COVID-19 vaccines were reasons for decline of vaccination. Conclusions: The global COVID-19 vaccination prevalence in pregnant women is low. There is a large gap in the literature on the factors influencing the decision of pregnant women to be vaccinated against the COVID-19. Targeted information campaigns are essential to improve trust and build vaccine literacy among pregnant women. Given the ongoing high case rates and the known increased risks of COVID-19 in pregnant women, our findings could help policy makers to improve the acceptance rate of COVID-19 vaccines in pregnant women especially in vulnerable subgroups.

Journal ArticleDOI
29 Aug 2022-Vaccines
TL;DR: There is still a need to develop an effective and safe new generation of vaccines specific for monkeypox that are killed or developed into a mRNA vaccine before monkeypox is declared a pandemic.
Abstract: (1) Background: The monkeypox virus (MPV) is a double-stranded DNA virus belonging to the Poxviridae family, Chordopoxvirinae subfamily, and Orthopoxvirus genus. It was called monkeypox because it was first discovered in monkeys, in a Danish laboratory, in 1958. However, the actual reservoir for MPV is still unknown. (2) Methods and Results: We have reviewed the existing literature on the options for Monkeypox virus. There are three available vaccines for orthopoxviruses—ACAM2000, JYNNEOS, and LC16—with the first being a replicating vaccine and the latter being non- or minimally replicating. (3) Conclusions: Smallpox vaccinations previously provided coincidental immunity to MPV. ACAM2000 (a live-attenuated replicating vaccine) and JYNNEOS (a live-attenuated, nonreplicating vaccine) are two US FDA-approved vaccines that can prevent monkeypox. However, ACAM2000 may cause serious side effects, including cardiac problems, whereas JYNNEOS is associated with fewer complications. The recent outbreaks across the globe have once again highlighted the need for constant monitoring and the development of novel prophylactic and therapeutic modalities. Based on available data, there is still a need to develop an effective and safe new generation of vaccines specific for monkeypox that are killed or developed into a mRNA vaccine before monkeypox is declared a pandemic.

Journal ArticleDOI
22 Jan 2022-Vaccines
TL;DR: This review attempts to assemble and summarize all the relevant information on chicken gut health to provide deeper insights into various aspects of gut health and highlighted the most pertinent factors related to the field performance of broiler chickens.
Abstract: “Gut health” refers to the physical state and physiological function of the gastrointestinal tract and in the livestock system; this topic is often focused on the complex interacting components of the intestinal system that influence animal growth performance and host-microbial homeostasis. Regardless, there is an increasing need to better understand the complexity of the intestinal system and the various factors that influence gut health, since the intestine is the largest immune and neuroendocrine organ that interacts with the most complex microbiome population. As we face the post-antibiotic growth promoters (AGP) era in many countries of the world, livestock need more options to deal with food security, food safety, and antibiotic resilience to maintain agricultural sustainability to feed the increasing human population. Furthermore, developing novel antibiotic alternative strategies needs a comprehensive understanding of how this complex system maintains homeostasis as we face unpredictable changes in external factors like antibiotic-resistant microbes, farming practices, climate changes, and consumers’ preferences for food. In this review, we attempt to assemble and summarize all the relevant information on chicken gut health to provide deeper insights into various aspects of gut health. Due to the broad and complex nature of the concept of “gut health”, we have highlighted the most pertinent factors related to the field performance of broiler chickens.

Journal ArticleDOI
01 Aug 2022-Vaccines
TL;DR: The most predominant predictors of vaccine hesitancy were a lower perceived risk of getting infected, a lower level of institutional trust, not being vaccinated against influenza, lower levels of perceived severity of COVID-19, or stronger beliefs that the vaccination would cause side effects or be unsafe.
Abstract: Background: vaccine hesitancy is defined as a delay in the acceptance or refusal of vaccination, even though immunisation is a determinant in reducing the mortality and morbidity associated with Coronavirus Disease 2019 (COVID-19). Aim: to identify and analyse the predictors of COVID-19 vaccine acceptance and/or hesitancy. Methods: a systematic review according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) criteria. Keywords: vaccine and (COVID or SARS) and (acceptance or acceptability or willingness or hesitancy or refusal) and (multivariate or regression) and (questionnaire or survey) and national. Databases/resources: PubMed, DOAJ, SciELO and b-on. Timeframe: March 2020–2022. Inclusion criteria: general population, questionnaire-based, calculation of a multivariate regression model and national studies. Quality assessment: application of the National Heart, Lung, and Blood institute (NHLBI) tool. Results: a total of 37 studies were selected, whose overall rate was fair. The most predominant predictors of vaccine hesitancy were a lower perceived risk of getting infected, a lower level of institutional trust, not being vaccinated against influenza, lower levels of perceived severity of COVID-19, or stronger beliefs that the vaccination would cause side effects or be unsafe. Discussion and conclusion: the identified predictors can be used to design tailored health policies and/or public health interventions, or to evaluate subjects’ vaccine hesitancy.

Journal ArticleDOI
23 Feb 2022-Vaccines
TL;DR: This study showed that most vaccines have comparable effectiveness, and it is purported that mass vaccination may help to end this pandemic.
Abstract: The coronavirus disease 2019 (COVID-19) pandemic has threatened global health and prompted the need for mass vaccination. We aimed to assess the efficacy and effectiveness of COVID-19 vaccines to prevent mortality and reduce the risk of developing severe disease after the 1st and 2nd doses. From conception to 28 June 2021, we searched PubMed, Cochrane, EBSCO, Scopus, ProQuest, Web of Science, WHO-ICTRP, and Google Scholar. We included both observational and randomized controlled trials. The pooled vaccine efficacy and effectiveness following vaccination, as well as their 95 percent confidence intervals (CI), were estimated using the random-effects model. In total, 22 of the 21,567 screened articles were eligible for quantitative analysis. Mortality 7 and 14 days after full vaccination decreased significantly among the vaccinated group compared to the unvaccinated group (OR = 0.10, ([95% CI, 0.04–0.27], I2 = 54%) and (OR = 0.46, [95% CI, 0.35–0.61], I2 = 0%), respectively. The probability of having severe disease one or two weeks after 2nd dose decreased significantly (OR = 0.29 [95% CI, 0.19–0.46], I2 = 25%) and (OR = 0.08 [95% CI, 0.03–0.25], I2 = 74%), respectively. The incidence of infection any time after the 1st and 2nd doses diminished significantly (OR = 0.14 [95% CI, 0.07–0.4], I2 = 100%) and (OR = 0.179 [95% CI, 0.15–0.19], I2 = 98%), respectively. Also, incidence of infection one week after 2nd dose decreased significantly, (OR = 0.04, [95% CI (0.01–0.2], I2 = 100%). After meta-regression, the type of vaccine and country were the main predictors of outcome [non-mRNA type, ß = 2.99, p = 0.0001; country UK, ß = −0.75, p = 0.038; country USA, ß = 0.8, p = 0.02]. This study showed that most vaccines have comparable effectiveness, and it is purported that mass vaccination may help to end this pandemic.

Journal ArticleDOI
21 Jan 2022-Vaccines
TL;DR: This article identified the prominent themes about vaccine hesitancy and refusal on social media posts in Turkish during the COVID-19 pandemic and found that 90.5% of the tweets were about vaccines, 22.0% of tweets included at least one anti-vaccination theme.
Abstract: Twitter is a useful source for detecting anti-vaccine content due to the increasing prevalence of these arguments on social media. We aimed to identify the prominent themes about vaccine hesitancy and refusal on social media posts in Turkish during the COVID-19 pandemic. In this qualitative study, we collected public tweets (n = 551,245) that contained a vaccine-related keyword and had been published between 9 December 2020 and 8 January 2021 through the Twitter API. A random sample of tweets (n = 1041) was selected and analyzed by four researchers with the content analysis method. We found that 90.5% of the tweets were about vaccines, 22.6% (n = 213) of the tweets mentioned at least one COVID-19 vaccine by name, and the most frequently mentioned COVID-19 vaccine was CoronaVac (51.2%). We found that 22.0% (n = 207) of the tweets included at least one anti-vaccination theme. Poor scientific processes (21.7%), conspiracy theories (16.4%), and suspicions towards manufacturers (15.5%) were the most frequently mentioned themes. The most co-occurring themes were "poor scientific process" with "suspicion towards manufacturers" (n = 9), and "suspicion towards health authorities" (n = 5). This study may be helpful for health managers, assisting them to identify the major concerns of the population and organize preventive measures through the significant role of social media in early spread of information about vaccine hesitancy and anti-vaccination attitudes.

Journal ArticleDOI
01 Apr 2022-Vaccines
TL;DR: The COVID-19 pandemic has increased intention to vaccinate against influenza internationally, and the pandemic could be a window of opportunity to promote influenza vaccination and decrease vaccine hesitancy.
Abstract: Poorer outcomes have been reported with COVID-19 and influenza coinfections. As the COVID-19 pandemic rages on, protection against influenza by vaccination is becoming increasingly important. This study examines how COVID-19 has influenced influenza vaccination intentions from a global perspective. A literature search was conducted on Embase, PubMed, and CNKI from 1 January 2019 to 31 December 2021 for articles reporting rates of influenza vaccination pre-COVID-19 (19/20 season), and intention and/or uptake of influenza vaccination post-COVID-19 (20/21 season). The changes in vaccination intention and reasons for changes were reported. Subgroup analyses were performed by region, gender, age, and occupation. Newcastle Ottawa Scale was used for quality assessment of the articles. Twenty-seven studies with 39,193 participants were included. Among 22 studies reporting intention to vaccinate in 20/21, there was increased intention to vaccinate (RR 1.50, 95% CI 1.32–1.69, p < 0.001) regardless of age, gender, and occupation. The remaining five studies reporting vaccination intention and uptake in 20/21 showed a similar increase (RR 1.68, 95%CI 1.20–2.36). Important determinants include historical vaccine acceptance, and perception of influenza severity and vaccine safety. The COVID-19 pandemic has increased intention to vaccinate against influenza internationally. The pandemic could be a window of opportunity to promote influenza vaccination and decrease vaccine hesitancy.

Journal ArticleDOI
Yirui Ma, J. Deng, Qiao Liu, Min Du, Min Li, Jue Liu 
01 Feb 2022-Vaccines
TL;DR: It is found that vaccination prevented pregnant women from SARS-CoV-2 infection and COVID-19-related hospitalization and Messenger-RNA vaccines could reduce the risk of infection in pregnant women.
Abstract: We aimed to assess the effectiveness and safety of coronavirus disease 2019 (COVID-19) vaccines for pregnant women in real-world studies. We searched for observational studies about the effectiveness and safety of COVID-19 vaccines among vaccinated pregnant women from inception to 6 November 2021. A total of 6 studies were included. We found that vaccination prevented pregnant women from SARS-CoV-2 infection (OR = 0.50, 95% CI, 0.35–0.79) and COVID-19-related hospitalization (OR = 0.50, 95% CI, 0.31–0.82). Messenger-RNA vaccines could reduce the risk of infection in pregnant women (OR = 0.13, 95% CI, 0.03–0.57). No adverse events of COVID-19 vaccination were found on pregnant, fetal, or neonatal outcomes. Our analysis confirmed the effectiveness and safety of COVID-19 vaccines for pregnant women. Policy makers should formulate targeted strategies to improve vaccine coverage in pregnant women.

Journal ArticleDOI
01 May 2022-Vaccines
TL;DR: Research into adjuvants could play a leading role in the production of increasingly effective vaccines as modern technologies such as nanotechnologies and molecular biology have forcefully entered the production processes of both antigen and adjuvant components.
Abstract: Vaccinations are one of the most important preventive tools against infectious diseases. Over time, many different types of vaccines have been developed concerning the antigen component. Adjuvants are essential elements that increase the efficacy of vaccination practises through many different actions, especially acting as carriers, depots, and stimulators of immune responses. For many years, few adjuvants have been included in vaccines, with aluminium salts being the most commonly used adjuvant. However, recent research has focused its attention on many different new compounds with effective adjuvant properties and improved safety. Modern technologies such as nanotechnologies and molecular biology have forcefully entered the production processes of both antigen and adjuvant components, thereby improving vaccine efficacy. Microparticles, emulsions, and immune stimulators are currently in the spotlight for their huge potential in vaccine production. Although studies have reported some potential side effects of vaccine adjuvants such as the recently recognised ASIA syndrome, the huge worth of vaccines remains unquestionable. Indeed, the recent COVID-19 pandemic has highlighted the importance of vaccines, especially in regard to managing future potential pandemics. In this field, research into adjuvants could play a leading role in the production of increasingly effective vaccines.

Journal ArticleDOI
01 Aug 2022-Vaccines
TL;DR: Vaccination will be a key strategy for mitigating MVIH given the current rapid global spread of monkeypox, the existence of efficacious vaccines, and the uncertain risk–benefit profile of current antivirals.
Abstract: Monkeypox virus infection in humans (MVIH) is currently an evolving public health concern given that >3000 MVIH cases have been reported in >50 countries globally, and the World Health Organization declared monkeypox a global health emergency on 23 July 2022. Adults (≥16 years old) usually have mild disease in contemporary studies, with a pooled case fatality rate of 0.03% (1/2941 cases). In comparison, poorer outcomes have been reported in children <16 years old (pooled case fatality rate 19% (4/21 cases)), immunocompromised patients, and pregnant women, with high rates of fetal demise in this group. Monkeypox-specific treatments include oral or intravenous tecovirimat, intravenous or topical cidofovir, oral brincidofovir, and vaccinia immunoglobulin, but the overall risk–benefit balance of monkeypox-specific treatment is unclear. Two effective vaccines exist for the prevention of MVIH: modified vaccinia Ankara and ACAM2000. Most probably, vaccination will be a key strategy for mitigating MVIH given the current rapid global spread of monkeypox, the existence of efficacious vaccines, and the uncertain risk–benefit profile of current antivirals. Priority groups for vaccination should include healthcare workers at high risk for occupational exposure, immunocompromised patients, and children. Vaccination strategies include pre-exposure vaccination, post-exposure prophylaxis, and ring vaccination of close contacts.