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Journal ArticleDOI

Immunogenicity and safety of a severe acute respiratory syndrome coronavirus 2 inactivated vaccine in healthy adults: randomized, double-blind, and placebo-controlled phase 1 and phase 2 clinical trials.

TL;DR: In this article, the authors report the immunogenicity and safety of an inactivated SARS-CoV-2 vaccine, KCONVAC, in healthy adults, in a phase 1 and phase 2 randomized, double-blind, and placebo-controlled trial.
Abstract: BACKGROUND: The significant morbidity and mortality resulted from the infection of a severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) call for urgent development of effective and safe vaccines. We report the immunogenicity and safety of an inactivated SARS-CoV-2 vaccine, KCONVAC, in healthy adults. METHODS: Phase 1 and phase 2 randomized, double-blind, and placebo-controlled trials of KCONVAC were conducted in healthy Chinese adults aged 18 to 59 years. The participants in the phase 1 trial were randomized to receive two doses, one each on Days 0 and 14, of either KCONVAC (5 or 10 µg/dose) or placebo. The participants in the phase 2 trial were randomized to receive either KCONVAC (at 5 or 10 µg/dose) or placebo on Days 0 and 14 (0/14 regimen) or Days 0 and 28 (0/28 regimen). In the phase 1 trial, the primary safety endpoint was the proportion of participants experiencing adverse reactions/events within 28 days following the administration of each dose. In the phase 2 trial, the primary immunogenicity endpoints were neutralization antibody seroconversion and titer and anti-receptor-binding domain immunoglobulin G seroconversion at 28 days after the second dose. RESULTS: In the phase 1 trial, 60 participants were enrolled and received at least one dose of 5-µg vaccine (n = 24), 10-µg vaccine (n = 24), or placebo (n = 12). In the phase 2 trial, 500 participants were enrolled and received at least one dose of 5-µg vaccine (n = 100 for 0/14 or 0/28 regimens), 10-µg vaccine (n = 100 for each regimen), or placebo (n = 50 for each regimen). In the phase 1 trial, 13 (54%), 11 (46%), and seven (7/12) participants reported at least one adverse event (AE) after receiving 5-, 10-µg vaccine, or placebo, respectively. In the phase 2 trial, 16 (16%), 19 (19%), and nine (18%) 0/14-regimen participants reported at least one AE after receiving 5-, 10-µg vaccine, or placebo, respectively. Similar AE incidences were observed in the three 0/28-regimen treatment groups. No AEs with an intensity of grade 3+ were reported, expect for one vaccine-unrelated serious AE (foot fracture) reported in the phase 1 trial. KCONVAC induced significant antibody responses; 0/28 regimen showed a higher immune responses than that did 0/14 regimen after receiving two vaccine doses. CONCLUSIONS: Both doses of KCONVAC are well tolerated and able to induce robust immune responses in healthy adults. These results support testing 5-µg vaccine in the 0/28 regimen in an upcoming phase 3 efficacy trial. TRIAL REGISTRATION: http://www.chictr.org.cn/index.aspx (No. ChiCTR2000038804, http://www.chictr.org.cn/showproj.aspx?proj=62350; No. ChiCTR2000039462, http://www.chictr.org.cn/showproj.aspx?proj=63353).
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Journal ArticleDOI
TL;DR: In this article, a comprehensive overview of the safety profile of COVID-19 vaccines by using meta-analysis technique was provided by using PubMed, Embase, Web of Science, PMC, official regulatory websites, and post-authorization safety surveillance data.
Abstract: BACKGROUND: The rapid process of research and development and lack of follow-up time post-vaccination aroused great public concern about the safety profile of COVID-19 vaccine candidates. To provide comprehensive overview of the safety profile of COVID-19 vaccines by using meta-analysis technique. METHODS: English-language articles and results posted on PubMed, Embase, Web of Science, PMC, official regulatory websites, and post-authorization safety surveillance data were searched through June 12, 2021. Publications disclosing safety data of COVID-19 candidate vaccines in humans were included. A meta-analysis of proportions was performed to estimate the pooled incidence and the pooled rate ratio (RR) of safety outcomes of COVID-19 vaccines using different platforms. RESULTS: A total of 87 publications with safety data from clinical trials and post-authorization studies of 19 COVID-19 vaccines on 6 different platforms were included. The pooled rates of local and systemic reactions were significantly lower among inactivated vaccines (23.7%, 21.0%), protein subunit vaccines (33.0%, 22.3%), and DNA vaccines (39.5%, 29.3%), compared to RNA vaccines (89.4%, 83.3%), non-replicating vector vaccines (55.9%, 66.3%), and virus-like particle vaccines (100.0%, 78.9%). Solicited injection-site pain was the most common local reactions, and fatigue and headache were the most common systemic reactions. The frequency of vaccine-related serious adverse events was low (< 0.1%) and balanced between treatment groups. Vaccine platforms and age groups of vaccine recipients accounted for much of the heterogeneity in safety profiles between COVID-19 vaccines. Reporting rates of adverse events from post-authorization observational studies were similar to results from clinical trials. Crude reporting rates of adverse events from post-authorization safety monitoring (passive surveillance) were lower than in clinical trials and varied between countries. CONCLUSIONS: Available evidence indicates that eligible COVID-19 vaccines have an acceptable short-term safety profile. Additional studies and long-term population-level surveillance are strongly encouraged to further define the safety profile of COVID-19 vaccines.

117 citations

Journal ArticleDOI
21 Jan 2022-PLOS ONE
TL;DR: The evidence suggests that all the included vaccines are effective in preventing COVID-19, but viral vector vaccines seem most effective in reducing mortality.
Abstract: Background COVID-19 is rapidly spreading causing extensive burdens across the world. Effective vaccines to prevent COVID-19 are urgently needed. Methods and findings Our objective was to assess the effectiveness and safety of COVID-19 vaccines through analyses of all currently available randomized clinical trials. We searched the databases CENTRAL, MEDLINE, Embase, and other sources from inception to June 17, 2021 for randomized clinical trials assessing vaccines for COVID-19. At least two independent reviewers screened studies, extracted data, and assessed risks of bias. We conducted meta-analyses, network meta-analyses, and Trial Sequential Analyses (TSA). Our primary outcomes included all-cause mortality, vaccine efficacy, and serious adverse events. We assessed the certainty of evidence with GRADE. We identified 46 trials; 35 trials randomizing 219 864 participants could be included in our analyses. Our meta-analyses showed that mRNA vaccines (efficacy, 95% [95% confidence interval (CI), 92% to 97%]; 71 514 participants; 3 trials; moderate certainty); inactivated vaccines (efficacy, 61% [95% CI, 52% to 68%]; 48 029 participants; 3 trials; moderate certainty); protein subunit vaccines (efficacy, 77% [95% CI, −5% to 95%]; 17 737 participants; 2 trials; low certainty); and viral vector vaccines (efficacy 68% [95% CI, 61% to 74%]; 71 401 participants; 5 trials; low certainty) prevented COVID-19. Viral vector vaccines decreased mortality (risk ratio, 0.25 [95% CI 0.09 to 0.67]; 67 563 participants; 3 trials, low certainty), but comparable data on inactivated, mRNA, and protein subunit vaccines were imprecise. None of the vaccines showed evidence of a difference on serious adverse events, but observational evidence suggested rare serious adverse events. All the vaccines increased the risk of non-serious adverse events. Conclusions The evidence suggests that all the included vaccines are effective in preventing COVID-19. The mRNA vaccines seem most effective in preventing COVID-19, but viral vector vaccines seem most effective in reducing mortality. Further trials and longer follow-up are necessary to provide better insight into the safety profile of these vaccines.

50 citations

Journal ArticleDOI
13 Oct 2021
TL;DR: In this article, the authors investigated the infectivity and antigenicity of ten emerging SARS-CoV-2 variants-B.1.5, B.1,1.7, P.2(Zeta), P.429(Epsilon), B.525, B1.525 and B.526 in Calu-3 cells, and highlighted the importance of E484K mutation.
Abstract: Emerging mutations in SARS-CoV-2 cause several waves of COVID-19 pandemic. Here we investigate the infectivity and antigenicity of ten emerging SARS-CoV-2 variants-B.1.1.298, B.1.1.7(Alpha), B.1.351(Beta), P.1(Gamma), P.2(Zeta), B.1.429(Epsilon), B.1.525(Eta), B.1.526-1(Iota), B.1.526-2(Iota), B.1.1.318-and seven corresponding single amino acid mutations in the receptor-binding domain using SARS-CoV-2 pseudovirus. The results indicate that the pseudovirus of most of the SARS-CoV-2 variants (except B.1.1.298) display slightly increased infectivity in human and monkey cell lines, especially B.1.351, B.1.525 and B.1.526 in Calu-3 cells. The K417N/T, N501Y, or E484K-carrying variants exhibit significantly increased abilities to infect mouse ACE2-overexpressing cells. The activities of furin, TMPRSS2, and cathepsin L are increased against most of the variants. RBD amino acid mutations comprising K417T/N, L452R, Y453F, S477N, E484K, and N501Y cause significant immune escape from 11 of 13 monoclonal antibodies. However, the resistance to neutralization by convalescent serum or vaccines elicited serum is mainly caused by the E484K mutation. The convalescent serum from B.1.1.7- and B.1.351-infected patients neutralized the variants themselves better than other SARS-CoV-2 variants. Our study provides insights regarding therapeutic antibodies and vaccines, and highlights the importance of E484K mutation.

39 citations

Journal ArticleDOI
TL;DR: In this paper , the authors found that vaccines are associated with a two-fold risk of developing headache within 7 days from injection, and the lack of difference between vaccine types enable to hypothesize that headache is secondary to systemic immunological reaction than to a vaccine-type specific reaction.
Abstract: Abstract Background Vaccines against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) are used to reduce the risk of developing Coronavirus Disease 2019 (COVID-19). Despite the significant benefits in terms of reduced risk of hospitalization and death, different adverse events may present after vaccination: among them, headache is one of the most common, but nowadays there is no summary presentation of its incidence and no description of its main features. Methods We searched PubMed and EMBASE covering the period between January 1 st 2020 and August 6 th , 2021, looking for record in English and with an abstract and using three main search terms (with specific variations): COVID-19/SARS-CoV-2; Vaccination; headache/adverse events. We selected manuscript including information on subjects developing headache after injection, and such information had to be derived from a structured form (i.e. no free reporting). Pooled estimates and 95% confidence intervals were calculated. Analyses were carried out by vaccine vs. placebo, by first vs. second dose, and by mRNA-based vs. “traditional” vaccines; finally, we addressed the impact of age and gender on post-vaccine headache onset. Results Out of 9338 records, 84 papers were included in the review, accounting for 1.57 million participants, 94% of whom received BNT162b2 or ChAdOx1. Headache was generally the third most common AE: it was detected in 22% (95% CI 18–27%) of subjects after the first dose of vaccine and in 29% (95% CI 23–35%) after the second, with an extreme heterogeneity. Those receiving placebo reported headache in 10–12% of cases. No differences were detected across different vaccines or by mRNA-based vs. “traditional” ones. None of the studies reported information on headache features. A lower prevalence of headache after the first injection of BNT162b2 among older participants was shown. Conclusions Our results show that vaccines are associated to a two-fold risk of developing headache within 7 days from injection, and the lack of difference between vaccine types enable to hypothesize that headache is secondary to systemic immunological reaction than to a vaccine-type specific reaction. Some descriptions report onset within the first 24 h and that in around one-third of the cases, headache has migraine-like features with pulsating quality, phono and photophobia; in 40–60% of the cases aggravation with activity is observed. The majority of patients used some medication to treat headache, the one perceived as the most effective being acetylsalicylic acid.

29 citations

Journal ArticleDOI
TL;DR: Based on the findings, mucocutaneous adverse events were mostly non‐significant, self‐limiting reactions, and for the more uncommon moderate to severe reactions, guidelines and consensus position papers could be of great importance to provide those at higher risks and those with specific worries of flare‐ups or inefficient immunization with sufficient recommendations to safely schedule their vaccine doses, or avoid vaccination if they have the discussed contra‐indications.
Abstract: With dermatologic side effects being fairly prevalent following vaccination against COVID‐19, and the multitude of studies aiming to report and analyze these adverse events, the need for an extensive investigation on previous studies seemed urgent, in order to provide a thorough body of information about these post‐COVID‐19 immunization mucocutaneous reactions. To achieve this goal, a comprehensive electronic search was performed through the international databases including Medline (PubMed), Scopus, Cochrane, Web of science, and Google scholar on July 12, 2021, and all articles regarding mucocutaneous manifestations and considerations after COVID‐19 vaccine administration were retrieved using the following keywords: COVID‐19 vaccine, dermatology considerations and mucocutaneous manifestations. A total of 917 records were retrieved and a final number of 180 articles were included in data extraction. Mild, moderate, severe and potentially life‐threatening adverse events have been reported following immunization with COVID vaccines, through case reports, case series, observational studies, randomized clinical trials, and further recommendations and consensus position papers regarding vaccination. In this systematic review, we categorized these results in detail into five elaborate tables, making what we believe to be an extensively informative, unprecedented set of data on this topic. Based on our findings, in the viewpoint of the pros and cons of vaccination, mucocutaneous adverse events were mostly non‐significant, self‐limiting reactions, and for the more uncommon moderate to severe reactions, guidelines and consensus position papers could be of great importance to provide those at higher risks and those with specific worries of flare‐ups or inefficient immunization, with sufficient recommendations to safely schedule their vaccine doses, or avoid vaccination if they have the discussed contra‐indications.

27 citations

References
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Journal ArticleDOI
TL;DR: Human airway epithelial cells were used to isolate a novel coronavirus, named 2019-nCoV, which formed a clade within the subgenus sarbecovirus, Orthocoronavirinae subfamily, which is the seventh member of the family of coronaviruses that infect humans.
Abstract: In December 2019, a cluster of patients with pneumonia of unknown cause was linked to a seafood wholesale market in Wuhan, China. A previously unknown betacoronavirus was discovered through the use of unbiased sequencing in samples from patients with pneumonia. Human airway epithelial cells were used to isolate a novel coronavirus, named 2019-nCoV, which formed a clade within the subgenus sarbecovirus, Orthocoronavirinae subfamily. Different from both MERS-CoV and SARS-CoV, 2019-nCoV is the seventh member of the family of coronaviruses that infect humans. Enhanced surveillance and further investigation are ongoing. (Funded by the National Key Research and Development Program of China and the National Major Project for Control and Prevention of Infectious Disease in China.).

21,455 citations

Journal ArticleDOI
TL;DR: A two-dose regimen of BNT162b2 conferred 95% protection against Covid-19 in persons 16 years of age or older and safety over a median of 2 months was similar to that of other viral vaccines.
Abstract: Background Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection and the resulting coronavirus disease 2019 (Covid-19) have afflicted tens of millions of people in a world...

10,274 citations

Journal ArticleDOI
TL;DR: The mRNA-1273 vaccine induced anti-SARS-CoV-2 immune responses in all participants, and no trial-limiting safety concerns were identified, which support further development of this vaccine.
Abstract: Background The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) emerged in late 2019 and spread globally, prompting an international effort to accelerate development of a vacci...

2,556 citations

Journal ArticleDOI
TL;DR: IgG-polymorphisms and post-translational modification of the antibodies in the form of glycosylation, affect IgG-function will be the focus of the current review.
Abstract: Of the five immunoglobulin isotypes, Immunoglobulin G (IgG) is most abundant in human serum. The four subclasses, IgG1, IgG2, IgG3 and IgG4 which are highly conserved, differ in their constant region, particularly in their hinges and upper CH2 domains. These regions are involved in binding to both IgG-Fc receptor (FcγR) and C1q. As a result, the different subclasses have different effector functions, both in terms of triggering FcγR-expressing cells, resulting in phagocytosis or Antibody-dependent cell-mediated cytotoxicity (ADCC), and activating complement. The Fc-regions also contain a binding epitope for the neonatal Fc-receptor (FcRn), responsible for the extended half-life, placental transport, and bidirectional transport of IgG to mucosal surfaces. However, FcRn is also expressed in myeloid cells, where it participates in both phagocytosis and antigen presentation together with classical FcγR and complement. How these properties, IgG-polymorphisms and post-translational modification of the antibodies in the form of glycosylation, affect IgG-function, will be the focus of the current review.

1,834 citations

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