Inactivated Influenza Virus Vaccines in Children
TL;DR: The data show that killed influenza vaccines in children are safe, immunogenic, effective, and potentially cost-saving, and studies suggest that use of killed vaccines among children is cost- saving.
Abstract: Healthy children aged ⩽2 years have hospitalization rates during influenza periods 12 times those of older children and comparable to rates in the elderly population. In 2003, killed influenza vaccines were “recommended" for children with high-risk conditions and were ”encouraged" for children aged 6–23 months. Studies involving several thousand children show that split-virus vaccines are safe and immunogenic in healthy children aged ⩾6 months and in high-risk children. In children aged ⩽9 years, 2 doses of vaccine are required initially to achieve maximum protection. Studies of children aged 6 months to 15 years show vaccine efficacies of 31%–91% against influenza A and 45% against influenza B. Among children attending day care, a reduction in the rate of acute otitis media of 32%–36% was demonstrated. Studies suggest that use of killed vaccines among children is cost-saving. In conclusion, the data show that killed influenza vaccines in children are safe, immunogenic, effective, and potentially cost-saving.
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TL;DR: One dose of vaccine was highly immunogenic in adults, suggesting that it afforded sufficient protection against this pandemic influenza A H1N1 virus.
245 citations
TL;DR: The serologic conversion rate to influenza vaccine in patients with IBD ranged from 33% to 85%.
170 citations
TL;DR: It is shown that plasmacytoid dendritic cells (pDCs) and type I interferon (IFN)–mediated signaling delineate the immunogenicity of live attenuated virus, inactivated whole-virus (WV), and split-Virus vaccines.
Abstract: A variety of different vaccine types are available for H1N1 influenza A virus infections; however, their immunological mechanisms of action remain unclear. Here, we show that plasmacytoid dendritic cells (pDCs) and type I interferon (IFN)-mediated signaling delineate the immunogenicity of live attenuated virus, inactivated whole-virus (WV), and split-virus vaccines. Although Toll-like receptor 7 acted as the adjuvant receptor for the immunogenicity of both live virus and WV vaccines, the requirement for type I IFN production by pDCs for the immunogenicity of the vaccines was restricted to WV. A split vaccine commonly used in humans failed to immunize naive mice, but a pDC-activating adjuvant could restore immunogenicity. In blood from human adults, however, split vaccine alone could recall memory T cell responses, underscoring the importance of this adjuvant pathway for primary, but not secondary, vaccination.
125 citations
Cites result from "Inactivated Influenza Virus Vaccine..."
...These results might explain in part the wellknown fact that the efficacy of adjuvant-less SV is lower in young children than in adults (7), in which SV is simply boosting the memory T and/or B cell responses....
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TL;DR: It is emphasized that antibody responses to vaccine are impaired in subjects treated with rituximab and the concept that B cell recovery influences influenza vaccine responsiveness is supported.
Abstract: The efficacy of influenza vaccination in patients treated with rituximab is a clinically important question. Rheumatology clinics are populated with patients receiving rituximab for a broad array of disorders. Although several studies have explored the efficacy of other vaccines in rituximab-treated populations, results have been conflicting. We wished to define influenza vaccine efficacy in a rituximab-treated cohort. We examined 17 evaluable subjects treated with rituximab for rheumatologic conditions. T cell subsets, B cells subsets, T cell function, and B cell function were evaluated at specific time points along with hemagglutinination inhibition titers after receiving the standard inactivated influenza vaccine. T cell subset counts were significantly different than controls but did not change with rituximab. B cells depleted in all patients but were in various stages of recovery at the time of vaccination. Influenza vaccine responsiveness was poor overall, with only 16 % of subjects having a four-fold increase in titer. Pre-existing titers were retained throughout the study, however. The ability to respond to the influenza vaccine appeared to be related to the degree of B cell recovery at the time of vaccination. This study emphasizes that antibody responses to vaccine are impaired in subjects treated with rituximab and supports the concept that B cell recovery influences influenza vaccine responsiveness.
107 citations
TL;DR: Needs include ensuring antigenic matches of vaccine and epidemic viruses each season, enhancing immunization rates, and providing new and improved vaccines and immunization approaches for the varied populations and circumstances globally.
104 citations
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Journal Article•
TL;DR: This report updates the 2000 recommendations by the Advisory Committee on Immunization Practices on the use of influenza vaccine and antiviral agents with new or updated information regarding the cost-effectiveness of influenza vaccination and the 2001-2002 trivalent vaccine virus strains.
Abstract: This report updates the 2002 recommendations by the Advisory Committee on Immunization Practices (ACIP) on the use of influenza vaccine and antiviral agents (CDC. Prevention and Control of Influenza: Recommendations of the Advisory Committee on Immunization Practices [ACIP]. MMWR 2002;51 [No. RR-3]:1-31). The 2003 recommendations include new or updated information regarding 1) the timing of influenza vaccination by age and risk group; 2) influenza vaccine for children aged 6-23 months; 3) the 2003-2004 trivalent inactivated vaccine virus strains: A/Moscow/10/99 (H3N2)-like, A/New Caledonia/20/99 (H1N1)-like, and B/Hong Kong/330/2001-like antigens (for the A/Moscow/10/99 [H3N2]-like antigen, manufacturers will use the antigenically equivalent A/Panama/2007/99 [H3N2] virus, and for the B/Hong Kong/330/2001-like antigen, manufacturers will use either B/Hong Kong/330/2001 or the antigenically equivalent B/Hong Kong/1434/2002); 4) availability of certain influenza vaccine doses with reduced thimerosal content, including single 0.25 mL-dose syringes; and 5) manufacturers of influenza vaccine for the U.S. market. Although the optimal time to vaccinate against influenza is October and November, vaccination in December and later continues to be strongly recommended A link to this report and other information regarding influenza can be accessed at http://www.cdc.gov/ncidod/diseases/flu/fluvirus.htm.
5,334 citations
TL;DR: Mortality associated with both influenza and RSV circulation disproportionately affects elderly persons, and influenza deaths have increased substantially in the last 2 decades, in part because of aging of the population, highlighting the need for better prevention measures, including more effective vaccines and vaccination programs for elderly persons.
Abstract: Context Influenza and respiratory syncytial virus (RSV) cause substantial morbidity and mortality. Statistical methods used to estimate deaths in the United States attributable to influenza have not accounted for RSV circulation. Objective To develop a statistical model using national mortality and viral surveillance data to estimate annual influenza- and RSV-associated deaths in the United States, by age group, virus, and influenza type and subtype. Design, Setting, and Population Age-specific Poisson regression models using national viral surveillance data for the 1976-1977 through 1998-1999 seasons were used to estimate influenza-associated deaths. Influenza- and RSV-associated deaths were simultaneously estimated for the 1990-1991 through 1998-1999 seasons. Main Outcome Measures Attributable deaths for 3 categories: underlying pneumonia and influenza, underlying respiratory and circulatory, and all causes. Results Annual estimates of influenza-associated deaths increased significantly between the 1976-1977 and 1998-1999 seasons for all 3 death categories (P Conclusions Mortality associated with both influenza and RSV circulation disproportionately affects elderly persons. Influenza deaths have increased substantially in the last 2 decades, in part because of aging of the population, underscoring the need for better prevention measures, including more effective vaccines and vaccination programs for elderly persons.
3,572 citations
"Inactivated Influenza Virus Vaccine..." refers background in this paper
...for persons with underlying chronic conditions, kills up to 37,000 persons annually [1, 2]....
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TL;DR: Rates of bronchiolitis-associated hospitalizations associated with RSV infection among infants may be greater than previous estimates for RSV bron chiolitis and pneumonia hospitalizations combined.
Abstract: ContextRespiratory syncytial virus (RSV) causes more lower respiratory tract
infections, often manifested as bronchiolitis, among young children than any
other pathogen. Few national estimates exist of the hospitalizations attributable
to RSV, and recent advances in prophylaxis warrant an update of these estimates.ObjectivesTo describe rates of bronchiolitis-associated hospitalizations and to
estimate current hospitalizations associated with RSV infection.Design and SettingDescriptive analysis of US National Hospital Discharge Survey data from
1980 through 1996.ParticipantsChildren younger than 5 years who were hospitalized in short-stay, nonfederal
hospitals for bronchiolitis.Main Outcome MeasureBronchiolitis-associated hospitalization rates by age and year.ResultsDuring the 17-year study period, an estimated 1.65 million hospitalizations
for bronchiolitis occurred among children younger than 5 years, accounting
for 7.0 million inpatient days. Fifty-seven percent of these hospitalizations
occurred among children younger than 6 months and 81% among those younger
than 1 year. Among children younger than 1 year, annual bronchiolitis hospitalization
rates increased 2.4-fold, from 12.9 per 1000 in 1980 to 31.2 per 1000 in 1996.
During 1988-1996, infant hospitalization rates for bronchiolitis increased
significantly (P for trend <.001), while hospitalization
rates for lower respiratory tract diseases excluding bronchiolitis did not
vary significantly (P for trend = .20). The proportion
of hospitalizations for lower respiratory tract illnesses among children younger
than 1 year associated with bronchiolitis increased from 22.2% in 1980 to
47.4% in 1996; among total hospitalizations, this proportion increased from
5.4% to 16.4%. Averaging bronchiolitis hospitalizations during 1994-1996 and
assuming that RSV was the etiologic agent in 50% to 80% of November through
April hospitalizations, an estimated 51,240 to 81,985 annual bronchiolitis
hospitalizations among children younger than 1 year were related to RSV infection.ConclusionsDuring 1980-1996, rates of hospitalization of infants with bronchiolitis
increased substantially, as did the proportion of total and lower respiratory
tract hospitalizations associated with bronchiolitis. Annual bronchiolitis
hospitalizations associated with RSV infection among infants may be greater
than previous estimates for RSV bronchiolitis and pneumonia hospitalizations
combined.
1,356 citations
"Inactivated Influenza Virus Vaccine..." refers background in this paper
...effect of respiratory syncytial virus (RSV) infection, a frequent cause of lower respiratory illness-related hospitalization among infants and younger children [14]....
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TL;DR: Healthy children younger than one year of age are hospitalized for illness attributable to influenza at rates similar to those for adults at high risk for influenza.
Abstract: Background Despite high annual rates of influenza in children, influenza vaccines are given to children infrequently. We measured the disease burden of influenza in a large cohort of healthy children in the Tennessee Medicaid program who were younger than 15 years of age. Methods We determined the rates of hospitalization for acute cardiopulmonary conditions, outpatient visits, and courses of antibiotics over a period of 19 consecutive years. Using the differences in the rates of these events when influenzavirus was circulating and the rates from November through April when there was no influenza in the community, we calculated morbidity attributable to influenza. There was a total of 2,035,143 person-years of observation. Results During periods when influenzavirus was circulating, the average number of hospitalizations for cardiopulmonary conditions in excess of the expected number was 104 per 10,000 children per year for children younger than 6 months of age, 50 per 10,000 per year for those 6 months to...
1,075 citations
"Inactivated Influenza Virus Vaccine..." refers background in this paper
...These data demonstrate the impact of influenza on high-risk children and on children who are otherwise healthy, and they show that hospitalization rates for influenza in young children are equivalent to or greater than the rates for elderly persons [10, 11]....
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TL;DR: Infants and young children without chronic or serious medical conditions are at increased risk for hospitalization during influenza seasons, and routine influenza vaccination should be considered in these children.
Abstract: Background Young children may be at increased risk for serious complications from influenzavirus infection. However, in population-based studies it has been difficult to separate the effects of influenzavirus from those of respiratory syncytial virus. Respiratory syncytial virus often circulates with influenzaviruses and is the most frequent cause of hospitalization for lower respiratory tract infections in infants and young children. We studied the rates of hospitalization for acute respiratory disease among infants and children during periods when the circulation of influenzaviruses predominated over the circulation of respiratory syncytial virus. Methods For each season from October to May during the period from 1992 to 1997, we used local viral surveillance data to define periods in Washington State and northern California when the circulation of influenzaviruses predominated over that of respiratory syncytial virus. We calculated the rates of hospitalization for acute respiratory disease, excess rate...
1,001 citations