Vaccine Effectiveness Against Medically Attended, Laboratory-Confirmed Influenza Among Children Aged 6 to 59 Months, 2003–2004

Abstract

Full vaccination provided measurable protection against laboratory-confirmed influenza among children who were aged 6 to 59 months during a season with suboptimal vaccine match. No vaccine effectiveness was identified with partial vaccination among children who were aged 6 to 23 months, affirming that children need to be fully vaccinated to obtain protective effects. These results strengthen the evidence of the vaccine's ability to reduce substantially the burden of disease in this age group.

2012/13 influenza vaccine effectiveness against hospitalised influenza A(H1N1)pdm09, A(H3N2) and B: estimates from a European network of hospitals

“…[153,156,157] Several observational studies of TIV VE among children less than 5 years of age have found a VE of 60-85% in seasons where vaccine strains are well-matched to circulating strains, but a VE of 0-60% when vaccines are poorly matched to circulating strains. [158][159][160][161][162][163][164] In addition to the direct protection of children conferred by influenza immunization, limited data indicate that protection of unvaccinated household [165,166] and community contacts [154] may be conferred by immunization of children.…”

“…[167][168][169] Observational studies have demonstrated that children who had not previously received vaccine and who received only one dose of vaccine had no statistically significant protection while children who received two doses had significant protection. [159,163,170,171] As a result of these data, all children aged 6 months to 8 years who are being vaccinated for the first time should receive 2 vaccine doses separated by ≥4 weeks. Once a child has been primed, either with vaccine or natural infection, a single dose of vaccine should elicit protective antibodies.…”

Surveillance of influenza A H1N1 2009 among school children during 2009 and 2010 in São Paulo, Brazil

“…The recent CDC influenza vaccination recommendations extended protection to the entire population after the pandemic first wave to reduce overall influenza infection rates 11 .…”

Vaccine effectiveness against laboratory-confirmed influenza in infants: A matched case control study

“…The few published studies that have evaluated influenza vaccine in children less than 24 months of age have estimated the vaccine efficacy/effectiveness to range from -7% up to 52%, depending on a variety of factors including the outcome measured, the particular influenza season, and the number of vaccine doses. 16,17 In contrast, studies of the effectiveness of influenza vaccination among older children premature birth and low birth weight, routine infant immunization status and influenza vaccination status. Overall, asthma or reactive airway disease (documented on at least two separate occasions) accounted for 41% of chronic illnesses.…”