Pandemic influenza A(H1N1)pdm09 seroprevalence in Sweden before and after the pandemic and the vaccination campaign in 2009.
PLoS One
; 7(12): e53511, 2012.
Article
em En
| MEDLINE
| ID: mdl-23285299
ABSTRACT
The immunity to pandemic influenza A(H1N1)pdm09 in Sweden before and after the outbreaks in 2009 and 2010 was investigated in a seroepidemiological study. Serum samples were collected at four time points during 2007 (nâ=â1968), in October 2009 (nâ=â2218), in May 2010 (nâ=â2638) and in May 2011 (nâ=â2513) and were tested for hemagglutination inhibition (HI) antibodies. In 2007, 4.9% of the population had pre-existing HI titres ≥40, with the highest prevalence (20.0%) in 15-24 year-olds, followed by ≥80 year-olds (9.3%). The overall prevalence of HI titres ≥40 had not changed significantly in October 2009. In May 2010 the prevalence had increased to 48.6% with the highest percentages in 5-14 year-olds (76.2%) andlowest in 75-79 year-olds (18.3%). One year later the prevalence of HI titres ≥40 had increased further to 52.2%. Children 5-14 years had the highest incidence of infection and vaccine uptake as well as the highest post-pandemic protective antibody levels. In contrast, the elderly had high vaccine uptake and low attack rate but low levels of protective antibodies, underlining that factors other than HI antibodies are involved in protection against influenza A(H1N1)pdm09. However, for all age-groups the seroprevalence was stable or increasing between 2010 and 2011, indicating that both vaccine- and infection-induced antibodies were long-lived.
Texto completo:
1
Base de dados:
MEDLINE
Assunto principal:
Vacinação em Massa
/
Influenza Humana
/
Vírus da Influenza A Subtipo H1N1
Tipo de estudo:
Risk_factors_studies
Limite:
Adolescent
/
Adult
/
Aged
/
Child
/
Child, preschool
/
Female
/
Humans
/
Infant
/
Male
/
Middle aged
País como assunto:
Europa
Idioma:
En
Ano de publicação:
2012
Tipo de documento:
Article