tetano
Editor, Senior Moderator
Clin Infect Dis. 2014 May 13. pii: ciu356. [Epub ahead of print]
Incidence of influenza virus infections in children in Hong Kong in a three year randomised placebo-controlled vaccine study, 2009-12.
Cowling BJ1, Perera RA2, Fang VJ1, Chan KH3, Wai W1, So HC1, Chu DK2, Wong JY1, Shiu EY1, Ng S4, Ip DK5, Peiris JS2, Leung GM5.
Author information
Abstract
BACKGROUND:
School-age children suffer high rates of influenza virus infections and associated illnesses each year, and are a major source of transmission in the community. However, information on the cumulative incidence of infection in specific epidemics is scarce, and there are limited studies with sufficient follow-up to identify the strength and duration of protection against re-infection.
METHODS:
We randomly allocated children 5-17y of age to receive trivalent inactivated influenza vaccine (TIV) or placebo from September 2009 through January 2010, and then conducted follow up for 3 years including regular collection of sera, symptom diaries, and collection of nose and throat swabs during illness episodes in subjects or their household members.
RESULTS:
Of 796 children initially randomized, 484 continued to participate for all three years. In unvaccinated children, cumulative incidence of infection was estimated to be 59% in the first wave of H1N1pdm09 in 2009-10, and 7%, 14%, 20% and 31% in subsequent epidemics of H3N2 (2010), H1N1pdm09 (2011), B (2012) and H3N2 (2012), respectively. Infection with H1N1pdm09 in 2009-10 and H3N2 in 2010 was associated with protection against infection with subsequent epidemics of the same subtype in 2011 and 2012 respectively, but we found no evidence of heterotypic or heterosubtypic protection against infection.
CONCLUSIONS:
We identified substantial incidence of influenza virus infections in children in Hong Kong in 5 major epidemics over a three year period, and evidence of homosubtypic but not heterosubtypic protection following infection.
? The Author 2014. Published by Oxford University Press on behalf of the Infectious Diseases Society of America. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.
PMID:
24825868
[PubMed - as supplied by publisher]
http://www.ncbi.nlm.nih.gov/pubmed/24825868
Incidence of influenza virus infections in children in Hong Kong in a three year randomised placebo-controlled vaccine study, 2009-12.
Cowling BJ1, Perera RA2, Fang VJ1, Chan KH3, Wai W1, So HC1, Chu DK2, Wong JY1, Shiu EY1, Ng S4, Ip DK5, Peiris JS2, Leung GM5.
Author information
Abstract
BACKGROUND:
School-age children suffer high rates of influenza virus infections and associated illnesses each year, and are a major source of transmission in the community. However, information on the cumulative incidence of infection in specific epidemics is scarce, and there are limited studies with sufficient follow-up to identify the strength and duration of protection against re-infection.
METHODS:
We randomly allocated children 5-17y of age to receive trivalent inactivated influenza vaccine (TIV) or placebo from September 2009 through January 2010, and then conducted follow up for 3 years including regular collection of sera, symptom diaries, and collection of nose and throat swabs during illness episodes in subjects or their household members.
RESULTS:
Of 796 children initially randomized, 484 continued to participate for all three years. In unvaccinated children, cumulative incidence of infection was estimated to be 59% in the first wave of H1N1pdm09 in 2009-10, and 7%, 14%, 20% and 31% in subsequent epidemics of H3N2 (2010), H1N1pdm09 (2011), B (2012) and H3N2 (2012), respectively. Infection with H1N1pdm09 in 2009-10 and H3N2 in 2010 was associated with protection against infection with subsequent epidemics of the same subtype in 2011 and 2012 respectively, but we found no evidence of heterotypic or heterosubtypic protection against infection.
CONCLUSIONS:
We identified substantial incidence of influenza virus infections in children in Hong Kong in 5 major epidemics over a three year period, and evidence of homosubtypic but not heterosubtypic protection following infection.
? The Author 2014. Published by Oxford University Press on behalf of the Infectious Diseases Society of America. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.
PMID:
24825868
[PubMed - as supplied by publisher]
http://www.ncbi.nlm.nih.gov/pubmed/24825868