tetano
Editor, Senior Moderator
Clin Infect Dis. 2010 Nov 10. [Epub ahead of print]
Protective Efficacy of Seasonal Influenza Vaccination against Seasonal and Pandemic Influenza Virus Infection during 2009 in Hong Kong.
Cowling BJ, Ng S, Ma ES, Cheng CK, Wai W, Fang VJ, Chan KH, Ip DK, Chiu SS, Peiris JS, Leung GM.
Infectious Disease Epidemiology Group, School of Public Health, Li Ka Shing Faculty of Medicine, Departments of 2Microbiology and 3Pediatrics and Adolescent Medicine, The University of Hong Kong, and 4HKU-Pasteur Research Centre, Hong Kong Special Administrative Region, China.
Abstract
Background. The relationship between seasonal influenza vaccine and susceptibility to 2009 pandemic A/H1N1 virus infection is not fully understood. Methods. One child 6-15 years of age from each of 119 households was randomized to receive 1 dose of inactivated trivalent seasonal influenza vaccine (TIV) or saline placebo in November 2008. Serum samples were collected from study subjects and their household contacts before and 1 month after vaccination (December 2008), after winter (April 2009) and summer influenza (September-October 2009) seasons. Seasonal and pandemic influenza were confirmed by serum hemagglutinination inhibition, viral neutralization titers, and reverse-transcription polymerase chain reaction performed on nasal and throat swab samples collected during illness episodes. Results. TIV recipients had lower rates of serologically confirmed seasonal A/H1N1 infection (TIV group, 8%; placebo group, 21%; [Formula: see text]) and A/H3N2 infection (7% vs 12%; [Formula: see text]), but higher rates of pandemic A/H1N1 infection (32% vs 17%; [Formula: see text]). In multivariable analysis, those infected with seasonal influenza A during the study had a lower risk of laboratory-confirmed pandemic A/H1N1 infection (adjusted odds ratio [OR], 0.35; 95% confidence interval [CI], 0.14-0.87), and receipt of seasonal TIV was unassociated with risk of pandemic A/H1N1 infection (adjusted OR, 1.11; 95% CI, 0.54-2.26). Conclusions. TIV protected against strain-matched infection in children. Seasonal influenza infection appeared to confer cross-protection against pandemic influenza. Whether prior seasonal influenza vaccination affects the risk of infection with the pandemic strain requires additional study. Clinical trials registration. ClinicalTrials.gov number NCT00792051 .
http://www.ncbi.nlm.nih.gov/pubmed/21067351
PMID: 21067351 [PubMed - as supplied by publisher]
Protective Efficacy of Seasonal Influenza Vaccination against Seasonal and Pandemic Influenza Virus Infection during 2009 in Hong Kong.
Cowling BJ, Ng S, Ma ES, Cheng CK, Wai W, Fang VJ, Chan KH, Ip DK, Chiu SS, Peiris JS, Leung GM.
Infectious Disease Epidemiology Group, School of Public Health, Li Ka Shing Faculty of Medicine, Departments of 2Microbiology and 3Pediatrics and Adolescent Medicine, The University of Hong Kong, and 4HKU-Pasteur Research Centre, Hong Kong Special Administrative Region, China.
Abstract
Background. The relationship between seasonal influenza vaccine and susceptibility to 2009 pandemic A/H1N1 virus infection is not fully understood. Methods. One child 6-15 years of age from each of 119 households was randomized to receive 1 dose of inactivated trivalent seasonal influenza vaccine (TIV) or saline placebo in November 2008. Serum samples were collected from study subjects and their household contacts before and 1 month after vaccination (December 2008), after winter (April 2009) and summer influenza (September-October 2009) seasons. Seasonal and pandemic influenza were confirmed by serum hemagglutinination inhibition, viral neutralization titers, and reverse-transcription polymerase chain reaction performed on nasal and throat swab samples collected during illness episodes. Results. TIV recipients had lower rates of serologically confirmed seasonal A/H1N1 infection (TIV group, 8%; placebo group, 21%; [Formula: see text]) and A/H3N2 infection (7% vs 12%; [Formula: see text]), but higher rates of pandemic A/H1N1 infection (32% vs 17%; [Formula: see text]). In multivariable analysis, those infected with seasonal influenza A during the study had a lower risk of laboratory-confirmed pandemic A/H1N1 infection (adjusted odds ratio [OR], 0.35; 95% confidence interval [CI], 0.14-0.87), and receipt of seasonal TIV was unassociated with risk of pandemic A/H1N1 infection (adjusted OR, 1.11; 95% CI, 0.54-2.26). Conclusions. TIV protected against strain-matched infection in children. Seasonal influenza infection appeared to confer cross-protection against pandemic influenza. Whether prior seasonal influenza vaccination affects the risk of infection with the pandemic strain requires additional study. Clinical trials registration. ClinicalTrials.gov number NCT00792051 .
http://www.ncbi.nlm.nih.gov/pubmed/21067351
PMID: 21067351 [PubMed - as supplied by publisher]