The Lancet
Dec 04, 2010  Volume 376 Number 9756 Pages 1873 – 1958
http://www.thelancet.com/journals/lancet/issue/current

Correspondence
Rotavirus vaccine efficacy in African and Asian countries
Stephen Obaro

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The report by George Armah and colleagues (Aug 21, p 606)1 on the efficacy of a pentavalent rotavirus vaccine in sub-Saharan Africa is encouraging news for the control of rotavirus gastroenteritis in African children. Interestingly, the same vaccine is about 50% less efficacious than reported in some developed countries.2 Although the absolute proportion of severe diarrhoeal disease prevented is still much higher in the African setting, the relative poor performance of enteric vaccines in these populations deserves further mechanistic study.

Rotavirus vaccine efficacy in African and Asian countries
Giorgio Tamburlini, Adriano Cattaneo, Lorenzo Monasta
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The design of the studies by George Armah and colleagues1 and K Zaman and colleagues2 on the efficacy of pentavalent rotavirus vaccine against severe rotavirus gastroenteritis in African and Asian countries neglects a crucial factor: breastfeeding.

Rotavirus vaccine efficacy in African and Asian countries – Authors’ reply
Robert F Breiman, George Armah, K Zaman, Samba Sow, Dang Duc Anh, Max Ciarlet, Kathleen M Neuzil
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The pentavalent rotavirus vaccine offers an opportunity to affect child health positively, particularly in regions of the world with high diarrhoea morbidity and mortality. Although our study focused on the prevention of severe gastroenteritis, we agree with Stephen Obaro that the vaccine might be effective against less common outcomes, including mortality. In fact, such an effect has been shown in postmarketing studies, most notably in Mexico, where introduction of a rotavirus vaccine into the national immunisation programme correlated with a significant reduction in all-cause diarrhoea mortality.