Value of immunogenicity studies of influenza vaccine in resource-limited settings
Authors: Thushan I de Silva, Beate Kampmann
Journal: The Lancet Global Health (2017)

The studies1Victor JC Lewis KDC Diallo A et al.Efficacy of Russian-backbone live attenuated influenza vaccine among children in Senegal: a randomised, double-blind, placebo-controlled trial.Lancet Glob Health. 2016; 4: e955-e965Summary Full Text Full Text PDF PubMed Scopus (43) Google Scholar, 2Brooks WA Zaman K Lewis KDC et al.Efficacy of Russian-backbone live attenuated influenza vaccine among young children in Bangladesh: a randomised, double-blind, placebo-controlled trial.Lancet Glob Health. 2016; 4: e946-e954Summary Full Text Full Text PDF PubMed Scopus (41) Google Scholar of Russian-backbone live attenuated influenza vaccine (LAIV) in children from Senegal and Bangladesh in The Lancet Global Health are welcome, in view of the high burden of influenza-associated morbidity and mortality in resource-limited settings. Although the lack of immunogenicity data is highlighted as a limitation by the authors, we feel that the importance of generating such data in future studies is underplayed. With the exception of one study3Bracco Neto H Farhat CK Tregnaghi MW et al.Efficacy and safety of 1 and 2 doses of live attenuated influenza vaccine in vaccine-naive children.Pediatr Infect Dis J. 2009; 28: 365-371Crossref PubMed Scopus (90) Google Scholar including children from South Africa, to our knowledge, no paediatric immunogenicity data exist from sub-Saharan Africa for the Ann Arbor-based LAIV. This amounts to a significant gap in knowledge of how an intranasal LAIV performs immunologically in these settings. Parallels can be drawn with the well-described poorer performance of live oral vaccines in resource-limited settings. The lack of a single identified correlate of protection for LAIV should not deter future immunogenicity studies in resource-limited settings, especially using systems vaccinology approaches designed to dissect the complex interplay of innate and adaptive pathways following vaccination.4Nakaya HI Wrammert J Lee EK et al.Systems biology of vaccination for seasonal influenza in humans.Nat Immunol. 2011; 12: 786-795Crossref PubMed Scopus (593) Google Scholar John C Victor1Victor JC Lewis KDC Diallo A et al.Efficacy of Russian-backbone live attenuated influenza vaccine among children in Senegal: a randomised, double-blind, placebo-controlled trial.Lancet Glob Health. 2016; 4: e955-e965Summary Full Text Full Text PDF PubMed Scopus (43) Google Scholar and colleagues propose that differences in nasopharyngeal ecology could explain differential LAIV performance. As methods to interrogate and integrate complex datasets evolve, testing such hypotheses becomes increasingly possible. Although further efficacy studies of this vaccine in resource-limited settings are vital, in our view, studies probing more mechanistic aspects of LAIV performance are also crucial. Not only might such studies offer some explanation for the lack of efficacy seen in Senegal, but they might also underpin the design of future generations of LAIV for use in resource-limited settings. We declare no competing interests. Efficacy of a Russian-backbone live attenuated influenza vaccine among children in Senegal: a randomised, double-blind, placebo-controlled trialLive attenuated influenza vaccine was well tolerated in young children in Senegal, but did not provide protection against influenza. Further study in such populations, which might experience extended periods of influenza circulation, is warranted. Full-Text PDF Open AccessEfficacy of a Russian-backbone live attenuated influenza vaccine among young children in Bangladesh: a randomised, double-blind, placebo-controlled trialThis single-dose Russian-backbone LAIV was safe and efficacious at preventing symptomatic laboratory-confirmed influenza illness due to vaccine-matched strains. LAIV programmes might reduce the burden of influenza illness in Bangladesh. Full-Text PDF Open Access