A recent study has described the higher titres of neutralizing antibody in breastmilk samples from women in India and Vietnam, than in the USA and also describes the ability of that breastmilk antibody to neutralize rotavirus [30]. One reason why the ≥3-fold SNA responses to G1 and P1A[8], measured at 14 days PD3, were considerably lower in African subjects who received PRV than in subjects in previous studies could be due to

the presence of rotavirus-specific SNA in these children. It is important high throughput screening compounds to note, that in this study, virtually every subject was breastfed during the entire vaccination period. In the end, the immune responses observed in this study may be a reflection of the population and the associated health and socio-economic conditions. In conclusion, this study has shown that PRV was immunogenic in African infants and that the generated anti-rotavirus IgA seroresponse rate was similar and high in each

of the African sites, but generally much lower than that reported in Europe and USA. The significance of reduced PD3 anti-rotavirus IgA seroresponse rate and GMT levels in African infants, when selleck chemicals compared to similar studies in developed countries, is still not well Bay 11-7085 understood and further studies are needed to throw more light on this observation. An implication of the observed early exposure to natural rotavirus infection in African infants in this study is that vaccination should be scheduled as early as possible to make it more useful, and thus, evaluation of a birth dose of vaccine might be warranted. Additional studies are

required to understand how we could better utilize live oral rotavirus vaccines in developing country populations where the disease burden is so high. These studies could evaluate alternative immunization schedules both earlier (birth, 1 month and 2 months) to address early acquisition of infection, but also later schedules (2, 3, 4 months) to avoid potential interference of maternal antibody. It is clear that we need to better understand the role of maternal antibody in rotavirus vaccine “take”. Other proposed studies include the need for a booster dose of vaccine, assessing the role of breast milk antibody, and the potential for micro-supplementation at the time of vaccination to improve immunogenicity. The trial (Merck protocol V260-015) was funded by PATH’s Rotavirus Vaccine Program (RVP) with a grant from the GAVI Alliance and the trial was co-sponsored by Merck & Co., Inc.