Influence of nonpolio enteroviruses and the bacterial gut microbiota on oral poliovirus vaccine response: A study from south India

Background. Oral poliovirus vaccine (OPV) is less immunogenic in low-or middle-income than in high-income countries. We tested whether bacterial and viral components of the intestinal microbiota are associated with this phenomenon. Methods. We assessed the prevalence of enteropathogens using TaqMan array cards 14 days before and at vaccination in 704 Indian infants (aged 6-11 months) receiving monovalent type 3 OPV (CTRI/2014/05/004588). Nonpolio enterovirus (NPEV) serotypes were identifed by means of VP1 sequencing. In 120 infants, the prevaccination bacterial microbiota was characterized using 16S ribosomal RNA sequencing. Results. We detected 56 NPEV serotypes on the day of vaccination. Concurrent NPEVs were associated with a reduction in OPV seroconversion, consistent across species (odds ratio [95% confdence interval], 0.57 [.36-.90], 0.61 [.43-.86], and 0.69 [.41-1.16] for species A, B, and C, respectively). Recently acquired enterovirus infections, detected at vaccination but not 14 days earlier, had a greater interfering effect on monovalent type 3 OPV seroresponse than did persistent infections, with enterovirus detected at both time points (seroconversion in 44 of 127 infants [35%] vs 63 of 129 [49%]; P =.02). Te abundance of specifc bacterial taxa did not differ signifcantly according to OPV response, although the microbiota was more diverse in nonresponders at the time of vaccination. Conclusion. Enteric viruses have a greater impact on OPV response than the bacterial microbiota, with recent enterovirus infections having a greater inhibitory effect than persistent infections. © 2018 The Author(s).