Rotavirus Strain Distribution before and after Introducing Rotavirus Vaccine in India

Abstract

In April 2016, an indigenous monovalent rotavirus vaccine (Rotavac) was introduced to the National Immunization Program in India. Hospital-based surveillance for acute gastroenteritis was conducted in five sentinel sites from 2012 to 2020 to monitor the vaccine impact on various genotypes and the reduction in rotavirus positivity at each site. Stool samples collected from children under 5 years of age hospitalized with diarrhea were tested for group A rotavirus using a commercial enzyme immunoassay, and rotavirus strains were characterized by RT-PCR. The proportion of diarrhea hospitalizations attributable to rotavirus at the five sites declined from a range of 56–29.4% in pre-vaccine years to 34–12% in post-vaccine years. G1P[8] was the predominant strain in the pre-vaccination period, and G3P[8] was the most common in the post-vaccination period. Circulating patterns varied throughout the study period, and increased proportions of mixed genotypes were detected in the post-vaccination phase. Continuous long-term surveillance is essential to understand the diversity and immuno-epidemiological effects of rotavirus vaccination.

Molecular Epidemiology of Rotavirus Strains in Symptomatic and Asymptomatic Children in Manhiça District, Southern Mozambique 2008–2019

“…These results in our MSD cases are similar to those previously found in hospital-based studies in Mozambique, which also reported G3P [8] as the most frequent combination in MSD [18]. In addition, G3P [8] was also recorded as the most frequent combination in the post-vaccine introduction in other countries such as Fiji and India [37,38]. The dynamic change in the diversity of rotavirus genotypes, we observed in the post-vaccine introduction period in our study, may not explain whether this change is related to vaccine introduction in Mozambique, because genotypes shifting may occur in countries regardless of the implementation or not of vaccine into immunization programs, demonstrating a fluctuation of genotypes within and between countries [39].…”

Rotaviruses and Rotavirus Vaccines

“…G1P [8] was the predominant genotyped reported in the pre-vaccination period, whereas G3P [8] became the dominant genotype in the post-vaccination period. Geographic variation in genotype distribution was noted between northern and southern sites [33].…”

“…Castells et al reported detection of rotavirus in calves reared for beef and dairy production in Uruguay [24]. Multiple genotypes associated with bovine disease were detected including G6P [11] (40.4%), G6P [5] (38.6%), G10P [11] (19.3%), as well as the uncommon genotype G24P [33] (1.8%) [24].…”

Rotaviruses and Rotavirus Vaccines

“…Long-term surveillance pre- and post-vaccine introduction was also conducted at five sentinel sites in India between 2012 to 2020 by Varghese and colleagues [ 33 ]. The Rotavac vaccine was introduced in 2016 resulting in a decrease in rotavirus-associated hospitalisations.…”

“…G1P[8] was the predominant genotyped reported in the pre-vaccination period, whereas G3P[8] became the dominant genotype in the post-vaccination period. Geographic variation in genotype distribution was noted between northern and southern sites [ 33 ].…”