Rotavirus Strain Distribution before and after Introducing Rotavirus Vaccine in India.

Tintu Varghese,Jacqueline E Tate,Seshadri Venkatasubramanian,Mrutunjay Dash,Prasantajyoti Mohanty,Nirmal K Mohakud,Sidhartha Giri,Chethrapilly Purushothaman Girish Kumar,Rashmi Arora,Gagandeep Kang,Manohar Badur,Sanjeev Chaudhury,Venkata Raghava Mohan,Shayam Kaushik,Shainey Alokit Khakha,Geeta Gathwala,Nayana P Nair,Umesh D Parashar,Rajib K Ray

doi:10.3390/pathogens10040416

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.

Highlights

Rotavirus is the leading etiology of acute gastroenteritis in children under 5 years old worldwide, causing high mortality, especially in middle- and low-income countries.India accounts for 22% of the total global rotavirus mortality [1]
The maximum reduction in rotavirus diarrhea was seen in Tirupati (72.1%), the site with maximum vaccine coverage, compared to a 32.5% reduction in Vellore, which was the last to introduce the Pathogens 2021, 10, x FOR PEER REVIEW
The overall prevalence of rotavirus in children with hospitalized gastroenteritis decreased after vaccine introduction, reaching

Summary

Introduction

Rotavirus is the leading etiology of acute gastroenteritis in children under 5 years old worldwide, causing high mortality, especially in middle- and low-income countries. These rotavirus vaccines differ in their genotypic composition, with Rotarix and Rotavac being the monovalent vaccines and RotaTeq and Rotasiil being the pentavalent vaccines [4]. Rotarix and RotaTeq vaccines have been available on the market since 2006 and are currently used by nearly 90 countries in their immunization programs [4]. The emergence of G9P[8] and G12P[8] was reported with the use of the RotaTeq vaccine [8] Such changes were observed in other countries without rotavirus vaccination [9,10].

Prevalence of Rotavirus Diarrhea

Rotavirus Genotype Distribution in India

Discussion

Study Sites

Sample Collection and Laboratory Testing