An update on the current and future management of rotavirus in India

More than 110 million children in India aged younger than 5 years have diarrhea, with an average of 3.2 episodes a year. It’s estimated that 7% to 8% of community-based episodes are due to rotavirus—a total of 25 million to 28 million episodes in young children a year, according to a review article published recently in the Indian Journal of Public Health.

The lack of a national rotavirus vaccination program is at the heart of this public health issue, according to this article and another review published recently in Indian Pediatrics. Both papers note that the prevalent serotypes of rotavirus are different in India, and state that the indigenous vaccines under development may be more effective.

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[/s2If][s2If is_user_logged_in()] diarrhea, and 39% of those deaths are estimated to be due to rotavirus diarrhea, resulting in 84,000 deaths a year, the Indian Journal of Public Health article reported.

Key Point: Rotavirus morbidity and mortality in children under 5 years could be greatly reduced by a national rotavirus vaccine program in India using the 2 vaccines currently on the market. Indigenous vaccines in development may be even more effective at preventing gastroenteritis caused by the rotavirus serotypes prevalent in India. Hygiene and sanitation alone will not prevent rotavirus because of the persistence of the virus on hard surfaces and hands.

In the Indian Pediatrics review article, the authors estimated that an immunization program for rotavirus could prevent up to one-third of rotavirus-related deaths.

“It will be best if measures like hygiene, sanitation, and safe water supply could control it,” the authors of the Indian Journal of Public Health article wrote. However, they noted that the virus is resistant to many disinfectants (although inactivated by chlorine) and survives on hard surfaces, in contaminated water, and on hands. With no specific medication to treat rotavirus, the only other options are a vaccine to prevent it or oral rehydration to prevent deaths, but oral rehydration fails in many cases due to vomiting, resulting in hospitalization for intravenous fluids.

Different strains

Serotype diversity has made indigenous vaccine development a priority. Even though there are 2 vaccines on the market—RotaTeq and Rotarix—new strains mean the need for continued surveillance. Indigenous vaccines will be more effective in India, where G2P[4] and G1P[8] are the main serotypes, constituting almost half of all cases, the authors wrote. There are also unusual serotypes such as G9P[8], G1P[6], G2P[6], G2P[8], G9P[4], and G9P[6]; these are not prevalent elsewhere in the world. There are also differences in India in the North, South, East, and West.

The authors stated that based on serotype-specific immunity, RotaTeq will protect against only 48.1% of cases of rotavirus diarrhea in India. Rotarix may provide protection against strains with different serotypes but has cross-reactive antigens.

Trials done for both RotaTeq and Rotarix have variable results in terms of efficacy and seroconversion in developed and developing countries. A recent trial in India found a seroconversion rate of 58.3% after 2 doses of Rotarix, which is low compared with trials in developed countries.

In Malawi, the efficacy of Rotarix against severe rotavirus gastroenteritis was 50%. For this reason, the World Health Organization (WHO) recommends 3 doses. In addition, WHO recommends that a vaccine with 60% efficacy may be given because it will save lives.

Indigenous vaccine

Indian vaccine manufacturers are working on an indigenous vaccine. Bharat Biotech International, Biological E. Ltd., Shantha Biotechnic, and Serum Institute of India are working on a technology transfer arrangement with the United States National Institutes of Health (NIH) to develop a vaccine; Bharat Biotech’s rotavirus vaccine is in phase 3 human studies. Called 116E, it is based on serotype G9P[11].

The Indian Pediatrics article noted that rotavirus diarrhea is typically measured in terms of hospitalizations; on average, 34% of diarrhea hospitalizations are caused by rotavirus infections. The proportion of severe diarrhea due to rotavirus has gone up, from 25% in studies completed before 2000 to more than 38% in studies completed after 2005, which parallels a global increase.

As sanitation and hygiene improve, other bacteria and parasites that cause gastroenteritis are being reduced, so that the more persistent rotavirus becomes a higher proportion of total gastroenteritis cases, the researchers noted.

Efficacy data from India are not yet available on Rotarix or RotaTeq, the authors said, but both have been tested and this can “predict the efficacy likely to be seen in India.”

A national rotavirus vaccination program could prevent an estimated 27,000 to 44,000 deaths a year in India in children under 5 years, and it could prevent 1 case of severe gastroenteritis for every 11 children immunized, the authors estimated. One of the problems, they noted, is the relatively low proportion of children who receive any routine immunizations, or the final doses. “Improving the overall performance of the immunization system is critical to the success of any vaccine introduction,” the authors stated.

As India awaits the results of field trials of indigenously developed vaccines, there also are concerns about affordability, the authors stated. “Cost consideration will also be important as the country requires about 100 million doses every year for a 3-dose schedule,” they wrote.

In the Indian Journal of Public Health article, the authors wrote that the manufacturer of one of the indigenous vaccines in development, Bharat Biotech, has stated that the vaccine price would be $1.00 per dose. With an incremental cost effectiveness ratio of $21.41 to $34.00 per disability-adjusted life year, this “satisfies the WHO criterion for a cost-effective intervention,” the authors wrote. They emphasized that rotavirus vaccinations should be more widespread now: “Despite the tremendous diversity of rotavirus strains in India, rotavirus vaccines provide cross-protection and have been shown to be effective against both vaccine and nonvaccine strains.”

Sources: Taneja DK, Malik A. Burden of rotavirus in India–is rotavirus vaccine an answer to it? Indian J Public Health. 2012;56(1):17-21.

Kahn G, Fitzwater S, Tate J, et al. Epidemiology and prospects for prevention of rotavirus disease in India. Indian Pediatr. 2012;49(6):467-474.

Access the original journal information here:
http://www.ijph.in/article.asp?issn=0019-557X;year=2012;volume=56;issue=1;spage=17;epage=21;aulast=Taneja
Journal publishers are independent from mdCurrent-India and may require a subscription or charge a fee to download the full article.

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