Incidence varied greatly by geography with the highest rate ultrasound-detected intussusception of 581 per 100,000 child-years detected in the south (Vellore) and the lowest rate of 28 per 100,000 child-years detected in the north (Delhi). Approximately half (52%) of the intussusceptions were transient

and none required surgery. No cases occurred within 28 days of vaccination and no children died. The initial clinical trial results for the indigenously produced rotavirus vaccine, Rotavac, showed that the vaccine was 56% effective against severe rotavirus gastroenteritis during the first year of life which is comparable to the GDC0199 efficacy of the other internationally available vaccines in developing country settings [1], [33], [34] and [35]. In a follow-up analysis, the vaccine efficacy was shown to be sustained through the second year of life with an efficacy of VE-822 in vivo 49% in the second year of life unlike the other available vaccines which showed

a substantially reduced efficacy during the second year of life in some developing country settings [36]. The vaccine provided comparable protection against a wide variety of strains. Forty infants would need to be vaccinated to prevent a severe episode of rotavirus gastroenteritis and 21 infants would need to be vaccinated to prevent an episode of rotavirus gastroenteritis of any severity. There are additional oral rotavirus vaccines in the pipeline in India (Table 1). One such vaccine is an oral bovine rotavirus pentavalent vaccine (BRV-PV) containing Montelukast Sodium bovine-human reassortant strains of serotype G1, G2, G3, G4, and G9 that has been developed by the Serum Institute of India, Ltd. in collaboration

National Institutes of Health (NIH) in the United States [37]. This vaccine has completed animal toxicity studies and Phase I and II clinical trials in adults, toddlers, and infants and was found to be safe and immunogenic. Seroconversion rates were similar to those reported for Rotarix in India. Phase III trials to assess its efficacy against severe rotavirus gastroenteritis are planned. Another bovine human reassortant vaccine under development by Shantha Biotechnics Limited based on the National Institutes of Health’s bovine-human reassortant strains [38]. This oral bovine human reassortant tetravalent vaccine (BRV-TV) expresses serotypes G1, G2, G3, and G4. In Phase I/II clinical trials, all three concentrations of antigen tested were immunogenic and resulted in an increase in anti-rotavirus IgA antibodies. The vaccine arm with the highest concentration of antigen had the highest sero-response rate and also exceeded that of the RotaTeq arm.