Rotavirus: Preventive Vaccines and a Rare Side Effect

Rotaviruses are the most common cause of diarrhoeal disease among infants. Till now 108 countries have introduced rotavirus vaccines to prevent severe diarrhea. The Global Rotavirus Surveillance Network (GRSN) was established by WHO in 2008. Some studies reported that rotavirus vaccination can lead to a small increase in the risk of intussusception, a type of bowel blockage. This is a rare side effect. Intussusception, death of tissue of the intestinal wall due to lack of blood supply may cause life-threatening complications if left untreated. In infants idiopathic ileocolic intussusception is the most common form typically managed with operative or non operative reduction like hydrostatic or pneumatic enemas. Whereas, in adults and older children, intussusception is not very common and occurs more often in the colon of small intestine, pathogenesis is lead point in most of the symptomatic cases. Numerous countries have scrupulously noted the occurrence of intussusception post vaccination, and others yet to introduce the vaccine are gathering base line data on the incidence of intussusception which is an important safety issue in determining vaccine policy. However, it should be noted that naturally occurring intussusception, although rare, does occur in the very young. Due to heavy burden of rotavirus, some developing countries have introduced rotavirus vaccines. In India it is now part of the national immunization programme. Hospitalizations and deaths from rotavirus have been averted significantly because vaccination far exceeded the reported cases of intussusception with vaccination. The underlying rationale behind the differing risk of intussusception after rotavirus vaccination in various countries is not yet determined, therefore continuous monitoring is necessary.