Positive results for GSK's rotavirus vaccine

Separate studies involving GlaxoSmithKline's (GSK) rotavirus vaccine, Rotarix, in Africa and Mexico have shown a reduction in the effects of the virus – a leading cause of diarrhea and severe gastroenteritis in both developed and developing countries.

The papers, both published in the New England Journal of Medicine, showed a 61.2 per cent reduction of the disease in Africa in a placebo controlled study, whereas the Mexican study, which looked at mortality rates after the introduction of the vaccine in 2006, showed a 35 per cent reduction in diarrhea-related child deaths.

The rotavirus is estimated to be responsible for approximately 527,000 deaths each year, according to the World Health Organisation (WHO) with more than 85 per cent of these deaths occurring in low-income countries in Africa and Asia.

In an accompanying editorial piece in the same journal, Dr Mathuram Santosham of Johns Hopkins University welcomed the results of the studies, saying: "Widespread use of these vaccines has the potential to prevent about 2 million deaths over the next decade."

"We now have another powerful weapon to add to our armamentarium to combat deaths from diarrhea — rotavirus vaccines. The vaccines should be introduced immediately in areas with high mortality from rotavirus infection."

The African study involved over 4,900 infants across South Africa and Malawi, examining the effects of Rotarix, with the children split into three equal groups – one receiving three doses of the vaccine, one receiving two doses and a placebo, and one receiving only a placebo.

Vaccine efficacy was lower in Malawi than in South Africa (49.4 per cent vs. 76.9 per cent); however, the number of episodes of severe rotavirus gastroenteritis that were prevented was greater in Malawi than in South Africa (6.7 vs. 4.2 cases prevented per 100 infants vaccinated per year). Efficacy against all-cause severe gastroenteritis was 30.2 per cent.

The Mexican study looked at diarrhea-related deaths in 2008, after setting a baseline in mortality rates from 2003 to 2006 - the four years before the introduction of the Rotarix vaccine. Deaths were found to fall from 18.1 per 100,000 children at the baseline to 11.8 per 100,000 children in 2008.

"Rotavirus disease has caused more than five millions deaths in infants and young children over the last decade," said Thomas Breuer, head of global clinical R&D and chief medical officer of GSK Biologicals. "It is time to act to avoid these unnecessary deaths and hospitalisations from rotavirus gastroenteritis. GSK is committed to working with our partners to help ensure that Rotarix reaches those in need, wherever they live."