LONDON (Reuters) - Countries that vaccinate babies against rotavirus, which can cause severe diarrhea and kill in days, have significantly reduced the number of children admitted to hospitals with the disease, a report showed on Thursday.
Data from the United States, Australia, Mexico and El Salvador, where rotavirus vaccines have recently become part of routine childhood immunizations, show steep and swift falls in the number of children under five becoming ill with the virus.
The studies published in a supplement to The Pediatric Infectious Disease Journal, also show large reductions in rotavirus disease among older, unvaccinated children, suggesting that vaccination of babies may also limit the overall amount of virus transmission, giving what is known as "herd immunity."
"In both the developed and developing worlds, we see a rapid and impressive reduction in rotavirus infections following the roll-out of vaccine," Dr. John Wecker, director of the vaccine access and delivery global program at the non-profit organization PATH, said in a statement with the data.
He said these findings should compel policymakers and international donors to support and implement World Health Organization (WHO) recommendations to introduce rotavirus vaccines in all countries as soon as possible.
Diarrhea is one of the top two killers of children under five worldwide, and rotavirus is the leading cause of severe diarrheal disease in children. Each year, rotavirus-related diarrhea kills more than 500,000 children and is the cause of many millions more needing hospital treatment.
Rotavirus vaccines made by various drug firms including GlaxoSmithKline, Merck and Sanofi-Aventis are now part of the regular vaccination schedule for babies in many wealthy and some middle-income countries.
In 2009, the WHO recommended that all countries should include rotavirus vaccines into national vaccination programs, but many developing countries struggle to afford them.
The global vaccines alliance GAVI has committed to help fund rotavirus vaccine introduction in at least 40 of the world's poorest countries by 2015. But the alliance is facing a funding gap of almost $4 billion and is seeking extra donor money to fund these and other vaccines for poorer countries.
"Rotavirus vaccines have enormous potential to save lives, and it is tragic that they are not more widely available to the children who need them most," Helen Evans, GAVI's interim chief executive, said in a statement. "We urgently need to get these life-saving vaccines to children in developing countries."
The studies showed that in Mexico, which introduced the shots as part of regular childhood immunizations in May 2007, there was a 40 percent decline in hospitalizations of children under five during the 2009 rotavirus season.
In Australia, which introduced rotavirus vaccine in July 2007, there was a 89-94 percent reduction in the two years after vaccine introduction, and in the United States, there was a 58-86 percent reduction over the three years following vaccine introduction in July 2006.
In El Salvador, rotavirus hospitalization rates for under fives fell by 69-81 percent in the two and a half years following introduction of the vaccine in October 2006.
(Editing by Janet Lawrence)