FRANK JORDANS Associated Press Writer GENEVA (AP) — The World Health Organization on Friday recommended universal vaccination against the rotavirus, a leading cause of diarrhea which kills more than 500,000 children worldwide each year. The vaccine is already a common part of national immunization programs in Europe and the Americas. WHO extended its advice to developing countries, saying it can be used as effectively there as in rich nations. More than 85 percent of all diarrhea deaths occur in Africa and Asia, where patchy medical coverage means children with severe cases often don’t receive rehydration treatment in time to survive. The Seattle-based Program for Appropriate Technology in Health estimates that vaccination can prevent 225,000 child deaths in the developing world each year. Poor countries will be able to apply for funding from the Global Alliance for Vaccines and Immunization to help them buy the vaccine, said spokeswoman Ariane Leroy. The group, which includes governments and private entities such as the Bill and Melinda Gates Foundation, has already pledged to make $4 billion available to developing countries until the end of 2015 — most of it for vaccine programs. “It’s very good that the rotavirus vaccine is now recommended for all regions. It’s a vaccine that has potential to save many lives,” said Tido von Schoen-Angerer of Medecins Sans Frontieres. The group also known as Doctors Without Borders campaigns for universal access to essential medicines. Dr. Paul Offit, chief of infectious diseases at the Children’s Hospital of Philadelphia and the co-inventor of one rotavirus vaccine manufactured by Merck & Co., said immunizing half the children in the United States has reduced the incidence of disease by 80 to 90 percent. Merck’s RotaTeq and rival GlaxoSmithKline PLC’s Rotarix are administered orally in the first six months after birth. Von Schoen-Angerer said one of the challenges would now be getting the drug to children in that period. “In areas where the regular vaccine program doesn’t function well, that might be difficult.” WHO already recommends universal vaccination against tuberculosis; diphtheria; tetanus; whooping cough; haemophilus influenzae type B, or Hib, which can cause meningitis and pneumonia; hepatitis B; human papillomavirus; the pneumococcus bacterium; polio; and measles.