Prequalification certifies that the vaccine meets international standards for quality and safety.   That allows United Nations agencies such as UNICEF to buy and distribute it for immunization campaigns.  The new vaccine shot is designed to be more genetically stable than older oral polio vaccines, lowering the risk of triggering new  outbreaks while helping to stop transmission.  The move follows a pledge by global leaders in December to provide $1.9 billion to support eradication efforts.  The WHO said 370 million children will benefit from the vaccine.

–Reuters–