Oral polio vaccine remains tool of choice in eradication
By Wayne Hearn
Rotary International News - 11 October 2007
Oral polio vaccine.
Photo by Rotary Images
Rotary and its spearheading partners in the Global Polio Eradication Initiative remain committed to reaching all children with the oral polio vaccine (OPV).
Experts with the World Health Organization (WHO) say a recently reported outbreak of vaccine-derived polio in northern Nigeria is an extremely rare occurrence that happens when the weakened form of the virus used in the oral vaccine mutates to a point where it regains its ability to spread and to paralyze children. Such outbreaks are most likely to occur in communities with low childhood immunization rates and poor sanitation, circumstances that give the virus more opportunities to mutate as it circulates among unprotected children.
“Some recent media reports have been misinterpreted as implying that oral polio vaccine has paralyzed 69 children in northern Nigeria,” WHO says in a statement. “In fact, these children were paralyzed by a vaccine-derived poliovirus to which they were vulnerable because they were not sufficiently vaccinated.”
“This is a reflection of low vaccine coverage in this part of Nigeria,” explains Dr. David Heymann, WHO’s representative of the director-general for polio eradication. He notes that of the children paralyzed, 60 were either unvaccinated or insufficiently vaccinated.
“The only solution is to step up our efforts to immunize all of Nigeria’s children,” says Robert S. Scott, chair of The Rotary Foundation Trustees and the International PolioPlus Committee. “It would be tragic if parents kept their children from receiving the vaccine based on unwarranted fears about its safety. OPV is the best, most effective weapon we have to fight our real enemy: the wild poliovirus.”
According to WHO, “only OPV is proven to rapidly provide very high immunity in the (human) gut and stop polio transmission in a tropical, developing-country setting.”
Nigeria is one of only four countries where spread of the wild poliovirus has not been stopped. Since the outbreak was identified in August 2006, four mass immunization campaigns have been completed, and more are scheduled.
For more information, please see Rotary's official statement.