FRIDAY, July 11, 2014 (HealthDay News) -- Polio is history in much of the world, but remains common in places like Afghanistan, Nigeria and Pakistan. Giving vaccinated children an extra dose of inactivated polio vaccine could boost their immunity and help eradicate the highly infectious disease, a new study suggests.
Although the polio vaccine is highly effective, immunity wanes as early as a year after vaccination. Vaccinated children and adults can still be infected and contribute to the spread of the disease, according to background information in the study, published July 10 in The Lancet.
The new findings suggest that giving an inactivated polio vaccine dose to young children who have already received oral polio vaccine may help speed up eradication of polio worldwide, said study lead author Dr. Jacob John, of Christian Medical College in India.
To assess this approach, researchers gave a dose of inactivated polio vaccine to 225 children, ages 1 to 4, in India. All had received at least five doses of oral polio vaccine as part of routine immunization at least six months earlier. Another 225 children received no additional vaccine.
The children who received the additional dose of inactivated polio vaccine showed stronger immune system response against the polio virus than those who did not receive the additional dose, the study authors said in a journal news release.
While giving an additional dose of polio vaccine may boost immunity in previously vaccinated children, the impact on the wider population and the cost-effectiveness of an extra dose remain uncertain, Kimberly Thompson, a professor at the University of Central Florida College of Medicine, wrote in an accompanying journal editorial.
The U.S. Centers for Disease Control and Prevention has more about polio.