Polio: Two vaccines are better than one

double polio vaccine

New research suggests using an oral and injected polio vaccine could boost eradication efforts.

New research suggests using two types of polio vaccine is more effective than using just one. The research team found administering an injection of the inactivated polio virus (IPV) alongside the oral dose of activated poliovirus vaccine (OPV) boosts patients’ immunity. It’s hoped the findings could help speed up the eradication of polio.

Currently, the oral vaccine is leading the battle against polio but this new research from India may change the way we fight the virus. The findings, which World Health Organisation calls “truly historic”, will potentially lead to a total eradication of the disease which is now widespread in only three countries.

Fighting polio has been one of the greatest global health success stories. As recently as 1988 there were 350,000 cases of polio in 125 countries. Once the worldwide vaccination programme was launched in 1988, the number of cases fell dramatically to just 291 in 2012. Polio is currently widespread in only three countries – Nigeria, Pakistan, and Afghanistan.

The disease is spread through contact with infected faeces and the oral vaccine is currently the preferred prevention method as it’s cheap and protects digestive tract from lower transmission of the virus. The injected vaccine works largely in the bloodstream. However, the protection offered by the oral vaccine wanes over time, so repeated doses are needed.

In this latest study, reported in Science Magazine, doctors tested the two vaccines on 1,000 children in northern India. The use of both types of vaccine lowered transmission and infection. “They both have an important role to play in the eradication programme,” said Professor Nick Grassly, co-author of the study.

The use of the IPV is more effective as a booster than multiple doses of the OPV, according to the study. However, the biggest challenge facing health workers, is not which vaccine to use, but accessing children in conflict zones.

In the last year war-torn Syria has seen an re-emergence of polio as health workers are prevented from administering the vaccine to children due to the dangerous situation. Polio from Syria has also spread across the border into Iraq. In addition, aid workers administering vaccines in Pakistan and Nigeria have come under attack from militant groups who suspect them of spying, with many being killed in recent years.

“This study has revolutionised our understanding of inactivated polio vaccine and how to use it in the global eradication effort to ensure children receive the best and quickest protection possible from this disease,” said Dr. Bruce Aylward, the World Health Organisation’s assistant director general for polio.