LONDON: Combining two types of polio vaccine, including one that is injected rather than given orally, appears to give better immunity and to eradicate the crippling disease.
British and Indian researchers said the inactivated polio vaccine (IPV), which is given by injection, could provide better and long lasting protection used live oral polio vaccine (OPV).
Africa and Europe over the last 10 years have efforts to wipe out the disease, caused by a virus that replicates in the gut and can be passed on through contact with infected faeces.
Polio invades the nervous system and can cause irreversible paralysis, within hours and the World Health Organisation’s repeated warning is that as long as any child remains infected with polio, children everywhere are at risk.
Most vaccination campaigns, including emergency ones that were started last year covering 20 million children in Syria and neighbouring countries, use multiple doses of OPV.
“Because IPV is injected into the arm, rather than taken orally, it’s been assumed it doesn’t provide much protection in the gut and so would be less effective at preventing faecal transmission than OPV,”
Jacob John, said as an associate professor at the India’s Christian Medical College.
He study and research which covered 450 children from a densely populated urban area in Vellore, India, found that where they already had a level of immunity due to OPV, the injected vaccine actually boosted their gut immunity.
Polio re-emerged in Syria in 2013 for the first time in 14 years, fanning fears of a wider international spread and prompting a vast regional emergency vaccination campaign.
Children in unsanitary conditions are particularly vulnerable to infection with the polio virus, which can spread through food and water.
Although, polio has been declining substantially in endemic areas since 2012, around 10 countries are currently considered to have active polio transmission.
Polio is still endemic in three of these countries Afghanistan, Pakistan and Nigeria - and the remainder are countries that were once polio-free but have been re-infected.
Jacob John’s team working with researchers at Imperial College London, had all received OPV, standard vaccination programmes.
Half of the children were given a dose of the injected IPV vaccine and half given nothing, and a month later, the children were given a “challenge” dose of the live oral vaccine to simulate re-infection.
The injected vaccine is more effective at boosting immunity against infection than the oral vaccine alone. IPV could be used to boost immunity in people travelling from or to polio-infected countries, such as Afghanistan, Pakistan and Nigeria.
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