There are three distinct types of poliovirus and two types of vaccines . The more popular one is the OPV, or oral polio vaccine. The second one, which needs to be injected, is IPV or inactivated poliovirus vaccine. Once this damage occurs, there is no cure to reverse it. The OPV contains a weakened form of the virus and helps build immunity in the intestine, where poliovirus multiplies, reducing the chances of it spreading from one child to another. On the other hand, the IPV contains an inactivated form of the virus and helps the body produce antibodies against all three types. These antibodies prevent the virus from reaching the nervous system and causing paralysis. Dr Nagarkar highlighted that there are also important safety considerations with the two types of polio vaccines. “OPV carries an extremely rare risk of vaccine-associated paralysis. In communities with poor immunisation coverage, the weakened vaccine virus can circulate over time and occasionally develop into a disease-causing strain. But despite the limited risk, OPV remains an important tool for controlling and containing polio outbreaks when required. The paediatrician added that apart from the vaccinations done as an infant, children should also receive additional OPV doses during Pulse Polio campaigns, regardless of their previous routine vaccinations. the virus continues to circulate internationally, so one should not let their guard down at any time While the last wild polio case was recorded in India over a decade ago. Note to readers: This article is for informational purposes only and not a substitute for professional medical advice. Always seek the advice of your doctor with any questions about a medical condition. Dr Rohini Nagarkar is a senior consultant in the paediatrics department at Surya Mother and Child Super Speciality Hospital, Pune.
In an interaction with HT Lifestyle on the occasion of World Polio Day, which was observed on October 24, paediatrician Dr Rohini Nagarkar explained how the two polio vaccinations differ, and why both are important in the effort to eradicate the disease. “Most infections cause little or no noticeable illness, but approximately one in 200 can lead to irreversible paralysis. The OPV used in India protects against poliovirus types 1 and 3, shared the paediatrician.
Therefore, maintaining high vaccination coverage is essential to preventing such outbreaks.
“Poliovirus enters through the mouth, multiplies in the intestine and spreads mainly through contaminated hands, food or water,” explained Dr Nagarkar. “However, IPV produces relatively limited intestinal immunity, which is why OPV remains important in preventing transmission,” stated Dr Nagarkar, noting that OPV and IPV together provide complementary protection. “IPV cannot cause polio because it contains no live virus,” she stated.
