Oral and injected polio vaccines work together to protect children

Two different polio vaccines work together to protect children from the disease. Paediatrician Dr Rohini Nagarkar shared details about the oral polio vaccine and the injectable polio vaccine.

Vaccine Types

There are three types of poliovirus and two types of vaccines. The oral polio vaccine, or OPV, uses a weakened form of the virus. It builds immunity in the intestine where the virus multiplies, which stops it from spreading to other children. In India, OPV protects against poliovirus types 1 and 3. The second option is the inactivated poliovirus vaccine, or IPV, which is given through an injection. IPV uses an inactivated form of the virus and helps the body make antibodies against all three types of poliovirus. These antibodies stop the virus from reaching the nervous system and causing paralysis. Dr Nagarkar noted that IPV does not build strong intestinal immunity, which makes OPV necessary for stopping transmission. Both vaccines together offer full protection.

Safety and Risks

Dr Nagarkar explained that IPV cannot cause polio because it has no live virus. OPV carries a very rare risk of vaccine-associated paralysis. In places with low immunisation rates, the weakened virus from the vaccine can spread and turn into a disease-causing strain. Keeping vaccination coverage high stops these outbreaks. Even with this small risk, OPV stays a key tool to control polio outbreaks. Children must also get extra OPV doses during Pulse Polio campaigns along with their routine infant vaccines. India recorded its last wild polio case more than ten years ago, but the virus still circulates globally.

Context

Polio is a viral disease that mainly affects children and spreads through contaminated food, water, or hands. While most infections cause mild illness, about one in two hundred cases leads to permanent paralysis with no cure. Global health campaigns continue to use both oral drops and injections to keep populations safe until the virus is completely gone.