How does the Polio Vaccine Work
Polio is a major disease that affects the infants. India in association with various international health organizations such as the World Health Organization (WHO) has been able to create awareness and fight against the disease. India is at this point of time declared Polio free, however, the fight continues with regular vaccinations and child health checkups.
- Oral Polio Vaccine (OPV): OPV comes in the form of liquid drops and consists of weak polioviruses. These attenuated (weak) viruses are taken up by our gut cells. As these are weak viruses they do not cause infection but stimulate the production of protective particles called as “ antibodies”. These protect vaccinated children from the wild poliovirus infection. Moreover, the virus is present in the stool of vaccinated child and can spread to other contacts thereby providing immunity to people living in the vicinity (Herd immunity).
- Inactivated Polio Virus vaccine: It is a “killed vaccine” i.e. the virus is dead. It is given in the form of an injection. Protective antibodies are made by the blood in response to circulating dead polio virus. If the same child gets an infection in future then these antibodies protect from the damaging effects of the virus on the nervous system.
Adherence is Must
To achieve high levels of these protective antibodies it is important to get these vaccines as suggested in the immunization schedule. The first dose is given soon after birth. Subsequent doses are given at 6 weeks, 10 weeks and 14 weeks. Further booster doses are required to maintain high antibody levels.
India has been declared Polio Free by World Health Organisation on 27th March 2014. The last reported cases of Polio were from Gujarat and West Bengal in January 2011. In order to maintain polio-free status, it is important that all children below 5 years should be immunized. Pulse Polio Initiative aims to achieve this goal and therefore on Pulse Polio days all children below 5 years are given oral polio drops.
