What is polio vaccine given for?
Polio vaccine is given to protect against poliomyelitis, the dreaded childhood disease leading to paralysis of various groups of muscles. Polio is caused by 3 types of poliovirus- type I, II & III.

What are the types of polio vaccine?
There are two types of polio vaccine, one is live oral polio vaccine (OPV) & the other is injectable killed polio vaccine (IPV). Both these vaccines contain all the 3 types of polioviruses.

Which of the 2 types of polio vaccine is used?
India & many other countries use only OPV. Infact IPV is not available in India. IPV was the first polio vaccine to be marketed in the world. Western countries like USA used IPV for mass vaccination and were immediately rewarded with significant drop in polio cases. Subsequently OPV was introduced in the market. Because of convenient oral route and cost effectiveness, the whole world started using predominantly OPV. Extensive coverage with OPV in the Western Hemisphere almost eradicated poliomyelitis. Now that there are no cases of clinical polio for 10 years or more, USA has totally switched over to only IPV and does not use OPV anymore.

After polio is eradicated from a country, it may be prudent to switch over to IPV.

How are polio vaccines available?
OPV is available as vial containing multidoses. The dose is 2 drops per dose. IPV is available as a single dose vial containing 0.5 ml of vaccine. It is also available as combination vaccines containing IPV+DPT or IPV+DPT +Hepatitis B or IPV+DPT+Hib or IPV+DPT+Hepatitis B+Hib.

When is OPV given?
OPV is given as 2 drops per orally. The first dose is given at birth –15 days as zero dose OPV. Next 3 primary doses are given at 4 weeks interval starting at 6—8 weeks of age. It is given along with 3 primary doses of DPT. Indian Academy of Pediatrics recommends a 5th primary dose at 6 months.

When is the booster dose of OPV given?
A booster dose of OPV is recommended at 15—18 months of age and a 2nd booster at 4—6 years of age.

What are the side effects of polio vaccines?
OPV has minimum side effects. It can lead to GI upset like diarrhea, vomiting. It does not lead to fever. Most of the side effects seen with OPV +DPT are due to the DPT vaccine. The most important but extremely rare side effect with OPV is vaccine-associated paralysis (VAP). It occurs in 1 in million doses. Massive benefits of OPV far outweigh the rare risk of paralysis. In west, though, it can become a medico –legal problem. Hence in west, people use first IPV to induce systemic antibodies & then use OPV, which will lead to local gut immunity without the risk of vaccine induced paralysis due to the partial immunity conferred by prior IPV.

IPV can lead to local side effects like pain, swelling, redness and tiredness in 10 –20 % of vaccinees. It can lead to fever, which is mild & lasts for 24—48 hours.

 

Page 1 of 2 Next
View Page 1 2