Oral Polio Vaccine
Comparing Oral and Inactivated Polio Vaccines
There are two general polio vaccine types. One type is inactivated polio vaccine (IPV), meaning that the vaccine contains no live poliovirus. The other is live oral polio vaccine, which contains live but weakened poliovirus. Until recently, the oral vaccine was recommended for most children in the United States. It helped rid the United States of polio, and is still used in many parts of the world (largely because it is less expensive than the inactivated polio vaccine).
Both vaccines give immunity to polio, but the oral form is better at keeping the disease from spreading to other people. However, for a few people (about 1 in 2.4 million), oral polio vaccine actually causes polio (known as vaccine-associated paralytic polio).
Since the risk of getting polio in the United States is now extremely low, experts believe that using the oral vaccine is no longer worth the slight risk, except in limited circumstances, which your doctor can describe. The polio shot (inactivated polio vaccine) does not cause polio.
(Click Polio Vaccine to learn more about the inactivated vaccine.)
Vaccine-associated paralytic poliomyelitis is a rare adverse reaction following live oral polio vaccine. It is caused by vaccine-derived poliovirus. One case occurred for every 2 to 3 million doses of oral vaccine administered. This resulted in 8 to 10 cases of vaccine-associated paralytic poliomyelitis each year in the United States.
From 1980 through 1999, vaccine-associated paralytic poliomyelitis accounted for 95 percent of all cases of paralytic poliomyelitis reported in the United States.
(Click Vaccine-Associated Paralytic Poliomyelitis to learn more about this rare but serious reaction to the oral polio vaccine.)