From the Guidelines
All children should receive four doses of IPV (Inactivated Polio Vaccine) at ages 2,4, and 6-18 months and 4-6 years to prevent poliomyelitis, as recommended by the Advisory Committee on Immunization Practices (ACIP) 1. The standard schedule for poliovirus immunization remains 4 doses of inactivated poliovirus vaccine at 2,4, and 6 through 18 months and 4 through 6 years of age, with a minimum interval of 4 weeks between doses 1 and 2, and between doses 2 and 3, and a minimum interval of 6 months between doses 3 and 4 1. Some key points to consider when administering the IPV vaccine include:
- The minimum age for dose 1 is 6 weeks 1
- Minimal age and intervals should be used when there is imminent threat of exposure, such as travel to an area in which polio is endemic or epidemic 1
- The final dose in the inactivated poliovirus vaccine series should be administered at 4 through 6 years of age, regardless of the previous number of doses administered before the fourth birthday, and at least 6 months since the last dose was received 1 IPV is administered as an injection, typically in the leg or arm depending on age, and contains killed poliovirus that cannot cause disease but stimulates the immune system to produce antibodies against all three poliovirus types 1. Unlike the oral polio vaccine (OPV), IPV cannot cause vaccine-derived polio because it contains inactivated virus, making it a safer option for routine childhood polio vaccination in the United States 1. Side effects are generally mild and may include soreness at the injection site, low-grade fever, or irritability, and IPV is particularly important for travelers to regions where polio remains endemic or has recently circulated, and for healthcare workers who might be exposed to people with polio 1.
From the Research
IPV Vaccine Overview
- The IPV vaccine is used to prevent poliomyelitis, and its immunogenicity and safety have been evaluated in several studies 2, 3, 4, 5, 6.
- The vaccine can be administered through intramuscular or intradermal routes, with the latter showing potential for dose-sparing 2, 6.
Immunogenicity and Safety
- Studies have shown that the IPV vaccine is highly immunogenic, with seropositivity rates reaching 100% for all three poliovirus serotypes after booster immunization 4, 5.
- The vaccine has also been found to be safe, with adverse events being mild or moderate and occurring at a low frequency 4, 5.
- The geometric mean titers of neutralizing antibodies for types 1-3 have been found to increase significantly after booster immunization, indicating a robust immune response 5.
Administration Routes and Dosing
- Intradermal administration of fractional doses of IPV has been found to be a effective dose-sparing strategy, inducing antibodies at titers comparable to those after immunization with full human dose delivered intramuscularly 2, 6.
- The use of IPV for the first 2 doses of the polio vaccine series, followed by either IPV or OPV for the third and fourth doses, has been recommended to reduce the risk of vaccine-associated paralytic poliomyelitis (VAPP) 3.
Booster Dose and Immune Persistence
- A booster dose of IPV has been found to have good immunogenicity and safety profile, providing effective protection against poliovirus 4, 5.
- Immune persistence following primary immunization has been found to be high, with seropositivity rates remaining above 99% for all three poliovirus serotypes 14 months after primary immunization 5.