From the Guidelines
The recommended schedule for Inactivated Poliovirus Vaccine (IPV) administration consists of four doses given at specific intervals during childhood, with doses administered at 2,4, and 6 through 18 months and 4 through 6 years of age, as stated in the Pediatrics study 1. The minimum interval between doses 1 and 2 and between doses 2 and 3 is 4 weeks, and the minimum interval between doses 3 and 4 is 6 months, according to the Pediatrics study 1. Some key points to consider when administering the IPV schedule include:
- The minimum age for dose 1 is 6 weeks, as indicated in the Pediatrics study 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, as noted in the Pediatrics study 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, as stated in the Pediatrics study 1. The Centers for Disease Control and Prevention (CDC) and other health organizations recommend following this schedule to ensure optimal immunity against poliomyelitis, a potentially devastating disease that can cause permanent paralysis, as supported by the MMWR Recommendations and Reports study 1. Key considerations for the administration of IPV include:
- The vaccine is administered as an intramuscular injection, typically in the anterolateral thigh for infants and in the deltoid muscle for older children and adults.
- The vaccine works by introducing inactivated (killed) poliovirus strains that cannot cause disease but stimulate the immune system to produce protective antibodies against all three poliovirus types.
- Adults who were not fully vaccinated as children and are at increased risk of exposure should complete the series, as recommended by the MMWR Recommendations and Reports study 1.
From the Research
Inactivated Poliovirus Vaccine (IPV) Administration Schedule
The recommended schedule for Inactivated Poliovirus Vaccine (IPV) administration is as follows:
- A two-dose schedule of IPV beginning at ≥14 weeks of age to achieve at least 90% immune response, as recommended by the Strategic Advisory Group of Experts on Immunization (SAGE) 2
- The schedule of two full IPV doses could begin as early as 6 weeks of age, with cumulative immune responses of 98-99% observed in participants who received IPV at 6 weeks and 9 months 2
- A sequential vaccination schedule of two doses of IPV followed by two doses of OPV for routine childhood vaccination, as recommended by the Advisory Committee on Immunization Practices (ACIP) 3
Immunogenicity of IPV Schedules
The immunogenicity of different IPV schedules is as follows:
- One full dose of intramuscular IPV seroconverted 33%, 41%, and 47% of infants against serotypes 1,2, and 3 on average, whereas 2 full doses seroconverted 79%, 80%, and 90%, respectively 4
- Two full or fractional doses of IPV given after 10 weeks of age is likely to protect >80% of recipients against poliomyelitis if poliovirus reemerges after withdrawal of OPV serotypes 4
- After two doses of IPV, 96 to 100% of infants had antibodies to poliomyelitis viruses types 1,2, and 3, and after a third dose of vaccine (IPV or OPV), all but one child had antibodies to all three poliovirus types 5
Fractional Dose IPV
The use of fractional dose IPV is being studied as a strategy to improve access to the vaccine, with a systematic review and meta-analysis aiming to compare the effects of fractional with standard doses of IPV 6