How many doses of Inactivated Poliovirus Vaccine (IPV) does a child need by age 14?

Inactivated Poliovirus Vaccine (IPV) Requirements for Children by Age 14

Children should receive a total of 4 doses of IPV by age 14, administered at ages 2 months, 4 months, 6-18 months, and 4-6 years. 1, 2

Standard IPV Vaccination Schedule

• The Advisory Committee on Immunization Practices (ACIP) recommends that all children receive four doses of IPV at ages 2 months, 4 months, 6-18 months, and 4-6 years 1
• The first and second doses of IPV are necessary to induce a primary immune response, while the third and fourth doses ensure "boosting" of antibody titers to high levels 1
• The final dose should be administered at age ≥4 years regardless of the number of previous doses 2
• The fourth dose is not needed if the third dose is administered on or after the fourth birthday 1

Minimum Intervals Between Doses

• The minimum interval between doses is 4 weeks, although the preferred interval between the second and third doses is 2 months 1
• No additional doses are needed if more time than recommended elapses between doses (e.g., more than 4-8 weeks between the first two doses or more than 2-14 months between the second and third doses) 1

Immunogenicity and Protection

• 90-100% of children develop protective antibodies to all three types of poliovirus after administration of two doses of IPV, and 99-100% develop protective antibodies after three doses 1
• Studies from Sweden have shown that >90% of vaccinated persons maintained serum antibodies to poliovirus 25 years after receiving four doses of IPV 1
• The duration of immunity after receipt of the IPV series is long-term, possibly lifelong 1

Special Considerations

• If accelerated protection is needed (such as for travel to high-risk areas), the minimum interval between doses is 4 weeks 1, 2
• Children who have initiated the poliovirus vaccination series with one or more doses of OPV should receive IPV to complete the series 1
• Four doses of OPV or IPV in any combination by age 4-6 years is considered a complete series, regardless of age at the time of the third dose 1

Administration with Other Vaccines

• IPV can be administered simultaneously with other routinely recommended childhood vaccines including DTaP, Hib, HepB, varicella, and MMR 1
• Combination vaccines containing IPV are available and can reduce the number of injections needed 1

Common Pitfalls to Avoid

• Failing to administer the final dose at age ≥4 years, which is crucial for long-term immunity 2
• Unnecessarily restarting the vaccination series if intervals between doses are longer than recommended 1, 2
• Omitting the fourth dose when the third dose was given before the fourth birthday 1

The evidence strongly supports that a complete IPV series consisting of 4 doses provides robust and long-lasting protection against poliomyelitis, contributing significantly to the elimination of wild poliovirus in the Western Hemisphere 1.