What is the current recommended polio vaccination regimen (how many doses, when, and what route) due to vaccine shortages?

What is the current recommended polio vaccination regimen (how many doses, when, and what route) due to vaccine shortages?

• A. Fractional dose (0.1 ml) intradermally at 6 and 14 weeks.
• B. Single full dose (0.5 ml) intramuscularly.
• C. Two full doses intradermally at 6 and 14 weeks.
• D. Oral polio vaccine only.

Answer: (A)

The main idea is that during polio vaccine shortages, programs use fractional-dose IPV given intradermally to stretch the supply while maintaining protection. Each intradermal dose is 0.1 mL, and giving two such doses at 6 and 14 weeks has been shown to elicit neutralizing antibodies against all three poliovirus serotypes comparable to a single full 0.5 mL intramuscular dose. The intradermal route is effective because the skin’s abundant antigen-presenting cells amplify the immune response with much less antigen, so two small doses can achieve similar immunity as one larger dose. This schedule also fits early infancy vaccination timelines and helps ensure continued protection when vaccine supply is limited. Other options either use more antigen per dose than needed or rely on routes or regimens that aren’t aligned with current shortage guidance, and relying solely on oral polio vaccine ignores the broader shift toward IPV with concerns about vaccine-derived poliovirus.

The main idea is that during polio vaccine shortages, programs use fractional-dose IPV given intradermally to stretch the supply while maintaining protection. Each intradermal dose is 0.1 mL, and giving two such doses at 6 and 14 weeks has been shown to elicit neutralizing antibodies against all three poliovirus serotypes comparable to a single full 0.5 mL intramuscular dose. The intradermal route is effective because the skin’s abundant antigen-presenting cells amplify the immune response with much less antigen, so two small doses can achieve similar immunity as one larger dose. This schedule also fits early infancy vaccination timelines and helps ensure continued protection when vaccine supply is limited. Other options either use more antigen per dose than needed or rely on routes or regimens that aren’t aligned with current shortage guidance, and relying solely on oral polio vaccine ignores the broader shift toward IPV with concerns about vaccine-derived poliovirus.