The purpose of this Phase 2 study is to determine whether a lower dose of inactivated polio vaccine (IPV) injected into the skin (intradermal administration) can work equally well or better than the standard dose injected into the muscle (intramuscular administration).
There are more immune cells in the skin than in the muscle, and other vaccines have been shown to require a lower dose when administered intradermally. The study is being done in 231 participants infected with HIV because HIV-infected people are known to respond less well to vaccines than other groups, so it is particularly important to know if IPV might work better in HIV-infected people if administered intradermally.
If it is possible to lower the dose of IPV by intradermal administration, this would make inactivated polio vaccine more affordable in the developing countries where it is most needed.
The Journal of Infectious Diseases published results on June 15, 2015.
Results: Baseline immunity was 87%, 90%, and 66% against poliovirus serotypes 1, 2, and 3, respectively. After vaccination, antibody titers increased a median of 64-fold. Vaccine response to 40% of the standard dose administered intradermally was comparable to that of the standard dose of IPV administered intramuscularly and resulted in higher (although not significantly) antibody titers. Intradermal administration had higher a incidence of local side effects (redness and itching) but a similar incidence of systemic side effects and was preferred by study participants over intramuscular administration.
Conclusions: A 60% reduction in the standard IPV dose without reduction in antibody titers is possible through intradermal administration.