Safety and immunogenicity of a primary series of Sabin-IPV with and without aluminum hydroxide in infants

Abstract Background An inactivated poliovirus vaccine (IPV) based on attenuated poliovirus strains (Sabin-1, -2 and -3) was developed for technology transfer to manufacturers in low- and middle-income countries in the context of the global polio eradication initiative. Method Safety and immunogenicity of Sabin-IPV (sIPV) was evaluated in a double-blind, randomized, controlled, dose-escalation trial in the target population. Healthy infants ( n = 20/group) aged 56–63 days, received a primary series of three intramuscular injections with low-, middle- or high-dose sIPV with or without aluminum hydroxide or with the conventional IPV based on wild poliovirus strains (wIPV). Virus-neutralizing titers against both Sabin and wild poliovirus strains were determined before and 28 days after three vaccinations. Results The incidence of local and systemic reactions was comparable with the wIPV. Seroconversion rates after three vaccinations were 100% for type 2 and type 3 polioviruses (both Sabin and wild strains) and 95–100% for type 1 polioviruses. Median titers were high in all groups. Titers were well above the log2 (titer) correlated with protection (=3) for all groups. Median titers for Sabin-2 were 9.3 (range 6.8–11.5) in the low-dose sIPV group, 9.2 (range 6.8–10.2) in the low-dose adjuvanted sIPV group and 9.8 (range 5.5–15.0) in the wIPV group, Median titers against MEF-1 (wild poliovirus type 2) were 8.2 (range 4.8–10.8) in the low-dose sIPV group, 7.3 (range 4.5–10.2) in the low-dose adjuvanted Sabin-IPV group and 10.3 (range 8.5–17.0) in the wIPV group. For all poliovirus types the median titers increased with increasing dose levels. Conclusion sIPV and sIPV adjuvanted with aluminum hydroxide were immunogenic and safe at all dose levels, and comparable with the wIPV. EudraCTnr: 2011-003792-11, NCT01709071.