Aluminum hydroxide–adjuvanted vaccines with reduced doses of inactivated polio vaccine (IPV-Al) were noninferior to standard inactivated poliovirus vaccine (IPV) in a large trial in the Dominican Republic, said Luis Rivera, MD, of the Hospital Maternidad Nuestra Señora de la Altagracia, Santo Domingo, Dominican Republic, and his associates.
If these findings are replicated in phase III trials and regulatory approval follows, such vaccines could be low-cost replacements for standard IPV and oral poliovirus vaccines in low-resource countries, the study authors suggested.
In this phase II, blinded, randomized trial with three investigational IPV-Al groups and one IPV group, the vaccines were given at 6 weeks, 10 weeks, 14 weeks, and 18 weeks to 823 infants who had not previously received any polio vaccination. The three new IPV-Al vaccines all proved to be noninferior to IPV for poliovirus types 1, 2, and 3.
For 1/10 IPV-Al, the seroconversion rates for the different poliovirus types were 98.5% (type 1), 94.6% (type 2), and 99.5% (type 3), compared with 100% (type 1), 98.5% (type 2), and 100% (type 3) for IPV.
This and the results from other studies “have paved the way for further clinical investigations of IPV-Al in phase III trials,” Dr. Rivera and his associates wrote.
“The low frequency of adverse events in this phase II trial suggests that a safety evaluation is not necessarily justified,” they concluded.
The Bill & Melinda Gates Foundation funded the study. The authors had no disclosures.
Read more in the Lancet Infectious Diseases (