Fractional Polio Vaccine Dosing Found Protective
Since the World Health Organization (WHO) recommended introducing at least a single dose of inactivated poliovirus vaccine (IPV) in routine immunization schedules in 2014, there have been global shortages.
Fractional-dose of IPV is one of the strategies suggested by the WHO to ensure vaccine availability.
A new study published by The Lancet on April 30, 2021, reviewed data comparing the effects of fractional with full-dose IPV vaccination to determine when seroconversion proportions with each strategy become similar in children aged 5 years and younger.
In this systematic review and meta-analysis from 16 databases, these researchers concluded 'There is no substantial difference in seroconversion between three doses of fractional-IPV and three doses of full-dose IPV, although the full dose gives higher titers of antibodies for poliovirus type 1, 2, and 3.
These researchers stated: Use of fractional IPV instead of the full dose can stretch supplies and possibly lower the cost of polio vaccination.
Since 2000, the IPV is most often given in the USA.
On April 28, 2021, the Global Polio Eradication Initiative reported nine countries confirmed polio cases in the last week, all involving vaccine-derived strains. Of countries reporting polio cases, (7) are in Africa, and (2) are located in the Middle East and Asia. Madagascar and Liberia reported their initial polio cases during 2021.