WHO finds bivalent oral polio vaccine more effective than trivalent vaccine

A World Health Organization study in India showed that bivalent oral poliovirus vaccines for types 1 and 3 poliovirus were more effective than a trivalent oral poliovirus vaccine for types 1, 2 and 3 in newborn babies.

This bivalent vaccine was non-inferior to the monovalent vaccines for types 1 and 3 poliovirus, the study, reported in the journal Lancet, revealed.

The controlled, randomized, double blind trial randomly assigned 900 newborn babies to one of five different vaccines groups - types 1 and 3 bivalent vaccines, types 1, 2 and 3 trivalent vaccines, a type 1 monovalent vaccine, a type 2 monovalent vaccine and a type 3 monovalent vaccine - reports.

After randomization, the infants were immediately given one vaccine dose. Serum samples were taken after 30 and 60 days to test for seroconversion. After the 30 day sample, another dose was given.

The cumulative seroconversion was 86 percent for the bivalent vaccines, 63 percent for the trivalent vaccine and 90 percent for the type 1 monovalent vaccines.

Seroconversion to the type 2 poliovirus was no different between the monovalent type 2 vaccine and the trivalent vaccine after either dose.

The cumulative seroconversion for type 3 poliovirus was 74 percent for the bivalent vaccine, 52 percent for the trivalent vaccine and 84 percent for the monovalent type 3 vaccine.

“The major advantages of the bivalent vaccine according to [the advisory committee on poliomyelitis eradication] is that it will enhance individual and population immunity simultaneously for both poliovirus types 1 and 3, without any serious loss in immunogenicity compared with the monovalent oral poliovirus vaccine,” the researchers wrote, according to “Bivalent oral poliovirus vaccine is already being used on a large scale to increase population immunity against and accelerate the eliminate of the final chains of transmission of these two remaining wild polioviruses, especially in areas where both poliovirus types 1 and 3 co-circulate.”