Titers of postdose three G1 serum-neutralizing antibody (PD3 G1 SNA) appear to be the best correlate of protection for pentavalent rotavirus vaccine (RV5), reported G. Frank Liu, PhD, and his associates at Merck in Kenilworth, N.J.

The researchers discovered this by analyzing data from five clinical trials of RV5 at both the individual and aggregated population level. Also, by looking at immunogenicity measures and case status of individuals from phase 2 and 3 trials of RV5, they found that “higher PD3 G1 SNA titers are associated with lower odds of contracting any [rotavirus gastroenteritis].”

In the phase 2 and 3 studies, better RV5 efficacy was linked to higher PD3 G1 SNA geometric mean titers (GMT) ratios and higher PD3 serum anti-RV IgA GMT ratios. In analyses of both individual- and population-level data, the PD3 G1 SNA titer correlated more closely with efficacy for RV5 than did serum anti-RV IgA, Dr. Liu and his associates concluded.

Read more at (Hum Vaccin Immunother. 2017. doi: 10.1080/21645515.2017.1356522 ).