Trivalent and quadrivalent inactivated influenza vaccine (IIV) and quadrivalent live attenuated influenza vaccine (LAIV) all gave statistically significant protection against any flu in U.S. children aged 2-17 years in 2015-2016, Katherine A. Poehling, MD, of Wake Forest University, Winston-Salem, N.C., and her associates reported in a study of more than 1,000 children.
“This study also adds to the clinical evidence suggesting that ,” the researchers concluded.
Cynthia Goldsmith/CDC photo #10073
This negative-stained transmission electron micrograph (TEM) depicts the ultrastructural details of an influenza virus particle, or “virion.”
“The 2015-2016 season northern hemisphere trivalent IIV included A/California/7/2009 (H1N1)-like virus, a new A/Switzerland/9715293/2013 (H3N2)-like virus, and a new B/Phuket/3073/2013-like virus (Yamagata lineage),” the investigators noted. “Quadrivalent IIV was similar to trivalent IIV and also included B/Brisbane/60/2008-like virus (Victoria lineage). LAIV was similar to quadrivalent IIV, except that it contained A/Bolivia/559/2013.”
Of the 1,012 children enrolled, 59% were unvaccinated, 10% were given LAIV, 10% received trivalent IIV, 20% were given quadrivalent IIV, and 1% received IIV of “unknown valence.”
Vaccine efficacy against any influenza was 46% for LAIV and 65% for IIV, compared with no vaccination. But only IIV gave “significant protection against influenza A(H1N1)pdm09 strains in the total study population,” Dr. Poehling and her associates said. Vaccine efficacy against influenza A(H1N1)pdm09 strains was 50% for LAIV and 71% for IIV.
Read more in Clinical Infectious Diseases (2017 Oct 4. doi: 10.1093/cid/cix869).