Editor's note:For the latest flu coverage, visit https://www.aappublications.org/collection/influenza.
Eight more children have died of flu, as activity remains well above average for this time of year, according to new data from the Centers for Disease Control and Prevention (CDC).
The updated figures came as federal officials were choosing flu strains for next season’s vaccines and discussing the potential for a delay in availability.
The additional deaths bring the total of children who have died this season to 76. The CDC estimates as many as 41,500 people have died across all age groups.
Flu was widespread in 44 states, and about 4.4% of outpatient clinic visits were for flu during the week ending March 16. Over the past decade, outpatient visits for flu at this time of year ranged from 1.7% to 3.2%.
As many as 454,000 people have been hospitalized for flu, a rate of 47.1 per 100,000 people. Children ages 4 and under have the second highest rate, 59 per 100,000.
Influenza A (H3N2) has been predominant for the past few weeks after H1N1 viruses dominated earlier in the season. H3N2 also has been a subject of discussion among health officials choosing virus strains for next season’s vaccines. The World Health Organization (WHO) and Food and Drug Administration (FDA) delayed their decision on the H3N2 strain by about two weeks as experts collected more data to get the best match for circulating strains.
On Friday morning, the FDA’s Vaccines and Related Biological Products Advisory Committee approved an H3N2 strain. Its selections for all strains match the WHO’s. For the quadrivalent vaccines they recommend:
- an A/Brisbane/02/2018 (H1N1) pdm09-like virus;
- an A/Kansas/14/2017 (H3N2)-like virus;
- a B/Colorado/06/2017-like virus (B/Victoria/2/87 lineage); and
- a B/Phuket/3073/2013-like virus (B/Yamagata/16/88 lineage).
For trivalent vaccines, they recommend the influenza B virus component be a B/Colorado/06/2017-like virus of the B/Victoria/2/87 lineage.
Pharmaceutical industry representatives said the delay in strain selection could mean a delay in vaccine availability in the fall, but they will have a better idea in the coming weeks.
The CDC and the Academy recommend everyone 6 months and older get vaccinated against the flu. Flu vaccine is 61% effective against medically attended influenza for children and 47% for the overall population, according to interim data from the CDC.
This season, inactivated influenza vaccine has been the primary vaccine choice, while quadrivalent live attenuated influenza vaccine may be used for children who would not otherwise receive a vaccine, according to AAP policy.However, the AAP recently announced that it will not have a preference between the two vaccines next season.
