The World Health Organization finalized its recommendations for the composition of the 2019-20 flu vaccine March 21.
Three things to know:
1. The WHO shared initial recommendations on what 2019 H1N1 and influenza B components should be included in the vaccine Feb. 21. However, the group postponed its decision on the vaccine's H3N2 composition to conduct further research.
2. The WHO recommended vaccine-makers use an A/Kansas/14/2017-like virus in the 2019-20 flu shot, which marks a change from the H3N2 component used in the 2018-19 flu vaccine.
3. The postponed recommendation, paired with major changes to vaccine composition, could cause delays in the vaccine manufacturing process, reports CIDRAP News. The WHO said it is working with manufacturers to limit this risk, but noted counties should prepare for a potential two- to four-week delay in vaccine supplies.