Brazil drug authority unveils composition of 2024 flu jabs
Brazil’s drug authority Anvisa has approved the composition of influenza vaccines to be used in the country in 2024. In a statement, the agency noted that changing the strains of the virus used in the jab is crucial to the effectiveness of the dose, as the virus adapts and mutates.
“The World Health Organization regularly examines all the subtypes of the influenza virus that circulate most frequently, in order to improve the effectiveness of inoculation,” the statement reads.
The strains
For 2024, trivalent vaccines produced from chicken eggs should have the following strains:
- Influenza A/Victoria/4897/2022 (H1N1)pdm09;
- Influenza A/Thailand/8/2022 (H3N2);
- Influenza B/Austria/1359417/2021 (B/Victoria strain).
For non-egg-based vaccines, the A (H1N1) virus strain must be a virus similar to influenza A/Wisconsin/67/2022 (H1N1)pdm09. The A (H3N2) strain must be a virus similar to influenza A/Massachusetts/18/2022 (H3N2), along with the B strain.
Quadrivalent vaccines, in turn, must contain a virus similar to the Influenza B/Phuket/3073/2013 virus (B/Yamagata lineage), in addition to the three mandatory strain types.
