1. World Health Organization. https://www.who.int/activities/tracking-SARS-CoV-2-variants (accessed August 2022).
2. Higdon, M. M. et al. Lancet Infect. Dis. 22, 1114–1116 (2022).
3. World Health Organization. https://www.who.int/groups/technical-advisory-group-on-covid-19-vaccine-composition-(tag-co-vac) (accessed August 2022).
4. World Health Organization. https://www.who.int/publications/m/item/who-target-product-profiles-for-covid-19-vaccines (accessed August 2022).
5. Subissi, L. et al. Nat. Med. 28, 1110–1115 (2022).