Table 1 Characteristics of key covid-19 variants
Variant | First identified | Characteristics |
|---|---|---|
Alpha | December 2020, UK | More transmissible than the original strain. Spike protein mutations affecting vaccine effectiveness (Duong 2021; Adesola and Idris 2022) |
Beta | December 2020, South Africa | Â |
Delta | December 2020, India | More transmissible than the Alpha variant. May cause more severe illness. Spike protein mutations affecting vaccine effectiveness (Zhan et al. 2022) |
Gamma (P.1) | Tokyo, Japan | Increased transmissibility. Potential to evade immunity. Associated with a higher rate of reinfection. Comprises two sub-variants (28-AM-1 and 28-AM-2) carrying K417T, E484K, and N501Y mutations. Caused widespread infection in Manaus, Brazil in early 2021 despite high prior immunity. May present with different symptoms compared to non-variant of concern infections (Luna-Muschi et al. 2022) |
Omicron | November 2021, South Africa | A large number of spike protein mutations affect vaccine effectiveness. Highly transmissible (He et al. 2021) |
JN.1 | September 2023, United States | Highly mutated sub-variant of Omicron. Additional L455S mutation in spike protein for extra immune evasion. Highly transmissible. Dominant strain in the US, accounting for over 90% of cases. Rapid evolution and prevalence increase. More resistant to antibodies but less contagious. Symptoms include runny nose, fatigue, fever, headaches, cough, sore throat, shortness of breath, digestive issues, and loss of taste and smell (Kaku et al. 2024) |