TABLE 1.

Main features of Omicron

Mutations	Omicron has more than 50 mutations, 26‐32 of which are on spike protein; critical mutations are, S371L, G339D, S375F, S477N, S373P, T478K, N501Y, K417N, Q496S, Q493R, Q498R, Y505H, H655Y, N679K, D614G, and P681H. ²
Symptoms	Runny nose, fatigue (mild–severe), headache, sore throat, and sneezing. Omicron is more likely to infect upper respiratory tract than lungs, thus making it more infectious and less deadly than previous variants. ⁴ , ⁵
Vaccines efficacy	Populations having no immunization status are at higher risk of infections from Omicron with more severe attack. ² According to UK Health Security Agency (UKSHA), third COVID‐19 vaccine dose (booster) can provide higher protection against Omicron and reduces the risk of hospitalization up to 88% in infected patients. ⁶
Reinfection rate	In comparison to other VOCs, Omicron poses a higher risk of reinfection. ¹ A person who was previously infected with COVID‐19, has 5^1/2% more risk of reinfection with Omicron than reinfection with Delta variant. ⁷