Vaccination and Prior COVID-19 infection Confer Enhanced Immunity Against Omicron

  A study published in the New England Journal of Medicine has shown that a combination of full mRNA vaccination, a booster dose and natural immunity against COVID-19 due to the previous infection significantly reduced the risk of severe infection from Omicron variants. Study details:   Results:    The effectiveness of the previous infection, BNT162b2 vaccination, and hybrid immunity against symptomatic omicron infection with BA.1 were comparable to that with BA.2 (Table 1), with previous infection and three doses of either of the mRNA vaccines showing the highest effectiveness. The effectiveness of the previous infection, vaccination, and hybrid immunity against severe, critical, or fatal Covid-19 due to BA.1 and BA.2 was more than 90 and 70%, respectively.

The severity of infections was low, with only 0.3% of infections progressing to severe, critical, or fatal Covid-19. The…