The effectiveness of COVID-19 vaccinations is being affected by the emergence of variants of SARS-CoV-2. This can become more problematic as the virus continues to spread, increasing your chance of mutating. These variants can affect not only the effectiveness of vaccines, but also the natural immunity that survivors of COVID-19 have developed, making annual booster vaccines necessary for COVID-19 immunity.
Several natural variants have been identified, including variant B.1.1.7 first identified in the United Kingdom, variant B.1.351 first identified in South Africa and variant P.1 first identified in Brazil. Variant B.1.1.7 is currently considered to be about 50% more transmissible than the original SARS-CoV-2 strain, and possibly more deadly. However, there is no indication that B.1.1.7 will reduce the effectiveness of Moderna or Pfizer COVID-19 vaccines. This is supported by the fact that variant B.1.1.7 is neutralized by the sera from the Pfizer and Moderna vaccine recipients. Still, there is some laboratory evidence of reduced neutralization of variant B.1.1.7 by convalescent plasma from patients with COVID-19. Novavax reported that his vaccine was 85% effective with the variant versus 89% with the non-variant strain, and AstraZeneca / Oxford reported that his vaccine was 74% effective with the variant versus 84% with the non-variant strain.
Variant B.1.351 is potentially more problematic. Clinical trials for the Pfizer and Moderna vaccines indicate a reduction in serum neutralization of variant B.1.351, and other studies have shown that there could be six to 10 times less binding affinity for variant antibodies. In addition, the Johnson & Johnson vaccine was 57% effective in South Africa, where the variant is prevalent, against 72% in the USA, and the Novavax vaccine was 49% effective in South Africa against 90% in the United Kingdom. United. However, the director of the World Health Organization, Kate O’Brien, indicated that these results may have some uncertainty, as they were based on a low number of cases in South Africa. Variant B.1.351 may have a greater chance of reinfect people who have been infected by previous strains of the SARS-CoV-2 virus.
Variant P.1 has some of the same mutations as variant B.1.351 and may have a greater chance of infecting people again. More research needs to be done on this variant to monitor its effects.
Pfizer and Moderna are already working on the development of booster vaccines to improve their effectiveness against the B.1.351 strain. As there is already some indication of COVID-19 reinfections and possible decrease in the immunity of patients with naturally recovered COVID-19, annual reinforcements may be necessary for COVID-19. However, it is important to note that, despite the presence of these variants in the population, vaccines can still prevent serious outcomes, such as hospitalization and death.
As such, naturally recovered COVID-19 patients should also consider vaccination. Those who have a low level of response to COVID-19 infection may have a shorter duration of immunity and weaker protection against reinfection. Vaccines can offer a more consistent level of protection and a more robust immune response to neutralizing antibodies. Single-dose boosters provided to patients who have recovered naturally from COVID-19 can increase and extend the duration of their immune response.