COVID-19 booster shots more likely as variants could cut efficacy of vaccines: GlobalData

If new SARS-CoV-2 variants continue to develop, they could affect not only the effectiveness of COVID-19 vaccines but also the natural immunity that COVID-19 survivors have developed – making annual booster shots required for COVID-19 immunity, says GlobalData.

Johanna Swanson, Product Manager at GlobalData, comments, “Of the several natural variants that have recently been identified, the B.1.1.7 variant is potentially more troubling, as there is evidence that it alters the effectiveness of some vaccines.”

Clinical trials for the Pfizer and Moderna vaccines indicate a reduction in sera neutralisation of the B.1.351 variant, and other studies have shown there could be a six to ten-fold lower binding affinity for antibodies to the variant. Additionally, Johnson & Johnson’s vaccine had 57 per cent efficacy in South Africa, where the variant is prevalent, versus 72 per cent in the US, and Novavax’s vaccine had 49 per cent efficacy in South Africa versus 90 per cent in the UK.

This is further supported by AstraZeneca’s vaccine trial in South Africa, which had an under 25 per cent efficiency against mild and moderate disease and did not achieve the minimal international standards for emergency use. While the vaccine was not effective at preventing mild and moderate disease, it could still prevent more severe outcomes.

The P.1 variant has some of the same mutations as the B.1.351 variant and could have a higher chance of re-infecting people. More research needs to be conducted on this variant to monitor its effects.

Swanson continues, “As there is already some indication of COVID-19 re-infections and possible waning immunity from naturally recovered COVID-19 patients, yearly boosters may be required for COVID-19. However, it is important to note that, despite the presence of these variants in the population, the vaccines are still likely to prevent severe outcomes such as hospitalisation and death.”

Pfizer and Moderna are already working on developing booster shots for their vaccines to improve their effectiveness against the B.1.351 strain. This would benefit those who have a weak level of response to COVID-19 infection as they may have a shorter duration of immunity and weaker protection from re-infection. Naturally recovered COVID-19 patients should also consider getting vaccinated.

Swanson adds, “Vaccines can offer a more consistent level of protection and a more robust immune response of neutralising antibodies. Single-dose boosters provided to patients who have naturally recovered from COVID-19 could increase and extend the duration of their immune response.”