In a study conducted by Novavax, an American biotech company, their vaccine has shown 89% effectiveness on the U.K. variant of the virus, tested on 15,000 U.K. volunteers. This is in contrast to the vaccine’s effectiveness against the virus’ original strain, which is 96% effective. They later announced that 62 cases of COVID-19 occurred in the study; 56 occurred within the group that got the placebo, and 6 were seen in people who received the vaccine. 

The vaccine, similar to those produced by Pfizer and Moderna, are protein subunit vaccines. They are currently being rolled out in America, it has two doses which are taken separately 21 days apart. 

Smaller tests were also conducted in South Africa, where the vaccine showed an effectiveness of 49% to the South African variant of the virus, much lower than both the U.K. variant and original variant. Analysts suggest that the variant identified in South Africa seems to be mostly responsible for the COVID cases seen in the study. 

When vaccinated or due to a previous infection, the human immune system is able to make antibodies that recognize the coronavirus which in turn, destroys it. A virus mutates to bypass this, allowing it to change how it looks to antibodies, making them harder to lock on to. This results in a previous infection of the original virus being ineffective in protecting against the newer variants of the virus.