The title is misleading. It is possible that Omicron is just as severe and that the effect in the study is because a large percentage of the population had some immunity from a previous infection or vaccine.
> South Africa has a quite high seroprevalence of prior infection, particularly after delta, and in some parts of South Africa up to 80 percent of people were exposed to previous infection. We don’t think it’s a question of virulence, but more a question of exposure to vaccination and prior infection, so we would be cautious to try and interpret that this is a less virulent strain. We’ll have to see what happens in other parts of the world before we make a call on this.
> South Africa has a quite high seroprevalence of prior infection, particularly after delta, and in some parts of South Africa up to 80 percent of people were exposed to previous infection. We don’t think it’s a question of virulence, but more a question of exposure to vaccination and prior infection, so we would be cautious to try and interpret that this is a less virulent strain. We’ll have to see what happens in other parts of the world before we make a call on this.