Apologies, I misunderstood the context in which it was shared. And yes you are correct typically, but the current immunity levels in the USA are vastly different from that of the UK. Particularly in higher rate of infection over the last winter and widely available vaccines that are significantly more efficacious than the AZ vaccine. Additionally, the delaying of the second shot isn’t helping matters much in the UK. So while I agree, there is nothing to suggest this will happen in the United States despite previous events predicting otherwise.