Almost three-quarters of Americans are now estimated to have some level of immunity to the Omicron Covid variant that created havoc after it emerged late last year just as people hoped the pandemic was finally waning.
The subsequent Omicron wave that assaulted the US this winter has, however, bolstered its defenses, leaving enough protection against the coronavirus that future surges will probably require much less – if any – dramatic disruption to society, experts reckon.
