Two factors predominantly affect infection levels of Covid, with these being the level of immunity in the population and how much social mixing is ongoing.
When Omicron was first detected on British shores last November, an ideal combination of both elements – low roll-out of boosters and high levels of social mixing – allowed the variant to spread easily and eventually peak earlier this month.
Following the rapid roll-out of booster jabs – shown to reduce the risk of infection by nearly three quarters – and reductions in social activities, owing to Plan B restrictions, case numbers began to decline.
In fact, by the end of December, adults were averaging around 2.7 contacts a day – close to what was seen in the first lockdown.
