Analysis: top-up vaccines make key changes to our antibody defences, reducing the threat from Omicron
Covid-19, we should know by now, is a moving target. Back in autumn, the rollout of boosters to older age groups was contentious. Now they’re the single biggest focus. So why do boosters help so significantly compared with first and second jabs, and are we now on a conveyor belt towards needing an ever-increasing number of vaccine top-ups?
Even before Omicron, it was clear that boosters would be required to maintain the levels of protection against infection – although protection against severe illness appeared to be holding up well.
