By Clare Wilson.
A road sign in the UK.
There is a photo of Maureen McLean.
The emergence of the omicron variant has caused concern worldwide, but there is cause for some optimism, as new evidence shows that a third dose of vaccine can take people's coronaviruses protection to unexpectedly high levels.
The covid-19 vaccines from Oxford/AstraZeneca and Pfizer/BioNTech may eventually need a third shot. The UK began offering third doses of vaccine to people who are 50 or older in September after studies suggested vaccine effectiveness was waning. It later expanded to include those over 40.
The initial signs for how well third jabs are working have been positive despite the fact that there was disappointment that boosters were needed after only six months. A randomised trial found that people who had received a third dose of the Pfizer/BioNTech vaccine had less infections than people who only had two jabs.
