The UK has joined the US and other countries to offer a third, booster dose of a COVID-19 vaccine to all adults aged 18 or over.
The expansion of the booster programme comes amid growing fears over the level of protection against the new Omicron variant offered by only two shots of a vaccine.
In a Sunday evening televised announcement, Prime Minister Boris Johnson set a new target to give boosters to all adults who wanted one by the end of December in response to an expected ‘tidal wave of Omicron’ over the winter.
Health secretary Sajid Javid said the UK was “once again in a race between the virus and the vaccine” and that Omicron was spreading “at a phenomenal rate”, with cases doubling every two to three days.
He added that, in light of the urgency of the new target, primary care services would focus solely on the booster programme and ‘urgent’ needs. Non-urgent appointments face being delayed into the new year.
The UK has raised its COVID-19 alert level to level four – or a high or rising level of transmission – for the first time since May this year.
A report by the UK’s Health Safety Agency (HSA) late last week suggested that Omicron was ‘transmitting more effectively than Delta’, with the HSA estimating that, should the variant continues to grow at its present rate, it will become the dominant strain in the UK by mid-December.
At that rate, the HSA said the UK would exceed a million infections a day by the end of this month.
While these are early data, a study from the University of Oxford has reported that current vaccines induced lower levels of neutralising antibodies against Omicron.
The study, which blood samples collected from people who had received two doses of standard COVID-19 vaccination, concluded that the ‘substantial fall’ in neutralising antibodies meant ‘increased infections in previously infected, or vaccinated individuals may be likely’.
Professor Gavin Screaton, head of the University’s medical sciences division said: “Whilst there is no evidence for increased risk of severe disease, or death, from the virus amongst vaccinated populations, we must remain cautious, as greater case numbers will still place a considerable burden on healthcare systems.”
Professor of paediatrics and vaccinology, Matthew Snape, said the data were important but “only one part of the picture”. He added: “They only look at neutralising antibodies after the second dose, but do not tell us about cellular immunity, and this will also be tested using stored samples once the assays are available. Importantly, we have not yet assessed the impact of a ‘third dose’ booster, which we know significantly increases antibody concentrations, and it is likely that this will lead to improved potency against the Omicron variant.”