The Omicron variant could still pose a threat to people who caught the virus at Christmas as immunity fades, GPs and experts are warning.
Despite catching Omicron in December, immunity against Covid for those who caught the mutant form of the virus over the festive period, either from a booster vaccine or immunity after an infection, could have wained.
And now there's a new dominant variant, BA.2 - a sister of the strain that was widespread at Christmas, Omicron BA.1 - Brits are being warned they could get sick with the virus again.
The good news is that both have been shown to be mild compared to other variants, as Britain's population takes up the vaccine.
The BA.2 variant, thought to have peaked in March, is continuing to be the fastest spreading variant to date and has driven a second Omicron wave.
Vulnerable groups, including the elderly, are being urged to come forward for their spring booster jabs to help top up their immunity against the virus.
Over the last two weeks, more than one million people so far have received their spring booster jabs, with the NHS expected to send out over 570,000 invites this week.
Health bosses have urged the public to come forward to get their jabs to help fight the waining immunity.
Dr Nikki Kanani, GP and deputy lead for the NHS Covid-19 vaccination programme, says it is vital that people get their jabs as “infections continue to rise”.
And Imperial College London Professor Paul Elliot, who led on the Covid surveillance study REACT-1, said the lifting of masks and mixing of households combined with waning immunity was behind the current infections across the country.
He warned Brits who caught the original Omicron variant at Christmas could still catch the new BA.2 variant.
However, data suggests that, while possible, catching both strains of Covid is rare, according to the UK Health and Security Agency (UKHSA).
In a March report, the UKHSA said that at least 43 double-Omicron infections had been sequenced out of 500,000 cases.
While researchers from Denmark’s Statens Serum Institut found 47 cases of BA.2 after BA.1 infection, out of 1.8 million cases.
They said: “Omicron BA.2 reinfections do occur shortly after BA.1 infections but are rare."
They added that these cases were "mostly found in younger unvaccinated individuals with mild disease".
The World Health Organisation said in February: “Reinfection with BA.2 following infection with BA.1 has been documented.
“However, initial data from population-level reinfection studies suggest that infection with BA.1 provides strong protection against reinfection with BA.2, at least for the limited period for which data are available.”
