PEOPLE affected by Omicron at Christmas have been warned they are still at risk from the bug.
Although Christmas only feels like yesterday, enough time has passed for immunity to the bug to wear off – either through infection or a boost.
And now that a new Covid variant is dominant (BA.2), it is possible that people will get sick again.
The BA.2 strain is a sister to Omicron BA.1 that dominates over the festive season, meaning they come from the same family or “line”.
The good news is that both BA.1 and BA.2 have proven to be mild compared to previous strains, especially given that the population is largely vaccinated.
And the elderly and most vulnerable are getting their immunity to the virus replenished with spring boosters.
Over a million people have received a Spring Booster in the last two weeks and 570,000 more invitations will be sent out by the NHS over the next week.
dr Nikki Kanani, GP and deputy head of the NHS Covid-19 vaccination program, said it was important for people to get their vaccination as “infections continue to rise”.
BA.2, while typically causing milder disease, is the most rapidly spreading variant to date.
It has triggered a second omicron wave which is believed to have peaked in March but has still left the UK with a very high prevalence.
Professor Paul Elliot of Imperial College London, leader of the REACT-1 Covid surveillance study, said greater intermixing and waning immunity were to blame for the surge.
He warned Britons who contracted the original Omicron virus over the winter could still get the newer BA.2 variant.
Detecting Covid twice or more is called reinfection and is defined as two positive tests at least 90 days apart.
With a high prevalence of the virus, someone is likely to be exposed to it at some point after recovery.
And as new variants emerge and become dominant so quickly, it’s possible they’ll be confronted with a strain they weren’t previously infected with.
Currently, BA.2 poses this risk to people who may have already received Original Omicron during the winter.
While this is possible, current data suggests that catching both Omicron strains is rare.
In a report by the UK Health and Safety Agency (UKHSA) in March, health chiefs said at least 43 double omicron infections had been sequenced out of 500,000 cases.
It is not clear whether these individuals were reinfected or whether they carried both strains at the same time.
Researchers at Denmark’s Statens Serum Institut, the country’s leading infectious disease agency, also found 47 cases of BA.2, following BA.1 infection out of 1.8 million cases.
They said: “Omicron BA.2 Reinfections, while occurring shortly after BA.1 infections, are rare,” adding that these cases “were mainly found in younger, unvaccinated individuals with mild disease.”
The World Health Organization said in February: “BA.2 re-infection after BA.1 infection 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 time period for which data are available.”
Omicron BA.1 is believed to offer some cross-protection against the BA.2 strain since they are of the same parentage.
The winter booster program, coinciding with the first Omicron wave, would also have boosted popular immunity.
Two weeks after a booster dose, efficacy against symptomatic disease is 63 percent for BA.1 and 70 percent for BA.2.
And many of those who received Omicron over Christmas would have had their booster shot only recently, given the 28-day wait after infection.
Experts concede that it is difficult to track and quantify reinfections caused by different Covid variants.
All reinfections are now counted by the government in daily numbers.
But not every positive Covid smear is sequenced the way the variant does.
This means individuals can be marked as “reinfected,” but it’s rarely possible to tell if they had two different strains.
As the recent wave has sent hospital admissions skyrocketing, NHS Medical Director Stephen Powis said: “Our frontline workers are working closely with social service providers to ensure patients leave hospital as soon as they are able , and hospitals have increased bed counts and added capacity to cope with the mounting pressure.
“Despite continued demand, staff remain focused on clearing the Covid-19 backlog and rolling out the NHS Spring Booster Scheme. So please report for your Covid shots and if you need NHS assistance use the NHS 111 online service.”
https://www.thesun.ie/health/8620330/warning-everyone-omicron-christmas-new-covid-risk/ Warning to all who caught Omicron at Christmas of new Covid risk