Covid-19: Is the UK heading for another omicron wave?BMJ 2022; 376 doi: https://doi.org/10.1136/bmj.o738 (Published 18 March 2022) Cite this as: BMJ 2022;376:o738
After several weeks of decline, global covid-19 case numbers are rising again. Parts of Asia such as Hong Kong are experiencing huge and deadly surges of the virus.1 In the UK, cases and hospital admissions, which had been falling since the omicron peak in January, are now increasing.
The latest figures from NHS Test and Trace show that in England a total of 323 032 people tested positive for SARS-CoV-2 between 3 and 9 March 2022, an increase of 55.5% from the previous week.2
The Office for National Statistics, which collects its own separate data, has reported that in the week ending 12 March around 1 in 20 people in England were infected with the virus—up from one in 25 the week before.3 In Wales an estimated one in 25 people had covid-19 during that week, up from 1 in 30 people the week before. In Northern Ireland there was a slight decrease from one in 13 the week before to one in 14, and in Scotland the rate rose from one in 18 to one in 14.4
Latest data from NHS England show a similar trend with hospital admissions. While daily covid-19 admissions had been declining—from a peak of 2317 on 29 December 2021, down to 786 on 25 February 2022—they have now started to rise again. Since 28 February daily admissions to hospitals in England have been almost consistently above 1000, and on 13 March the number hit 1555.5
Researchers believe one of the main factors behind the rising cases and admissions is BA.2, a sublineage of the omicron variant.
The original SARS-CoV-2 omicron variant, now known as BA.1, hit the UK hard over winter 2021-22, causing a big wave of infections and putting huge pressure on hospitals. But in late January 2022 it was noted that a second variation of omicron, BA.2, was starting to spread around the world. BA.2 is significantly more transmissible than BA.1, although it is still not clear whether it causes more severe disease.6
Speaking to The BMJ, Eric Topol, professor of molecular medicine at the Scripps Research Institute in California, said, “I would attribute this to the ‘BA.2 triad.’ The variant has 30% more transmissibility than BA.1, but spread has been further enhanced by relaxed mitigation measures and waning of vaccine immunity. It’s all intertwined and clearly going to lead to more widespread surges, including in the US.”
Topol warned that this would now further prolong the pandemic and could even provide “yet another path to a new variant in the months ahead.”
Colin Angus, senior research fellow at the University of Sheffield’s school of health, also identifies BA.2 as the key factor. He told The BMJ, “The recent rise in covid-19 infections, which is being driven by the emergence of the more transmissible BA.2 variant of omicron, has led to increases in the number of people in hospitals in England with covid-19 in all age groups and across all regions of the country.”
Angus highlighted two factors that he thinks will determine whether the rise in cases and admissions is a “small bump in the road or a full blown second omicron wave.” The first is how much people have relaxed their behaviour since covid restrictions were removed in the UK at the end of February. The second is the extent to which BA.1 infection provides protection against BA.2.
“I think the jury is still out on this last question, and I’ve certainly heard quite a few anecdotal reports of people coming down with covid recently for the second time in a few months, but there is some evidence to support the idea that such reinfections should be relatively rare,” he said. “I’m cautiously optimistic that we might start to see a downturn in cases soon, but I think there’s still a lot of uncertainty around what will happen in the coming weeks.”
Some researchers have also suggested that the rise in cases could be related to waning immunity.7
Although more than two thirds of the UK population aged 12 and older have received a booster dose of vaccine, and 85% have had at least two doses,8 many older and vulnerable people had their last dose some months ago.
Additional booster doses are now being discussed in many countries. In the US both Pfizer and Moderna have now asked the Food and Drug Administration for emergency authorisation of a second booster dose of their covid vaccines, with Pfizer requesting it for over 65s,9 while Moderna has gone further by requesting it for all adults.10
Despite the rise in cases the UK government, which has already removed nearly all covid related control measures, has also been slowly dismantling its pandemic systems and removing funding from key studies that track covid-19, including REACT-1 (which tracks community transmission) and the Zoe covid study (which tracks symptoms).1112 This has raised serious concerns over the UK’s ability to respond to the virus.
Simon Clarke, associate professor in cellular microbiology at the University of Reading, said that although he understood that the government was “keen to stop spending on expensive testing infrastructure” and that people were tired of isolation requirements, “we cannot simply wish away this coronavirus.”
He warned, “The government must be careful not to dismantle all the systems which have allowed UK planners to stay ahead of the omicron wave through a successful vaccination drive.”
James Naismith, director of the Rosalind Franklin Institute and professor of structural biology at the University of Oxford, added, “At this level of prevalence and the decision not to halt the spread, the most likely outcome is that almost everyone who is susceptible is going to be infected. For the UK, my main concern is for the vulnerable for whom this disease is serious and for those whose lives will be blighted by long covid.
“Every effort must be made to triple vaccinate as many people as possible, quadruple vaccinate the most vulnerable, and make available antivirals.”
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