Is omicron subvariant BA.2 to blame for rising Covid cases?
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On April 28th, 2021, a doctor examines Covid-19 patients in the intensive care unit at the German community hospital.
RONNY HARTMANN | AFP | Getty Images
LONDON — Covid cases are rising in Europe, with an increasing number being attributed to the prevalence of a “stealth” subvariant of the omicron strain.
Covid cases have risen dramatically in the U.K.In recent weeks, Germany has been experiencing record-breaking daily infection rates with more than 250,000 cases per day. Elsewhere, France, Switzerland, Italy the NetherlandsWe are also witnessing Covid infections rise again. This is being facilitated and encouraged by relaxation of Covid precautions and the spreading of an omicron subvariant, called BA.
Both scientists and officials in public health are monitoring BA.2 closely. which has been described as a “stealth” variantIt has genetic mutations which could make it more difficult to identify from the delta variant via PCR tests. This is in contrast to BA.1.
This new subvariant is the latest to be discovered since the outbreak in China at the end of 2019. The omicron variant — the most transmissible strain so far — overtook the delta variant, which itself supplanted the alpha variant — and even this was not the original strain of the virus.
Now, Danish scientists believe that the BA.2 subvariant is 1.5 times more transmissible than the original omicron strain, and is already overtaking it. Over half the cases are now in Germany, while the BA.2 subvariant accounts for around 11% in the U.S.
This number is likely to increase further as in Europe.
CNBC was informed Monday by Lawrence Young of Warwick University’s molecular oncology department. “It is clear that BA.2 can be transmitted more than BA.1” Young said.
“The greater infectiousness of BA.2 outcompetes and replaces BA.1, so we will see similar outbreaks as other variants in the population.”
Young stated that the virus will continue to spread, replicate and multiply, especially in under-vaccinated populations or areas where vaccine-induced immunity has decayed. Young also noted that “it will create new variants, and these will be a constant threat even for countries with high vaccination rates.” Living safely with Covid does not mean that you should ignore the virus or hope it will disappear forever.
What can we learn about BA.2
The World Health Organization is closely monitoring the BA.2 variant, as well as similar national public health agencies such the U.K. Health Security Agency (UKHSA), which have said that the subvariant was “under investigation”, but not of concern.
The WHO still acknowledged last month in a statement that the proportion of sequences reported as BA.2 had been rising relative to BA.1 over recent weeks.
BA.2 appears to have a slightly higher risk of causing infections in households than BA.1. Although it is not known if the BA.2 variant can cause more serious illness, or an increase in the likelihood of hospitalisation, initial data suggests that this variant may be a little more likely to do so. However, further research will need to verify the findings. a U.K. parliamentary report published last week.
In many European countries, hospitalizations are on the rise as Covid infection rates have increased in the last weeks. However, deaths have not fallen to previous highs due to widespread vaccination coverage.
UKHSA performed a preliminary assessment to compare vaccine effectiveness against symptoms for BA.1 or BA.2 infections. It found similar levels of protection with an efficacy up to 77% shortly after booster shots, but this decreases over time.
‘Growth advantage’
WHO also pointed out that BA.2 is different from BA.1 regarding its genetic sequence. This includes amino acid differences in spike protein, which may give BA.2 an advantage over BA.1.
Although research continues to investigate the reason for the growth advantage, preliminary data indicate that BA.2 is inherently more transmissible as BA.1, the current most prevalent omicron lineage. According to the WHO, this difference in transmissibility is much less than that between BA.1 or Delta.”
According to the WHO, initial research suggests that people infected by the original Omicron variant have strong immunity against infection with subvariant BA.
CNBC spoke with Dr Andrew Freedman from Cardiff Medical School about infectious diseases. He said that he does not think there is any need to worry too much about BA.2, even though it’s slightly more contagious.
He stated that “I believe the increasing number of cases can be attributed to several factors such as BA.2, the relaxing of restrictions and greater social mixing, less mask-wearing, and some waning in immunity from previous infections and vaccinations, especially for people who were given boosters earlier on.”
Although there have been some increases in hospital admissions for Covid testing in the U.K. however, many of these were not related to an increase in deaths.
Tolerance is on the rise
Both the U.K. (and the rest of Europe) have served as bellweathers for the U.S. during the two-year pandemic. It is especially concerning the spread and growth of new Covid variants, which has supplanted earlier strains.
It is this that makes the rise and spread of the BA.2 variation a matter of concern for the U.S.
Data from the U.S. Centers for Disease Control and Prevention shows that there are already increasing numbers of cases of infection linked to BA.2, in particular New York.
China faces other challenges. worst Covid-19 outbreak since the height of the pandemic in 2020.
However, a Chinese infectious disease specialist is well aware of the possibility that BA.2 may have contributed to the recent wave of cases. told news outlet CaixinThe BA.2 subvariant is responsible for a large part of the outbreak.
BA.2 is becoming more common in U.K. data. Data sequenced from February 27 through March. 6, found that 68% of the cases had omicron lineage B.2, while only 31.1% were Omicron.1.
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