A doctor monitors a Covid-19 patient in the Covid-19 intensive care unit of a community hospital in Germany on April 28, 2021.
RONNY HARTMANN | AFP | beautiful pictures
LONDON – Infections are on the rise in Europe, with an increasing number attributed to the prevalence of a “stealth” sub-variable of the omicron strain.
Covid cases have increased dramatically in the UK in recent weeks, while Germany continues to record a record high number of daily infections with more than 250,000 new cases per day. Elsewhere, France, Switzerland, Italy and Netherlands are also seeing Covid infections start to rise again, aided and abetted by the easing of Covid measures and the spread of a new subvariable of omicrons, known as BA.2.
Public health officials and scientists are closely monitoring BA.2, has been described as a “stealth” variant because it has genetic mutations that can make it difficult to differentiate from the delta variant using PCR testing, from the original omicron variant, BA.1.
The new sub-variant will be the latest in a long line to emerge since the pandemic began in China in late 2019. The omicron variant – the most contagious to date – has surpassed the delta variant. , which itself replaced the alpha variant – and this is not even the original strain.
Now, Danish scientists believe that the subvariable BA.2 is 1.5 times more capable of traveling than the original omicron strain and is surpassing it. Variant BA.2 is now responsible for more than half of new cases in Germany and accounts for about 11% of cases in the US.
This number is expected to increase further, just like in Europe.
“It is clear that BA.2 is more contagious than BA.1 and this, combined with the easing of mitigation measures and the weakening of immunity, is contributing to the current increase in infections. “, Lawrence Young, professor of molecular oncology at the University of Warwick, told CNBC on Monday.
“BA.2’s increased infectivity has exceeded its ability to compete with and displace BA.1, and we are likely to see similar waves of infection as other variants enter the population. “
As long as the virus continues to spread and replicate, especially in unvaccinated populations or where vaccine immunity is waning, “it will create new variants and mutations.” This body will remain a constant threat even for countries with vaccination rates,” Young noted. “Living safe with Covid does not mean ignoring the virus and hoping it will go away forever. .”
What do we know about BA.2?
The BA.2 variant is being closely monitored by the World Health Organization and similar public health authorities at the national level, including the UK Health Security Agency (UKHSA), says the variable. This subtype is “under investigation” but is not of concern.
However, WHO acknowledged in a statement last month that “the proportion of reported sequences designated BA.2 has increased compared with BA.1 in recent weeks.”
Preliminary data suggest that BA.2 is more likely to cause infection in household contacts, when compared with BA.1. According to a British parliamentary report published last week.
Hospitalizations have also increased in some European countries due to a surge in Covid infections in recent weeks, but deaths are still far below previous peaks thanks to widespread vaccination. -ask for.
UKHSA performed a preliminary analysis comparing the efficacy of vaccines against symptomatic disease for BA.1 and BA.2 infections and found that the level of protection was similar, with efficacy on up to 77% immediately after booster injection, although this should decrease over time. .
‘Growth advantage’
WHO also notes that BA.2 differs from BA.1 in its genetic sequence, including some amino acid differences in the mutant protein and other proteins that may give it an advantage over the original omicron. head.
“Studies are underway to understand the reasons for this growth advantage, but early data suggest that BA.2 appears to be more transmissible than BA.1, which remains the most commonly reported omicron subroute. This transmission difference appears to be much smaller than, for example, the difference between BA.1 and Delta,” the WHO said last month.
WHO added that early studies show that anyone who has been infected with the primary omicron variant is likely to protect against reinfection with its BA.2 subvariant.
Dr Andrew Freedman, infectious disease reader at Cardiff Medical School, told CNBC he doesn’t think we need to worry too much about BA.2, despite the fact that it’s a bit more contagious.
“I suspect the increased number of cases is related to a number of factors including BA.2, easing of restrictions and more social inclusion, less mask wearing and some decline in immunity. epidemic for both previous infections and vaccinations, especially in those who received early boosters,” he said.
“There has been an increase in hospital admissions testing positive for Covid in the UK, but many of these cases are random and there has not been a parallel increase in the number of deaths.”
Increasingly popular
The UK and the rest of Europe have acted as a herald for the US at some point during the pandemic, according to a WHO statement two years ago. especially when it comes to the proliferation and spread of new Covid variants that have emerged and subsequently replaced previous strains of the virus.
This makes the emergence and growing prevalence of the BA.2 variant a point of concern for the United States, where cases have recently dropped to the lowest levels warranted.
According to data from the US Centers for Disease Control and Prevention, some parts of the US are seeing increasing numbers of BA.2-related infections, especially in New York.
Elsewhere, China is currently facing The worst Covid-19 outbreak since the peak of the pandemic in 2020.
It is unclear whether BA.2 contributed to the latest wave of cases, although a prominent infectious disease expert in China told Caixin news agency that much of the current outbreak is being driven by the subvariable BA.2.
The UK data certainly illustrate the growing popularity of BA.2. Sequential data from February 27 to March 6 showed that 68.6% of cases were omicrons of the BA.2 line, with only 31.1% of omicrons of BA.1.
