The new COVID-19 version – Omicron BA.4.6 – is a descendant of omicron’s BA.4 version.
London:
BA.4.6 is a subtype of the omicron COVID variant that is rapidly gaining traction in AmericaThe outbreak has now been confirmed in the UK,
latest briefing document The UK Health Protection Agency’s (UKHSA) COVID variant noted that during the week starting 14 August, BA.4.6 accounted for 3.3% of samples in the UK. It has since evolved to make up about 9% of sequenced cases.
Similarly, according to the Centers for Disease Control and Prevention, BA.4.6 now accounts for more than 9% of recent cases across America. Variants have also been identified many other countries Worldwide.
So what do we know about BA.4.6, and should we be worried? Let’s take a look at the information so far.
BA.4.6 is a descendant of omicron’s BA.4 variant. was BA.4 found out for the first time in January 2022 in South Africa and has since spread Worldwide with BA.5 Edition,
It is not entirely clear how BA.4.6 emerged, but it is possible that it could be a recombinant type, Recombination occurs when two different types of SARS-CoV-2 (the virus that causes COVID-19) infect the same person at the same time.
While BA.4.6 will be similar to BA.4 in many ways, it carries mutations in the spike protein, a protein on the surface of the virus that allows it to enter our cells. This mutation, R346T, has been observed in other forms and is linked to defense evasionWhich means it helps the virus avoid antibodies acquired from vaccination and prior infection.
Severity, infectivity and immune evasion
Fortunately, omicron infections usually cause less severe disease, and we’ve seen fewer deaths Compared to earlier variants with Omicron. We expect this to be applicable to BA.4.6 as well. In fact, so far there have been no reports that this variant is causing more severe symptoms.
But we also know that omicrons are subvariants more permeable Compared to the previous variants. BA.4.6 Appears Even better Compared to BA.5 on escaping the immune system, currently the major version. Although this information is based on a preprint (a study that is yet to be peer reviewed), other emerging data support this.
According to UKHSA briefing, early estimates suggest that BA.4.6 has a 6.55% relative fitness advantage over BA.5 in England. This indicates that BA.4.6 replicates more rapidly in the early stages of infection and has a higher growth rate than BA.5.
The relative fitness advantage of BA.4.6 is quite small Compared to BA.2 to BA.5, which was 45% to 55%.
University of Oxford have reported that people who received three doses of Pfizer’s original COVID vaccine produced fewer antibodies in response to BA.4.6 than BA.4 or BA.5. This is worrying because it suggests that COVID vaccines may be less effective against BA.4.6.
BA.4.6’s ability to evade immunity may however be addressed to an extent by new bivalent booster, which specifically target the original strain of SARS-CoV-2 as well as the omicron. Time will tell.
Meanwhile, a preprint study Indicates that BA.4.6 evades protection evusheldan antibody therapy designed to protect people who are immunocompromised and don’t even answer for COVID vaccines.
vaccination is important
The rise of BA.4.6 and other new variants is concerning. It shows the virus is still with us, and is mutating to find new ways to overcome our immune response. vaccination and past infections.
We know that people who have had COVID before can contract the virus Again, and this has been especially true for Omicron. In some casesSubsequent episodes may be worse.
But vaccination continues to provide good protection against serious illness, and is still the best weapon we have to fight COVID. The recent approval of a bivalent booster is good news. Beyond that, developing multivalent coronavirus vaccines Those that target multiple types can provide even more durable protection.
a recent study showed that a multivalent coronavirus vaccine administered via the nose elicited a strong immune response against the original strain of SARS-CoV-2 as well as two types of anxiety in a mouse model.
The new variants, including BA.4.6, are being closely monitored, as they may cause the next wave of the COVID pandemic. For the public, it will pay off to be vigilant and follow any public health measures to prevent the spread of a very contagious virus.
,Author:Manal MohammedSenior Lecturer, Medical Microbiology, University of Westminster,
,disclosure statement: Manal Mohamed does not work for, consult, own shares in or receive funding for any company or organization that would benefit from this article, and has disclosed no relevant affiliations beyond his academic appointment. Is.)
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