July 23, 2024

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Is the new COVID Omicron variant BA.4.6 more contagious?

Is the new COVID Omicron variant BA.4.6 more contagious?


Is the new COVID Omicron variant BA.4.6 more contagious?

Does the new strain BA.4.6 have stronger escape? It is now popular in Europe and the United States. 

The new coronavirus Omicron strain has undergone the reproduction and mutation of a series of strains such as BA.2, BA.4, BA.5, etc., and a new strain BA.4.6 has been derived.

The new strain is aggressive and contagious, and this variant has also been found in many other countries around the world.

The latest briefing by the UK Health Security Agency on new coronavirus variants states that in the week beginning August 14, the new coronavirus variant strain BA.4.6 accounted for 3.3% of UK cases. And gradually increased to about 9%.


Similarly, BA.4.6 currently accounts for more than 9% of recent cases in the United States, according to the Centers for Disease Control and Prevention (CDC), and has a strong tendency to replace the current mainstream strain BA.4/5.

How fast is this strain spreading? How should we protect?

According to the latest data from the U.S. Centers for Disease Control and Prevention (CDC), as of the week ended September 3, BA.5 was still the dominant strain in the United States at the time.

But in fact, there have been cases of infection with the new variant of Omicron BA.4.6 in the United States , which has also caused public health experts to worry that the new variant may change the trend of the epidemic again .

Is the new COVID Omicron variant BA.4.6 more contagious?As of September 15, 2022, the cumulative number of confirmed cases of the COVID-19 in the United States has reached 95 million, and the cumulative number of deaths has exceeded 1 million, with a fatality rate of 1.1%. Data sourceJohns Hopkins University CSSE COVID-19 Data




BA.4.6 spread to the United Kingdom, popular in the United Kingdom and the United States

The new coronavirus is always mutating. Since the emergence of the Omicron strain, from BA.1, BA.2 to the now popular BA.4, BA.5 and BA.2.12.1, and then to the later BA.2.75, the mutation of the strain seems to be endless.

Experts have previously issued an article saying that the Omicron substrain is completely different from the original strain of the COVID-19.

Many “children and grandchildren” have evolved, and while BA.4/5 are still making waves around the world, BA.4.6 has already entered the pandemic stage in the United States .

According to the latest information released by the US CDC, BA.4.6 is a new strain produced by the recombination of Omicron BA.4, which spread rapidly in the United States from late April to early May, initially in Iowa. , Kansas, Missouri and Nebraska, and patients infected with the new strain accounted for 10.7% of all cases in those areas.

At present, the virus strain has received extensive attention from the scientific community. BA.4.6 has now spread to 47 states in the United States.

Recently, it has been confirmed that it is spreading in the United Kingdom. This week starting from August 14, 2022, BA.4.6 accounted for the United Kingdom .

3.31% of reported COVID-19 confirmed infection samples.

Is the new COVID Omicron variant BA.4.6 more contagious?Briefing on Covid-19 Variants of Concern in the UK and Variants Under Investigation

According to the information from the US CDC, since the beginning of July 2022, the BA.4/5 variant strain of Omicron has been rampant, and the number of cases infected with the BA.5 variant strain accounts for 85.5% of the confirmed cases in the United States, and BA.4 accounts for 11.8%. %, maintaining a similar proportion in the last 4 weeks.

It is worth mentioning that the United States has experienced BA.1 and BA.2 infection waves before, and still has not been able to escape the invasion of BA.4/5.

Now that BA.4.6 is here, it has caused health officials to Pay close attention, because it has a stronger immune escape ability than BA.4, and it is predicted that it may become the main strain in the United States in the near future .





Propagation velocity and escape of BA.4.6

On 15 August 2022, BA.4.6 was identified as one of the strains of concern in the UK.

BA.4.6 has a mutation in a known antigenically significant site (S: R346T), and BA.4.6 has a clear proliferation advantage over the previously circulating BA.5 strain, which means the spread of the new strain will be faster.

The University of Oxford conducted a pseudovirus neutralization test on BA.4.6 and reported preliminary data to the Variant Technical Group.

The test showed that in the serum of subjects who received three doses of Pfizer’s BNT162b2 vaccine, the concentration of antibodies neutralizing BA.4.6 was reduced by 2 times compared with antibodies neutralizing BA.4 or BA.5, indicating that the COVID-19 vaccine is effective. T

he epidemic prevention effect of BA.4.6 may be poor.




How to prevent and control the new strain of BA.4.6

Recently, FDA-approved bivalent vaccines from Moderna and Pfizer (jointly developed with BioNTech) may be able to help people prevent the invasion of the new BA.4.6 strain to a certain extent, and the bivalent vaccine has been marketed as a booster shot .

This bivalent vaccine is designed through the dual antigens of the original new coronavirus and Omicron virus.

Global data on secondary infection shows that people who have been infected with the COVID-19 may be re-infected with subsequent mutated viruses, and even in some cases, the side effects of re-infection may be greater, so we should be more cautious in the face of constantly mutating viruses.

Is the new COVID Omicron variant BA.4.6 more contagious?


Currently, vaccination remains our best weapon against the coronavirus.

In addition to the recently approved bivalent and inhaled vaccines, the development of multivalent or broad-spectrum vaccines targeting multiple variants may provide us with more durable protection.

In addition, it is urgent to closely monitor new variants, including BA.4.6, as they could unleash the next wave of the Covid-19 pandemic globally.

For the general public, caution and compliance with public health measures are still required to prevent the indiscriminate spread of this still-contagious virus.







1. SARS-CoV-2 variants of concern and variants under investigation (publishing.service.gov.uk)
2. SARS-CoV-2 variants of concern and variants under investigation: technical briefing 44 (22 July 2022) (publishing.service.gov.uk)
3. Investigation of SARS-CoV-2 variants: technical briefings – GOV.UK (www.gov.uk)
4.Another new COVID variant is spreading – here’s what we know about omicron BA.4.6 (theconversation.com)

Is the new COVID Omicron variant BA.4.6 more contagious?

(source:internet, reference only)

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