new coronavirus continues to mutate, and the Omicron mutant strain BA.4 / BA.5 has become the dominant virus strain in many regions, while the durability and upgrade of vaccine has attracted more attention.
On August 15, the British government approved a new-generation vaccine developed by Modena Company as a booster for mass vaccination.
This vaccine, which was first approved as a booster in the UK, is called Spikevax, and it is called a bivalent vaccine (bivalent vaccine). Austrian strain "BA.4/BA.5 can also provide strong immune protection.
One stone kills two birds
Moderna’s official website data shows that , the test results on 437 people show that the upgraded version of the vaccine is safe, and it is available for both the original mutant virus and the newer strain of Omicron Better immune protection, but the same side effects as the original version of the vaccine. The
data show that people who use the bivalent vaccine as a booster have a high level of antibodies in their blood and a stronger immune protection. Moderna Spikevax uses the original new crown strain and the Omicron variant strain BA.1 that appeared in early 2022, but the test results show that it is also effective against the Omicron subtype strains BA.4 and BA.5. Provides greater protection than older vaccines. There was no evidence that bivalent vaccines performed differently in stopping the spread of the virus. The British " Daily Telegraph " quoted Darius Hughes, general manager of Moderna's UK branch, saying that the design of Moderna's mRNA vaccine provides room for adding other strains or variants in the future , can be handled flexibly, adding new strains or mutant strains on the basis of retaining the original virus strains. He explained that the updated vaccine contains the genetic code of the original Omicron strain BA.1, which also applies to BA.4 and BA.5. Modena hopes to develop a bivalent vaccine combined with influenza vaccine by next winter: the new crown-influenza vaccine, and develop a vaccine against new crown, influenza and respiratory syncytial virus (RSV) by the winter of 2024-2025 "Three-in-one" vaccine. Other pharmaceutical companies are also developing vaccines against Omicron and its subtypes, including Pfizer , China Kexing and Sinopharm.
"Austrian strain": BA.4 and BA.5 are more "cunning"
New coronavirus variants and their subtypes have enhanced immune escape ability, while people's immunity has decreased, plus people who have never been infected with new crown (UK population 20% of the population) have a higher probability of infection, which has contributed to a new wave of epidemics characterized by repeated infections. Of particular concern are the newly emerged Omicron subtype strains BA.4 and BA.5.
The New England Journal of Medicine published a research report stating that BA.4 and BA.5 can "basically escape" the immune protection of vaccination or previous infection, that is, they have a strong ability to escape immune suppression.
A study in the journal Science also showed that the original Omicron variant acts like a "stealth virus", which makes the human immune system less vigilant and discerning against later subtype variants reduce. This is what scientists call "immunoblotting."
Although the number of severe cases requiring hospitalization has not increased proportionally in the recent outbreak, infection still disrupts and inconveniences daily life, poses additional risks for those with underlying medical conditions or immune vulnerable populations, and may also increase evolution The risk of becoming a "new crown".
There is no indication that the newest subtype variant is more dangerous than the original Omicron, but it is impossible to say for sure at this time, as only laboratory and animal research data are available.
A Japanese study showed that BA.4 and BA.5 are easier to grow in lung cells. The symptoms of the hamster infection were more severe than those of the early new coronavirus infection.
In terms of severity, the new coronavirus and its descendant variants may look more like flu, but the difference, at least for now, is that flu only has one high season each year.
