Amicron vaccine It has appeared in immunogenicity to the extent of current booster vaccines.

In the coming days, the people of the United States and the Kingdom of England will be among the first nations to receive a new generation of the Covid-19 vaccine (Amicron vaccine). We hoped that vaccines developed based on different strains of Amicron and SARS-CoV-2 would provide significantly greater protection than older vaccines based on the virus strain that emerged in 2019; But analyzes show that booster doses of older vaccines offer the same level of protection as doses of the micron-specific vaccine — especially when it comes to hospitalizations.

The immunogenicity of the Amicron vaccine was less than expected!

Amicron’s new vaccination, approved in the United States and the United Kingdom, shows protection similar to current booster vaccines. In this regard, John Moore, a vaccine development scientist in John and Sanfred Weill College of Medicine, Cornell University New York City, which was not involved in the modeling, said:

“These vaccines are not super protective compared to what you were getting two weeks ago or a month ago.”

Moore argues that regulatory agencies in the United States and the United Kingdom should have investigated the potential impact of new vaccines before approving them.

On August 15, the United Kingdom became the first country to approve one of the new “bivalent” vaccines, based on the original Omicron BA-1 strain found in Wuhan, China, and soon to be officially approved. They start vaccinating it. Apparently, the United States government has also given the green light to similar bivalent vaccines.

Appropriate large-scale trials have shown that first-generation Covid-19 vaccines reduce the risk of disease by more than 90%; But such studies have occurred by randomly testing tens of thousands of people to receive a vaccine or a placebo and then monitoring these people to see who gets infected; But in 2022, it is no longer practical, possible or ethical.

Instead, the developed Covid-19 vaccines have been tested in smaller clinical groups, and to gauge their effectiveness, the developers have typically measured the participants’ immune responses, specifically the levels of “neutralizing” antibodies that block the infection, and compared them to people who received another dose.

Most of these clinical trials are based on updated vaccines – not only O-Micron Bell, which showed greater effectiveness on older strains such as beta compared to the original vaccine. In this regard, Stephen Hog, the president of Moderna Company, said:

Dramatically, this booster vaccine is superior!

Earlier, on June 8, when the company presented its results about vaccines based on the B.A. strain. 1 also used such an expression. It seems that we should look at the statements of pharmaceutical companies with suspicion!

At the University of New South Wales in Sydney, Australia, a team led by data modeling mathematician Deborah Cromer gathered all the clinical trial results of the updated vaccines available to researchers in an effort to make sense of the results of vaccines like the one Moderna has offered.

Also, they are studies on The effectiveness of the fourth dose of the vaccine based on the main strain of the Covid-19 virus. According to their analysis, both types of vaccine significantly increased antibody levels, but the updated versions produced antibodies that were on average 1.5 times higher than the older SARS-Cov-2-based vaccines. Cromer says in this regard:

We’re not talking about chump change!

Read more: The new strain of Corona is spreading widely; What do we know about BA.4.6?

The lower hospitalization rate of people with Amicron vaccine

Studies show that higher levels of antibodies cannot work better against Covid-19. But it was still not clear how effective the updated vaccines would be in clinical trials.

To determine this, Cromer’s group developed a functional model in which Ms. Miles Davenport, an immunologist at the same university, and her colleagues were able to relate the effectiveness of the main Covid-19 vaccines to the level of antibodies in people. In fact, the model showed that most of the efficacy of updated vaccines is similar to a booster dose of older vaccines.

For example, in communities where half of the population has acquired partial immunity to Covid-19 infection through vaccination or previous infection, a booster dose of an O-micron strain-based vaccine increases the level of immunity by 90%, compared to booster doses Older vaccines show 86% immunity. However, for protection against severe disease, the difference in immunogenicity was less than 1%.

At a general level, injections of updated vaccines can make sense. Cromer’s group estimated that a booster campaign based on updated vaccines had an average of 8 fewer hospitalizations than old vaccines per 1,000 people.

He added:

If it means keeping hospital beds empty and preventing severe infections, that’s reason enough to recommend updated boosters.

The relative advantages of enhancers based on new strains can appear even more effective; Suppose a new strain comes and suddenly reduces the existing level of immunity; As it happened in December 2021 with the advent of O-micron – and the same thing may happen again. Based on this scenario, Cromer says, O-micron-based vaccines could therefore provide much better protection than older vaccines.

Read more: New mutations of Corona are more contagious than before and resistant to vaccines

Long-term benefits of Amicron vaccine

When the campaign Booster dose Starting in the US, different Omicron vaccines will be used than those approved in the UK. In June, a task force recommended that the US Food and Drug Administration (FDA) require companies to develop bivalent vaccines based on the main strain and types BA4 and BA5 of the coronavirus – which have protein sequences are the same – instead of producing bivalent vaccines. Such as the BA1 bivalent vaccine that was tested by Moderna, Pfizer-Biontech and other drugmakers because it was hoped that by better adapting to the circulating strains, the vaccines would become more effective.

But Cromer’s dig shows that the differences may be small; Even booster vaccines based on beta and delta types should provide immunity against BA4 and BA5 strains as well as other strains. For example, bivalent vaccines containing the original vaccine were no more effective than vaccines based solely on a newer variant.

For these reasons, Cromer says, the FDA’s decision to reject the BA1-based booster was unlikely, especially as SARS-CoV-2 continues to evolve. Cromer also added that it doesn’t seem likely [همه شمول بودن یک واکسن] Show that a significant improvement in the effectiveness of the booster vaccine can be made.

Is it a waste to distribute the special vaccine for Amicron?

Dean Follman, a statistician at the National Institute of Allergy and Infectious Diseases in Bethesda, Maryland, says that even marginal benefits BA4 and BA5 based vaccine It may be enough to justify their public offering. “Probably somewhat better. Much better – maybe not.” Additionally, he said the main message of the analysis should be that any boosted Covid-19 vaccine is effective and good.

Other scientists are questioning the decision to pursue various types of enhancers, that too in a situation where the benefit is very small. In this regard, Moore worries that people will be misled into thinking that updated vaccines are more effective than existing ones, leaving themselves more vulnerable to infection.

Paul Offitt, a vaccine researcher at the Children’s Hospital of Philadelphia in Pennsylvania who was one of two FDA advisory committee members who voted against updating Covid-19 vaccines, says Cromer’s analysis vindicates their skepticism.

“If the Amicron-specific vaccine is no more effective than current vaccines, then why distribute it? That is if you will have very little effect on the occurrence of severe disease.

In the long term, it may make sense to develop species-based vaccines, Cromer says, but the idea that they must exactly match the circulating virus strains is unrealistic — and counterproductive when we already have highly effective vaccines available. we will get He added:

The most important booster is the vaccine you actually receive.

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Source: Nature