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What does the emergence of Omicron mutants mean for double vaccination? | Coronavirus

The advent of Omicron has led to widespread speculation that it may be more resistant to the Covid-19 vaccine than existing variants, including Delta. But what does that mean for the average double vaccinated person?

All vaccines currently available in the UK work by training the immune system against coronavirus peplomer. This is the key used to infect cells by binding to the ACE2 receptor. Omicron has more than 30 mutations in this protein, 10 of which are in the so-called “receptor binding domain” (RBD). This is the specific part that latches on this receptor. There are two RBD mutations in the delta.

However, with all these changes, there are still regions (epitope) to which antibodies and T cells that proliferate in response to previous infections or vaccinations can respond.

“When you scribble a mutation in a picture of the crystal structure of a peplomer and relate it to all the major antibody activities we know, it looks kind of scary-of your important neutralizing antibody target. What’s the rest of your immune protection, as most have been shot into pieces? “Danny Altman, a professor of immunology at Imperial College London, said.

“Still, the sound from South Africa seems to say that it doesn’t seem to be harsh. People who go to the hospital are vaccinated, not vaccinated, as if vaccination was still purchased. I have not received it. [them] Some covers. “

Next, there are T cells. It is an immune cell that recognizes and attacks virus-infected cells and educates them about the viral risks facing antibody-producing B cells.

“We all think T cells can see the difference. [between variants], And because the T cell repertoire is much more impervious to it, it may also buy you some protection, “Altman said.

The question is how much protection is it? People who are double-jabed can be infected with the delta variant and can actually be infected, but this is most likely to occur. One third Than if they weren’t vaccinated.More importantly, vaccinated individuals are roughly 1/9 chance To die if they become infected.

Professor Paul Morgan, an immunologist at Cardiff University, says that while the chances of getting infected with Omicron appear to be even higher: [of immunity] This is the most likely result.

“A virus cannot lose all epitopes on its surface, because it causes the spike protein to fail. Therefore, antibodies made against previous versions of the virus or against vaccines. And some T cell clones may be ineffective, while other antibodies and T cell clones remain effective. “