June 27, 2022

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2nd dose of COVID-19 vaccines is necessary due to mutant strains escaped

The new coronavirus mutant strain escaped the humoral immunity, but failed to escape the cellular immune response; the second dose of vaccination is necessary

 


2nd dose of COVID-19 vaccines is necessary due to mutant strains escaped. In the life-and-death game between COVID-19 and humans, in addition to the first generation of COVID-19, which is extremely toxic and contagious, it also has a scary ability: mutation.


Among the currently known mutant strains, the British mutant strain B.1.1.7 and the South African mutant strain B.1.351 are the two most troublesome mutant strains for scientists. The British mutant strain is more transmissible and soon became the mainstream strain in most European and American countries; while the South African mutant strain has a higher ability to avoid the immune response that has been established by humans, known real-world data Show: AstraZeneca vaccine is almost ineffective against South African mutant strains.

The ultimate weapon for mankind to deal with the new coronavirus is a vaccine.

Different vaccines have different protective effects, and the protective effects produced by different vaccination methods of the same vaccine are also different. This is mainly related to the immune response induced by the vaccine.

On May 25, 2021, Erasmus MC of the Netherlands published an important article in Science Immunology, stating for the first time that the new coronavirus mutant strain escaped humoral immunity in patients and vaccinators during recovery from COVID-19, but did not escape T cell response .

This study analyzed the humoral and cellular immune responses of 23 medical staff who had previously been infected and 121 BNT162b2 mRNA vaccination to wild-type new coronavirus and to B.1.1.7 and B.1.351 mutant strains.


Studies have found that the second vaccination can achieve a high level of humoral and cellular immune responses in all individuals.

The vaccine-induced antibodies cross-neutralized the mutant strains B.1.1.7 and B.1.351, but the neutralizing ability and Fc effect against B.1.351 were reduced by 2 to 4 times compared with other viruses.

However, the study observed no difference in the response of CD4 T cells to the response of mutant strains.

This study shows that, on the one hand, it is of great significance to develop a second-generation COVID-19 vaccine that also induces cellular immunity; on the other hand, it is very important to complete two doses of vaccination. It may even be necessary to intensify the vaccination after a period of time.

2nd dose of COVID-19 vaccines is necessary due to mutant strains escaped

 

 

 

2nd dose of COVID-19 vaccines is necessary due to mutant strains escaped

(source:internet, reference only)


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