March 22, 2023

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Elderly people over 80 years old need two doses of COVID-19 vaccine

Nature: Elderly people over 80 years old need to be vaccinated with two doses of the COVID-19 vaccine to achieve the best protection effect


Elderly people over 80 years old need two doses of COVID-19 vaccine. Worldwide, the most widely vaccinated COVID-19 vaccines are the two earliest FDA-approved mRNA vaccines.

Both mRNAs require two doses to provide better protection. However, for the elderly over 80 years old, there are few vaccine research data, and the elderly are high-risk groups of COVID-19. Therefore, it is necessary to take specific measures to improve the response of the elderly to the vaccine.


On June 30, 2021, researchers from the University of Cambridge and other institutions in the United Kingdom published a research paper entitled: “Age-related immune response heterogeneity to SARS-CoV-2 vaccine BNT162b2” in the top international academic journal Nature.


The study found that about half of people over the age of 80 can achieve optimal virus neutralization only after a second shot of Pfizer-BioNTech’s mRNA vaccine. The results of this study have important implications for the global vaccination plan.


Elderly people over 80 years old need two doses of COVID-19 vaccine


The research team compared the immune responses of 80 elderly and 60 young healthcare workers after vaccination.


Three weeks after the first injection of Pfizer-BioNTech’s mRNA vaccine, compared with the young group, the elderly group over 80 years old had a lower proportion of producing sufficient neutralizing antibody titers.


After the first injection, compared with the younger group, the elderly group had a worse ability to neutralize the mutant strains that are worthy of attention, including Alpha (B.1.1.7) and Beta (B.1.351) mutants.


However, after the second injection, the neutralizing antibody responses of all subjects were comparable.


Vaccines are still the top priority for the prevention and control of the COVID-19 epidemic, but clinical trials that promote vaccine development rarely recruit people over 80 years old. The results of this study may help explain severe infections reported after only one injection.


Due to the tight supply of vaccines, some countries have decided or intend to extend the interval between two injections from 3 weeks to 12 weeks, but the author of the paper issued a warning. The elderly are high-risk groups, and it is necessary to adopt specific methods to enhance the vaccine response, especially in areas where vigilant variants are spreading. In addition, if the vaccine delay strategy leads to unsatisfactory vaccination effects, or to provide soil for the emergence of new vaccine-resistant variants.


(source:internet, reference only)

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