May 26, 2024

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COVID-19: Receiving one shot or two shot vaccines?

COVID-19: Receiving one shot or two shot vaccines?


COVID-19: Receiving one shot or two shot vaccines?  There are tree types of COVID-19 vaccines in China.  How should people choose vaccines?

  • SINOPHARM:  Inactivated vaccine
  • Fosun/BioNtech:  mRNA vaccine
  • Chenwei team: Adenovirus vector vaccine

Recently, the results of the interim analysis of the Phase III clinical trial of Adenovirus vector vaccine jointly developed by Academician Chen Wei and Cansino Biologicals showed that 28 days after a single injection of the vaccine, the vaccine’s protective efficacy against severe new coronavirus pneumonia was 100%, and the overall protective efficacy was 74.8%. Any serious adverse reactions related to the vaccine occurred.

COVID-19: Receiving one shot or two shot vaccines?
How to choose several COVID-19 vaccines in China? On the evening of the 9th, Bai Yansong connected with Shao Yiming, a researcher of the China Center for Disease Control and Prevention and a consultant of the WHO Vaccine R&D Committee.


■Is double-dose vaccination more advantageous than single-dose vaccination?

Shao Yiming: Double-dose vaccination may reduce the two-dose vaccination rate, but according to the intensity of the immune response it induces, it can be predicted that its future durability will be better than single-dose vaccination, so they have their own advantages and disadvantages.


■ Is the progress of the vaccine developed by Chen Wei’s team “slow”?

Both Sinopharm and Kexing’s vaccines have been vaccinated for a period of time. The vaccine of Academician Chen Wei’s team was the first vaccine to start clinical trials. Why was it “slow”?

Shao Yiming: The so-called “slow” is mainly due to the relatively good control of the domestic epidemic in China. We can only conduct Phase I and Phase II clinical trials when there are no risk groups and no virus attacks in China. But by stage III, there must be a high rate of new infections and a large number of cases in order to test the protective effect of the vaccine against the disease. China does not have this condition anymore, and can only carry out phase III clinical trials abroad.

This depends on the countries and institutions cooperating with China, their efficiency and conditions. In this case, we are limited by people.

■ How should China choose these new coronavirus vaccines in the future?

Shao Yiming: Although China has five technical routes, each vaccine is different in terms of effectiveness, safety and accessibility.

From the perspective of protection effect, the latest mRNA vaccine has a protection effect of more than 90%, and inactivated vaccines and viral vector vaccines have a range of 70% to 80%.

In terms of safety, medicine is an experimental science. Its safety and power depend on how many people have been tested and how long it has been tested. Inactivated vaccines have been used by humans for hundreds of years, so its safety is the highest.


(source:internet, reference only)

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