Studies needed into the long term effectiveness of mRNA vaccines as opposed to AstraZeneca .... essentially, Pfizer gets rid of the body's instruction on how to fight the virus, AZ teaches the body how to fight the virus.
The Pfizer vaccine uses genetically engineered messenger RNA, which instructs the body’s cells to make proteins found on the surface of the COVID-19 virus. That prompts a response from the immune system. The cells also break down the instructions and get rid of them, which Dr. Walker said could explain why the effectiveness fades.
The AstraZeneca vaccine uses genetic material from the COVID-19 virus and puts it in a harmless virus. Once injected, the viral vector teaches the body’s cells how to make the COVID-19 proteins, which trigger the immune system.
“These vaccines are just doing very different things,” she said. “They may be having the same protection overall, but how they are getting to that protection is quite different and we need to think about that long term.”
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