Thread by @DocJeffD

FDA will review data for authorizing the 1st vaccine to prevent COVID-19 tomorrow. The vaccine is made with an exciting new technology, mRNA. I'm sharing some information from @CDCgov about mRNA vaccines & how we got here so quickly without compromising effectiveness & safety. 1/

What is mRNA? It's a "molecular blueprint" for a cell to make proteins. In this case, mRNA instructs our own cells where the vaccine is injected to make a protein found on the surface of the SARS-CoV-2 virus. Our immune system then develops a protective response against it. 2/

In contrast, most vaccines use weakened or inactivated versions or components of a virus or bacteria to stimulate the body’s immune response. Weakened live virus vaccines like MMR & varicella work by replicating in our cells using the vaccine virus' mRNA. 3/

mRNA vaccines do not contain a virus or create a virus & mRNA does not get into the nucleus of our cells or into our DNA or our genetic material or persist in our bodies. mRNA vaccines cannot cause an infection. Enzymes in the body break down mRNA after the vaccine works. 4/

mRNA & other COVID-19 vaccines were developed more rapidly than previous vaccines because several steps in the testing & manufacturing of vaccine were done simultaneously instead of one after the next. But no safety or effectiveness study steps were skipped or shortened. 5/

COVID-19 mRNA vaccines will go through the same rigorous safety assessment as all vaccines before they are authorized or approved for use in the United States by the Food and Drug Administration. This includes large clinical trials and data review by a safety monitoring board. 6/

Guidelines from the Food and Drug Administration (FDA) on testing of Covid-19 vaccine candidates indicate that no compromises will be made when it comes to evaluating safety and efficacy. 7/ fda.gov/regulatory-inf…

A difference btwn the 1st COVID-19 vaccines & earlier vaccines is we have less experience initially to know if rare side effects may appear when many more people are vaccinated. This trade off is outweighed by the benefits of effective vaccine against COVID-19 sooner vs later. 8/

There will be multiple systems in place to continue to monitor vaccine safety even after a vaccine is approved. But most vaccine side effects appear during the required clinical trial study time frame & will be evaluated before authorization. 9/n cdc.gov/coronavirus/20…

Here's a good info site from CDC. 10/10
cdc.gov/coronavirus/20…