Is there any research or guidance regarding the vaccines for those of us who already had it?


A: Those who have had COVID19 are recommended to receive the vaccine.

Data from the Pfizer and Moderna vaccine trials demonstrated safety in participants that have had COVID19 previously. Scientists are hopeful that the vaccine will offer a higher level of protection than immunity to natural infection.

Although the Pfizer and Moderna vaccine excluded participants with a known history of COVID-19, a number of participants on both trials were found to have baseline antibodies against SARS-CoV2- indicating a prior infection. There were 1125 participants on the Pfizer trial and 675 participants on the Moderna trial with baseline antibodies. There were no safety signals from having a prior SARS-CoV2 infection. Moderna’s trial noted that people with prior COVID-19 infection had decreased adverse events.

One of the reasons why the vaccine is recommended is because immunity to natural SARS-CoV2 infection is variable. Antibodies after COVID19 infection can vary 200 fold! Some people may have no circulating antibodies and very little immunity, while others can have high levels of antibodies. Even if someone has circulating antibodies, they may not have antibodies that are neutralizing- which stop the virus from entering the cells in our body.

Immunity may only last several months and it is possible to be re-infected.

The CDC Advisory Committee on Immunization Practices (ACIP) recommendation is for people that have a history of previous SARS-CoV2 infection to be vaccinated. Because there may be some immunity to SARS-CoV2 for 3 months post infection, people may decide to delay vaccination until 3 months post-infection if they want. Testing for antibodies is not recommended for vaccine-decision making.

If someone has a current SARS-CoV2 infection they should wait until recovered to receive a vaccination.

On a personal note, this nerdy girl is grateful that her medical provider spouse is receiving the vaccine although he has a history of viral infection. It will protect him and hopefully serve as another line of defense to prevent the virus from traveling home.

ACIP clinical considerations for Pfizer vaccine

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