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Antibodies Vaccine

Vaccine after COVID19 infection

If you’ve previously had COVID19, you still need the vaccine.

Let me repeat for the back to hear.

If you’ve previously had COVID19, you still need the vaccine. Even if you had a positive antibody test.

Studies have shown that ~10% of people who recovered from COVID19 have weak antibodies and they wean off after a while (it looks like about 90 days). When the antibodies wean off, you will get reinfected if you come in contact with the virus again. And you won’t have protection. (By the way, this is what’s causing the small rate of reinfections).

Unfortunately, we can’t accurately predict who those 10% of people are. The only thing we know is that typically mild infections don’t mount a strong or lasting immunity to the virus. The worse the first infection, the stronger the immune response will be.

So, because we don’t know whether you land in the 10% category, everyone needs a vaccine. Vaccines provide you with the “perfect formula” needed to have a strong antibody response so the virus doesn’t overwhelm your body. Everyone will be on the same playing field.

Strong “natural antibodies” (ie not from a vaccine) have shown to last up to 8 months. But that’s because these studies were only 8 months long. As I’ve mentioned many times before, we are expecting antibodies to last 1-2 years because that’s how long COVID’s cousins last (SARS & MERS). Not enough time has passed to know for sure. Also, we won’t know how long immunity produced by vaccination lasts until we have more data on how well the vaccines work. There no reason to believe, though, that “vaccine antibodies” act differently than strong “natural antibodies”.

If you currently have COVID19, you CAN wait up to 90 days for your vaccine. That’s because reinfection is incredibly rare before 90 days. But you CAN get it sooner. Pfizer clinical trials included people who did or did not have COVID-19 previously and some people got the virus during the study. These situations did not present any issues of concern. If you currently have active symptoms of COVID-19, the CDC recommends you wait to get vaccinated until you’ve recovered and met the criteria for ending isolation:

  • At least 10 days have passed since symptom onset AND
  • At least 24 hours have passed since resolution of fever without the use of fever-reducing medications AND
  • Other symptoms have improved.
  • And that’s mainly because we don’t want you infecting other people when you go get your vaccine.

Love, YLE

Data Source:
~10%: https://www.biorxiv.org/content/10.1101/2020.11.15.383323v2.full.pdf ; https://yourlocalepidemiologist.com/how-long-do-antibodies-last/ ; https://yourlocalepidemiologist.com/herd-immunity-and-antibodies/
Ending home isolation: https://www.cdc.gov/coronavirus/2019-ncov/hcp/disposition-in-home-patients.html
How long antibodies last: https://yourlocalepidemiologist.com/covid19-antibodies/