A doctor in Far Rockaway whose virus updates I receive sent out the following yesterday, which seems to say that the antibodies produced by the vaccine are NOT necessarily the same as those produced in response to infection. Similarly, Rabbi Dr. Glatt said in one of his recent Motzei Shabbos programs that he was surprised that several of his medical colleagues tested themselves for antibodies after getting vaccinated and were disappointed that their tests came back negative. He explained that the antibodies tested for by current antibody tests are not necessarily the same as those produced by the vaccine, so he discouraged those who've been vaccinated from doing so. Any additional insights on this topic @biobook or anyone else?
At this time, it is NOT recommended that vaccinated people test for antibodies.
Current data indicates that most vaccinated people will develop a significant degree of immunity by two weeks after their second dose.
However, it is possible that vaccinated people will produce antibodies that differ slightly from those produced by actual infection and therefore will not be detected by current lab tests.
New antibody tests will hopefully be available in the near future that will test for the specific type of antibodies produced after vaccination.
Where do you get Dr. Glatt's videos? I used to find them on 5tjt, but they seem to have stopped.
What I wrote above was based on my understanding of what Dr. Bar-Zev had said in that video, and he's the expert, but I would also say that Dr. Glatt is the expert, so I guess the conclusion is that experts are still debating this. That's actually what the CDC says:
If your body develops an immune response—the goal of vaccination—there is a possibility you may test positive on some antibody tests. Antibody tests indicate you had a previous infection and that you may have some level of protection against the virus. Experts are currently looking at how COVID-19 vaccination may affect antibody testing results.
https://www.cdc.gov/coronavirus/2019-ncov/vaccines/facts.htmlIn addition to possible differences in antibodies, it is also possible that the antibody response is low, but the T cells are high, and maybe the T cells are more important for maintaining immunity after vaccination.
But if you did test for antibodies after taking the vaccine and you did get a positive result - does that prove that you now have antibodies?
You have antibodies, but it's not clear what level of antibodies is enough for immunity, and not clear what the importance of antibodies are relative to T cells for immunity.
https://www.cnbc.com/2021/01/12/covid-vaccine-labcorp-ceo-says-recipients-dont-need-antibody-test-afterward.html