Confirming Individual Vaccination Efficacy

Question

Approved / mass vaccines are not 100% effective all the time. Trials are stochastic in nature and experiments are designed to avoid bias. Assume for this question that the vaccine has passed regulatory trials / hurdles and is in mass production.

It would be of scientific interest, if not intellectual curiosity, to be able to confirm immunity of a particular vaccinated person. For example, if we wanted to verify a specific vaccinated doctor or other front line worker has conferred immunity to a pathogen. If it advances the question, assume, Dr. Tony Fauci is the physician.

If a person is vaccinated and seeks to confirm immunity (COVID-19):

• can this be performed in-vitro?
• If not, why?
• Is immunity confirmation verifying antibody concentration?

Answer 1

For now the vaccines are in testing, and to some extent some validation of their efficacy will probably be necessary.

Phase 1 trials check whether it is safe to check on efficacy of a drug, phase 2 trials check whether there is any efficacy. So by phase 2 trials some kind of testing needs to be on this (more details here: https://en.wikipedia.org/wiki/Phases_of_clinical_research).

For some vaccines antibody levels (or surrogates) have been the measure of efficacy (see also here: https://www.immune.org.nz/vaccines/efficiency-effectiveness#:~:text=Vaccine%20immunogenicity%20is%20a%20measure,has%20been%20correlated%20with%20protection.).