Determination of T-cell response in Covid vaccines

[mktsgm]

TL;DR Summary

Are T-cells induced after a covid vaccine? If so, which kind (th1 or th2 or both)? How do they differentiate so?

Presently some 4-5 Covid vaccines are popular worldwide. pfizer, moderna, astrazeneca, sputnik to name a few. Some Chinese and Indian vaccines are also in the selected markets.

It is said that all these vaccines elicit robust antibody responses against the SARS-cov2 virus.

1. My question is if t-cells are also induced after a Covid vaccine?
   1. If so, which vaccine(s) (or type of vaccine) elicit which type of t-cell response?
   2. I am particularly interested in CD4+ th1 and th2 responses (and their balance also). Is there a certain bias towards either th1 or th2 or both are induced?
   3. I am interested in CD8+ t-cell responses also in vaccines.
   4. Also, I'd like to know about the response of T17, Treg, and Follicular t-cells too in vaccines.
   5. If they are induced, I would like to know the role of PRRs and TLRs in their differentiation. Simply what determines this (CD4+ th1/th2 & CD8+ Tc) differentiation in a Covid vaccine?
   6. Do we have any data if such tests were conducted?
2. My other question how a vaccine-induced immune response is different from a real-infection immune response as far as SARS-cov2 is concerned?

Thanks in advance,

 

[Ygggdrasil]

This is an active area of research, and these are all fairly detailed questions which may or may not have been addressed in the scientific literature. As a starting point, I'd suggest you take a look at the following review article published in the journal Cell in February. While the focus is on the immune response after infection with the SARS-CoV-2 virus, it does discuss data from the vaccine trials:

Adaptive immunity to SARS-CoV-2 and COVID-19
Sette and Crotty. Cell 184: 861 (2021)
https://www.sciencedirect.com/science/article/pii/S0092867421000076?via=ihub
(if the article is behind a paywall at Cell, it is freely available here: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7803150/)

Abstract:

The adaptive immune system is important for control of most viral infections. The three fundamental components of the adaptive immune system are B cells (the source of antibodies), CD4+ T cells, and CD8+ T cells. The armamentarium of B cells, CD4+ T cells, and CD8+ T cells has differing roles in different viral infections and in vaccines, and thus it is critical to directly study adaptive immunity to SARS-CoV-2 to understand COVID-19. Knowledge is now available on relationships between antigen-specific immune responses and SARS-CoV-2 infection. Although more studies are needed, a picture has begun to emerge that reveals that CD4+ T cells, CD8+ T cells, and neutralizing antibodies all contribute to control of SARS-CoV-2 in both non-hospitalized and hospitalized cases of COVID-19. The specific functions and kinetics of these adaptive immune responses are discussed, as well as their interplay with innate immunity and implications for COVID-19 vaccines and immune memory against re-infection.