Unfortunately, T-cell tests are not available in Europe, and apparently not reliable in the US. Which confirms the original point: there seems to be little interest in detecting previous infections.

Many people who have been infected with SARS-CoV-2 will probably make antibodies against the virus for most of their lives. So suggest researchers who have identified long-lived antibody-producing cells in the bone marrow of people who have recovered from COVID-191.

The study provides evidence that immunity triggered by SARS-CoV-2 infection will be extraordinarily long-lasting. Adding to the good news, “the implications are that vaccines will have the same durable effect”, says Menno van Zelm, an immunologist at Monash University in Melbourne, Australia.

https://www.bloomberg.com/news/articles/2021-08-27/previous-...

Previous Covid Prevents Delta Infection Better Than Pfizer Shot

https://www.science.org/content/article/having-sars-cov-2-on...

The natural immune protection that develops after a SARS-CoV-2 infection offers considerably more of a shield against the Delta variant of the pandemic coronavirus than two doses of the Pfizer-BioNTech vaccine, according to a large Israeli study that some scientists wish came with a “Don’t try this at home” label.

Which T-cell test(s) are you referencing? What are the rates of false negatives or false positives?

Particularly when natural immunity comes for "free" and apparently works better, at that point insisting on vaccines for everybody is just completely nonsensical.

Rather shift resources to testing to get costs for that down, which is more work, but also doesn't come with the risk of later discovering "Oops, this vaccine that made people filthy rich turned out to have some nasty long-term side-effects!".

Which is also a very real possibility, considering they've been developed and approved in record time with the population at large acting as subjects for the first non-clinical trials.

The prophylactic costs less than the diagnostic. It has negligible risk of harm. It's a determinable and unambiguous event, unlike trying to verify a possible infection and sustained immune response.

The obvious rational policy decision for public health is to mandate the vaccine for everyone.

Those not previously infected gain immunity. Those previously infected ... either get a not-strictly-necessary injection, or far more likely, a useful booster.

And the administration, diagnostic, and monitoring costs are far lower.

Quebec is the only province that will let you get only 1 dose of the vaccine, instead of 2, if you were previously infected. With that 1 dose, that's enough to have access to the vaccine passport.

But there are absolutely no places in Canada that accepts prior infection as being fully vaccinated.

My comment was not intended to be an argument against any testing for pre-infection; I think the rationale for that is pretty solid, but I think that the regulatory establishment needs to be prepared to inform people that they might not be able to prove their previous infection and in that case they should get vaccinated.

This was back before tests were widely available. I have genuinely had it twice myself, but people largely have though for the past two years that if they were sick it was COVID.

How soon after you were ill? Aren't the antibodies nigh undetectable XX weeks after you recover?

Does the US now have a digital verifiable certificate system for tested or previously infected as well as vaccinated or is it still a piece of paper?

Without this you have to just vaccinate everyone because there is no other way to manage it.