As of 3 days ago there is:
https://science.sciencemag.org/content/early/2020/05/19/scie...
I think this is scientist talk for meaning "likely" but "not exhaustively proven" yet. The article explains the situation very well and I suggest a thorough read. It would be very upending if a virus such as this one did not confer immunity.
edit: from the referenced article:
> To date, no human reinfections with SARS-CoV-2 have been confirmed.
That's the thing about "immunity passport", it implies here you have someone you can expose to the virus all day long. I suspect no one can survive unlimited expose to whatever deadly disease without getting sick.
I mean, as I understand it, for most diseases, the purpose of vaccines is to get the (over-used) "herd immunity", meaning people are immune enough on average to stop the spread of the disease. Situation were a substantial portion of people refuse vaccines (thanx, antivaxer) can result in outbreaks where vaccinated people also get sick.
You mean dose?
The current vaccine research is measuring antibody titres (how much) is being generated by an inoculated individual in reference to a recovered patient. The next step is to determine if those antibodies are actually sufficient as they are different.
My googling also turns up herpes, Epstein-Barr, measles(!), HPV, Hep-B [1]...
It looks like there are many diseases which can find a host reservoir in our body to hide out for a while.
The crux of this is that immunity doesn't last forever but does last for awhile. In measles it looks like 15 years after your two standard MMR vaccines you get from a kid. We have to recognize too that vaccines aren't perfect. Your immune system might not make as strong of an antibody response as another person. You may lose immunity sooner than others. Etc. But the whole premise of the vaccine is that you can get immunity. And if we look at this study, this worked out for most people. Not many people got measles, and of those that did only 9% were vaccinated, which shows that there is a substantial bias for those that weren't vaccinated.
So when I'm saying that people get get immunity I don't mean forever and to every strain, but that they generally get some protection. In fact, this is an essential component to vaccine theory. If you gain __NO__ immunity (for any period of time) from covid, then a vaccine isn't going to do anything because you can't build an immunity. If you get immunity for a year (like with the flu), I think that's a pretty acceptable risk for many and shows that we could build substantial herd immunity just with the younger populations (like with the flu, which the vaccine there isn't even that great, but better than nothing).
And as another note on Shingles, I don't know about you, but chickenpox parties (because it is A LOT worse when you're older) were a thing when I was a kid (I'm not even 30!) and less than 1% of people get shingles. The main factors are being old, immunocompromised, and getting chickenpox before you're 18 months old. Saying you can get reinfected and will get reinfected are different statements with different risk values.
With COVID-19, clearly people get well.
This isn't to say it will protect you forever, and isn't to say there can't be variants that can infect you. But still...
A more fair summary is that they tested on monkeys and the results looks good, in their words:
""" We developed a rhesus macaque model of SARS-CoV-2 infection that recapitulates many aspects of human SARS-CoV-2 infection, including high levels of viral replication in the upper and lower respiratory tract (Fig. 1) and clear pathologic evidence of viral pneumonia [...] data suggest the utility of rhesus macaques as a model for SARS-CoV-2 infection for testing vaccines and therapeutics and for studying immunopathogenesis [...] However, neither nonhuman primate model led to respiratory failure or mortality, and thus further research will be required to develop a nonhuman primate model of severe COVID-19 disease.
Given the near-complete protection in all animals following SARS-CoV-2 rechallenge, we were unable to determine immune correlates of protection in this study. [...] Moreover, additional research will be required to define the durability of natural immunity. """
It certainly points to it working, but it's not conclusive.
The only conclusive test will be a challenge test, where you purposely infect people, or waiting a year after a vaccine to check for reinfection rates.