Probably a vaccinated human with a breakthrough case, you know, exactly like MRSA.
Be careful, methicillin (and generally speaking, antibiotic) resistance are very different, both mechanistically as well as evolutionarily, from vaccine immunity evasion.
First, as a practical matter, small molecules like antibiotics are really difficult to develop, the repertoire is limited, and toxicity is often a big problem. The possible repertoire of antibodies against a given antigen is astronomical.
In the case of antibiotic resistance, you’re dealing with an active colony of bacteria continually reproducing within one host. In vaccine immunity, reproduction is nil or extremely limited within the host (simplifying white lie), and it is mostly at the host-population level that immune evasion evolves over time, so the population dynamics are totally different.
Edit: I recommend Lange’s Medical Microbiology and Janeway’s Immunobiology for those who are interested enough in learning more.
Not with these vaccines. It's VAED
In fact, VAED typically occurs more often in inactivated vaccines, while in comparison, newer mRNA vaccines offer a promising way to reduce the likelihood of VAED.
To the best of my knowledge, though it cannot be ruled out as a possibility, there are no confirmed reports of VAED in humans infected with SARS-CoV-2. You're really splitting hairs and assigning excessive importance on minor details.
https://link.springer.com/article/10.1007/s40259-021-00495-6
https://mvec.mcri.edu.au/references/vaccine-associated-enhan...
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7901381/
https://pubmed.ncbi.nlm.nih.gov/34384810/
https://www.chop.edu/centers-programs/vaccine-education-cent...
- The first 3 links have nothing to do with RNA vaccines
- The fourth link says "the ability of SARS-CoV-2 antibodies to mediate infection enhancement in vivo has never been formally demonstrated", and "the results obtained so far have been rather reassuring", which is in agreement with what I said and in direct contradiction with your point.
- The fifth link doesn't suggest in any way that VAED is a concern with mRNA vaccines. In fact it says: "Any vaccine that has been found to cause ADE has stopped being used or, more recently as described below for dengue vaccine, been recommended only for those who will not be affected by ADE. Evidence of ADE has not emerged for COVID-19 vaccines even though concerns have been raised."
The more likely theory is someone immunocompromised who stayed sick for a very long time.
This is one reason why vaccine distribution inequity may come back to bite us.
I'm more inclined to believe the experts in this instance.
https://www.ucdavis.edu/health/covid-19/news/viral-loads-sim...
It makes zero sense for an immunocomprised person to apply selective pressure to the virus that results in several mutations that perfectly evade the vaccines mechanism of action.
People with a compromised immune system are a good setting for evolving new variante of coronavirus. They stay sick for a long time (meaning more viral replication and more opportunities for mutation) and they apply a weak immune response which while not sufficient to wipe out the disease, provides selective pressure that rewards immune evasion.
There's a common antivaxxer myth that vaccines promote the creation of new variants and that we would be better off without vaccination. I think it's very important to emphasize that is not the case.
> People with a compromised immune system are a good setting for evolving new variante of coronavirus
If it turns out to be the case, should we have HIV / Cancer Patient Passports? After all, these people can be a general danger to public health as they can demonstrably incubate new dangerous strains of diseases, like Omicron.
The important thing to do is get everyone vaccinated, including in Africa where there is a tremendous shortage of vaccines. The more the virus spreads, the more chances it has to mutate into new variants. Also, when everyone is vaccinated, the elderly and immunocompromised are less likely to be exposed to the disease; vaccination should be seen first as a public-health policy, not as a means for individual protection. Not to mention that, even though the vaccination is less effective individually for the immunocompromised, they are one of the groups that are at most risk from covid and therefore most benefit from being vaccinated.
> People with a compromised immune system are a good setting for evolving new variants of coronavirus
> They stay sick for a long time (meaning more viral replication and more opportunities for mutation) and they apply a weak immune response which while not sufficient to wipe out the disease, provides selective pressure that rewards immune evasion.
If what you say is true about immunocompromised people I fail to see a public health argument against their quarantine and certification via passports. We already restrict a much larger and healthier subpopulation (the unvaccinated) so restricting this smaller and disproportionately more dangerous one does seem quite obvious to me, based on public health. And as you say, these people are most likely already hospitalized so quarantine procedures should be fairly easy to implement and follow.