> Four cohorts of adults aged ≥18 years were considered: persons who were 1) unvaccinated with no previous laboratory-confirmed COVID-19 diagnosis, 2) vaccinated (14 days after completion of a primary COVID-19 vaccination series) with no previous COVID-19 diagnosis, 3) unvaccinated with a previous COVID-19 diagnosis, and 4) vaccinated with a previous COVID-19 diagnosis.
Note that "14 days" gap in point 2. Having completed vaccinations but not yet past those 14 days is a sort of dead zone that either ends up grouped in with "unvaccinated" or, I suppose, could be just dropped altogether.
That group really needs to be broken out into its own thing, as that's (one of) the thing(s) the people who are straight against these vaccines are concerned about. They're saying that for those 14 days, you're more prone to infection than someone who is actually unvaccinated, and end up counted in the unvaccinated stats if you are infected.
That said, nothing we know about how vaccines or the immune system works should lead us to believe someone is more susceptible to a disease immediately after being vaccinated.
Although, if we're already talking about "people straight up agains these vaccines", then it's pretty evident they already don't give two shits about the science and it's just some weird sociopolitical agenda or conspiracy theory.
Context here is concerning conferred immunity from natural infection. From the abstract:
During May–November 2021, case and hospitalization rates were highest among persons who were unvaccinated without a previous diagnosis. Before Delta became the predominant variant in June, case rates were higher among persons who survived a previous infection than persons who were vaccinated alone. By early October, persons who survived a previous infection had lower case rates than persons who were vaccinated alone.
Implications:
[V]accination remains the safest strategy for averting future SARS-CoV-2 infections, hospitalizations, long-term sequelae, and death. Primary vaccination, additional doses, and booster doses are recommended for all eligible persons.
The results speak more to the likely epidemiological consequences of widespread exposures due to the Omicron variant than any changes to existing guidelines. Note that the study does not cover the period in which the Omicron variant was pervasive, instead focusing on Delta and earlier variants of the SARS-COV-2 virus.
That said, if the findings hold, where Omicron has been widespread most people will end up with exposure and probable improved immune response. It is still advisable to get vaccinated and boosted, but there's some increased hope that the worst of the COVID-19 global pandemic may finally be passing, if not now then in the near future, after the wave has passed in more parts of the world.
Continued mutations and variants of the SARS-COV-2 virus remain a concern, and so long as the virus is extant in human and animal populations, such mutations are all but inevitable. Their implications are exceedingly difficult to predict.