The article is informative on whether or not to vaccinate: you should vaccinate, particularly if you've not already had Covid-19. Severity and mortality for vaccinated individuals is far lower than for unvaccinated.

For those who have had Covid-19, the vaccination ... provides little noticeable additional benefit. In discussion of this article on YouTube, John Campbell, a nurse-trainer PhD (retired) suggests that targeting vaccines to those who have not yet had Covid-19 might be supportable, but that recommendation carries the costs of determinng and tracking this status. As an epidemiological practice, ensuring a full course of vaccinations for all might well be the most effective and logistically-viable option.

That isn't the whole picture either, though, which is why I said someone shouldn't use this article to govern their choice about vaccination.

Someone who has already had Delta is susceptible to Omicron infection. Probably not a severe case, but it's a possibility.

More recent data indicates that adding a vaccination on top of a prior infection takes the risk of severe infection way way down.

Omicron is now 99.5% of cases in the USA. Other variants are nearly extinct.

https://covid.cdc.gov/covid-data-tracker/#variant-proportion...