Vaccinating over natural immunity increases the risk of side effects from the vaccines and is completely unnecessary.

https://www.bmj.com/content/374/bmj.n2101

“If natural immunity is strongly protective, as the evidence to date suggests it is, then vaccinating people who have had covid-19 would seem to offer nothing or very little to benefit, logically leaving only harms—both the harms we already know about as well as those still unknown,” says Christine Stabell Benn, vaccinologist and professor in global health at the University of Southern Denmark. The CDC has acknowledged the small but serious risks of heart inflammation and blood clots after vaccination, especially in younger people. The real risk in vaccinating people who have had covid-19 “is of doing more harm than good,” she says.

A large study in the UK and another that surveyed people internationally found that people with a history of SARS-CoV-2 infection experienced greater rates of side effects after vaccination. Among 2000 people who completed an online survey after vaccination, those with a history of covid-19 were 56% more likely to experience a severe side effect that required hospital care.33

Patrick Whelan, of UCLA, says the “sky high” antibodies after vaccination in people who were previously infected may have contributed to these systemic side effects. “Most people who were previously ill with covid-19 have antibodies against the spike protein. If they are subsequently vaccinated, those antibodies and the products of the vaccine can form what are called immune complexes,” he explains, which may get deposited in places like the joints, meninges, and even kidneys, creating symptoms.

Other studies suggest that a two dose regimen may be counterproductive. One found that in people with past infections, the first dose boosted T cells and antibodies but that the second dose seemed to indicate an “exhaustion,” and in some cases even a deletion, of T cells.