Vaccinating people who have had covid-19: why doesn’t natural immunity count in the US?

“The US CDC estimates that SARS-CoV-2 has infected more than 100 million Americans, and evidence is mounting that natural immunity is at least as protective as vaccination. Yet public health leadership says everyone needs the vaccine…
 
The evidence: ‘Starting from back in November, we’ve had a lot of really important studies that showed us that memory B cells and memory T cells were forming in response to natural infection,’ says Gandhi [an infectious disease specialist at University of California San Francisco]. Studies are also showing, she says, that these memory cells will respond by producing antibodies to the variants at hand.
 
Gandhi included a list of some 20 references on natural immunity to covid in a long Twitter thread supporting the durability of both vaccine and infection induced immunity. ‘I stopped adding papers to it in December because it was getting so long,’ she tells The BMJ.
 
But the studies kept coming. A National Institutes of Health (NIH) funded study from La Jolla Institute for Immunology found ‘durable immune responses’ in 95% of the 200 participants up to eight months after infection. One of the largest studies to date, published in Science in February 2021, found that although antibodies declined over 8 months, memory B cells increased over time, and the half life of memory CD8+ and CD4+ T cells suggests a steady presence.

Real world data have also been supportive. Several studies (in Qatar, England, Israel, and the US) have found infection rates at equally low levels among people who are fully vaccinated and those who have previously had covid-19. Cleveland Clinic surveyed its more than 50,000 employees to compare four groups based on history of SARS-CoV-2 infection and vaccination status. Not one of over 1300 unvaccinated employees who had been previously infected tested positive during the five months of the study. Researchers concluded that that cohort ‘are unlikely to benefit from covid-19 vaccination.’ In Israel, researchers accessed a database of the entire population to compare the efficacy of vaccination with previous infection and found nearly identical numbers. ‘Our results question the need to vaccinate previously infected individuals,’ they concluded’ …
 
Different risk-benefit analysis? … 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.

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.”