Vaccines typically give rise to a stronger antibody response than infection, which might make them better at fending off the virus in the short term. Infection triggers a response that evolves over time, possibly making it more robust in the long term. A combination of both types appears to be stronger than either alone. But the jury is out on whether one form is stronger than the other, and whether their relative strength even matters for vaccine policy…

One thing is clear: Vaccination is a far safer, more reliable strategy for acquiring immunity, given the risks of serious illness or death from infection. But viewpoints splinter about whether people who have had Covid-19 before need a full course of vaccination, and whether documented prior infection should count as proof of immunity—as is the case in some other countries, including much of Europe…

Several peer-reviewed studies conducted in the early part of the pandemic, before widespread vaccination, found that people infected during the first waves were around 80% less likely to test positive during the next surge. Those studies spanned healthcare workers in the U.K., the Danish population and patients at the Cleveland Clinic, a large health system with facilities mostly in Ohio and Florida.