Two new studies give encouraging evidence that having COVID-19 may offer some protection against future infections.

Researchers found that people who made antibodies to the coronavirus were much less likely to test positive again for up to six months and maybe longer.
The results bode well for vaccines, which provoke the immune system to make antibodies — substances that attach to a virus and help it be eliminated.

Researchers found that people with antibodies from natural infections were “at much lower risk … on the order of the same kind of protection you’d get from an effective vaccine,” of getting the virus again, said Dr Ned Sharpless, director of the US National Cancer Institute.
“It’s very, very rare” to get reinfected, he said.
The institute’s study had nothing to do with cancer — many federal researchers have shifted to coronavirus work because of the pandemic.
Both studies used two types of tests.
One is a blood test for antibodies, which can linger for many months after infection.
The other type of test uses nasal or other samples to detect the virus itself or bits of it, suggesting current or recent infection.
Cases of people getting COVID-19 more than once have been confirmed, so “people still need to protect themselves and others by preventing reinfection.”