Evidence is growing that contracting SARS-CoV-2, the virus that causes COVID-19, is generally as effective as vaccination at stimulating your immune system to prevent the disease.

A large August study from Israel, which showed better protection from infection than from vaccination, may help turn the tide toward acceptance of prior infection, said Dr.

The Food and Drug Administration has authorized the use of COVID-19 antibody tests, which can cost about $70, to detect a past infection.

In the absence of certainty and as vaccination mandates are levied across the country, some are filing suit, arguing that infection-acquired immunity protects them.

In August, law professor Todd Zywicki alleged that George Mason University’s vaccine mandate violated his constitutional rights given he has natural immunity.

In Kentucky, the state Senate passed a resolution granting equal immunity status to those who show proof of vaccination or a positive antibody test.

Two Pennsylvania hospital systems allow clinical staff members to defer vaccination for a year after testing positive for COVID-19.

Another, in Michigan, allows employees to opt out of vaccination if they present evidence of previous infection and a positive antibody test in the previous three months.

So, in August, he sued to stop the university system’s vaccination mandate, saying “natural” immunity had given him and millions of others better protection than any vaccine could3

In his testimony against Kheriaty’s case for natural immunity to COVID-19, Crotty cited studies of the massive COVID-19 outbreak that swept through Manaus, Brazil, early this year that involved the gamma variant of the virus.

CDC spokesperson Kristen Nordlund said in an email that “current evidence” shows wide variation in antibody responses after COVID-19 infection.

“We hope to have some additional information on the protectiveness of vaccine immunity compared to natural immunity in the coming weeks.”.

Antibody tests will never provide a yes-or-no answer on COVID-19 protection, said Dr.