Major health care systems in eastern Pennsylvania said they will grant yearlong reprieves from their vaccine rules to those who demonstrate natural immunity.

He cited studies from Israel and elsewhere that suggest infection-acquired immunity can be as robust as those from messenger-RNA vaccines in people who never had COVID-19.

Nurses and other constituents are flooding his office with calls and emails saying officials and companies pushing mandates “totally disregarded” those with natural immunity.

Scientists say some people who have been infected might get a similar immune response as that afforded by vaccines, though individual experiences differ based on factors such as genetics, the nuances of their immune systems and their COVID-19 illnesses.

“It’s a fair statement that natural infection can produce substantial immunity, but it’s much more variable than the vaccinations.

“It is very complicated to try and have a public strategy that relies on people drawing blood and saying, ‘My COVID infection from two years ago still shows protection,’” he said.

“Trying to get protected from COVID through natural infection is not protection; it’s getting infected.

New York state does not allow exemptions for previously infected health care workers subject to vaccine mandates.

Many health care workers in New York had until Monday to get their initial shots, meaning thousands of holdouts might be nudged from their jobs in the coming days.

She said the state might bring in the National Guard or declare a state of emergency that allows qualified health care staff from other states and countries to fill gaps at medical centers whose workers are weary from the pandemic.

“It is unfortunate that the governor and his team have chosen to mandate one of the most stringent vaccine mandates in the country with no reasonable alternatives,” said Michael Cherven, president of the State Police Association of Massachusetts.

Johnson said it is “shocking” that the Biden administration is putting forth mandates and others cannot give firm answers on how natural immunity stacks up against vaccination.

“This administration clearly does not want the public to question whether natural immunity is more effective than vaccines,” the senator said.

“As President Biden revealingly declared, the vaccine mandate ‘is not about freedom or personal choice.’ This administration’s decision to disregard the effectiveness of natural immunity and demand vaccination ignores current data and is an assault on all Americans’ civil liberties.”

Spectrum Health in Grand Rapids, Michigan, said the data supported exemptions for the previously infected if they can show positive PCR or antigen tests for the coronavirus and positive antibody tests

The system said workers who have recovered from COVID-19 ought to get vaccinated, however

“There is increasing evidence that natural infection affords protection from COVID-19 reinfection and severe symptoms for a period of time,” the system said

“Some of the evidence that came out recently from an Israeli study, as well as our own observation, is that if you have had a natural infection — we are talking about that this can be verified by a PCR — that it appears that the kind of immunity that you develop is actually either equal or superior to that than someone who might get two doses of an mRNA vaccine such as Pfizer or Moderna,” Dr

He said people should get the vaccine to maximize their protection and should not try to become infected to achieve immunity