Dr. Aaron Kheriaty, a professor of psychiatry at the University of California-Irvine, thought he did not need a covid vaccine because he had suffered from the disease in July 2020.
So in August, he filed a lawsuit to curb the vaccination mandate of the university system, claiming that “natural” immunity had given him and millions of people better protection than any vaccine could offer.
On September 28, a judge dismissed Kheriaty’s request for an injunction against the university for the mandate, which took effect on September 3. Although Kheriaty intends to move forward with the case, legal experts doubt that his lawsuit and others like it filed across the country will be successful.
That said, there is growing evidence that contracting SARS-CoV-2, the virus that causes Covid-19, is generally as effective as vaccination in boosting the immune system and preventing disease.
However, federal officials have been reluctant to acknowledge any equivalence, citing the wide variation in the immune response of covid patients to the infection.
Like many debates during the covid pandemic, the uncertain value of a previous infection has led to legal challenges, marketing offers, and political outbursts; while scientists work quietly and unobtrusively to clarify the data.
For decades, doctors have used blood tests to determine whether people are protected against infectious diseases. Pregnant women are tested for rubella antibodies to make sure their fetuses are not infected with the virus that causes it, which causes devastating birth defects. Hospital workers are screened for antibodies, against measles and chicken pox, to prevent the spread of these diseases.
But immunity to covid seems harder to discern than those infections.
The Food and Drug Administration (FDA) has authorized the use of covid antibody tests, which can cost about $ 70, to detect a past infection. Some tests can distinguish whether the antibodies are from an infection or a vaccine.
But neither the FDA nor the Centers for Disease Control and Prevention (CDC) recommend using the tests to assess whether you are, in fact, immune to COVID. For that, the tests are useless because there is no agreement on the amount, or the types of antibodies, that would indicate protection against the disease.
“We still don’t have a clear understanding of what the presence of antibodies tells us about immunity,” said Kelly Wroblewski, director of infectious diseases for the Association of Public Health Laboratories.
Similarly, experts disagree on how much protection an infection offers.
In the absence of certainty, and as vaccination mandates are imposed throughout the country, legal demands put pressure on the issue.
Individuals who claim that vaccination mandates violate their civil liberties argue that the immunity acquired by infection protects them. In Los Angeles, six police officers have sued the city, claiming they have natural immunity.
In August, law professor Todd Zywicki alleged that George Mason University’s vaccination mandate violated his constitutional rights, given that he has natural immunity. He cited a series of antibody tests and an immunologist’s medical opinion that it was “medically unnecessary” for him to get vaccinated. Zywicki withdrew the lawsuit after the university granted him a medical exemption that, according to the academic institution, is not related to the lawsuit.
Republican lawmakers have joined the crusade. The GOP Doctors Caucus, made up of Republican physicians in Congress, has urged people who distrust vaccination to take an antibody test, contradicting the recommendations of the CDC and FDA.
In Kentucky, the state Senate passed a resolution granting the same immunity status to those who show a positive vaccination test or antibody test.
Hospitals were among the first institutions to impose an obligation to vaccinate their front-line workers, given the danger that they would spread the disease to vulnerable patients. Few have offered immunization waivers to those previously infected. But there are exceptions.
Two Pennsylvania hospital systems allow clinical staff members to defer vaccination for one year after testing positive for COVID. Another, in Michigan, allows employees to choose not to get vaccinated if they have evidence of a previous infection, and a positive antibody test in the previous three months. In these cases, the systems indicated that they wanted to avoid the staff shortage that could lead to the resignation of nurses who refuse to be vaccinated.
For Kheriaty, the question is simple. “The research on natural immunity is already quite final,” he told KHN. “It is better than the immunity granted by vaccines.” But it is clear that the majority of the scientific community does not share such categorical statements.
Dr. Arthur Reingold, an epidemiologist at UC-Berkeley, and Shane Crotty, a virologist at the La Jolla Institute of Immunology in San Diego, testified as expert witnesses in Kheriaty’s lawsuit, stating that the extent of the immunity provided by reinfection, especially against new variants of covid. They noted that vaccination gives a huge immunity boost to people who have been sick before.
However, not everyone who is pushing for the value of passing an infection to be recognized is a vaccine critic or a champion of the anti-vaccine movement.
Dr. Jeffrey Klausner, a clinical professor of population sciences and public health at the University of Southern California, is a co-author of an analysis, published Sept. 30, showing that the infection tends to protect for 10 months or more. “From a public health point of view, denying work and access and travel to people who have recovered from the infection does not make sense,” he said.
In his testimony against Kheriaty’s arguments in favor of “natural” immunity, Crotty cited studies on the massive covid outbreak that struck Manaus, Brazil, earlier this year that included the gamma variant of the virus. One of the studies estimated, based on analyzes of blood donations, that three-quarters of the city’s population were already infected before the arrival of gamma. That suggested that the past infection might not protect against the newer variants. But Klausner and others suspect that the previous infection rate, presented in the study, had been overstated.
A large study conducted in Israel in August, which showed better protection as a result of infection than vaccination, could help change the tendency to accept previous infection, Klausner said. “Everyone is waiting for Fauci to say, ‘Previous infection provides protection,'” he added.
When Dr. Anthony Fauci, the top federal expert on infectious diseases, was asked during an interview on CNN last month if infected people were as protected as those who have been vaccinated, he hesitated. “There could be an argument that they are,” he said. Fauci did not respond to a request from KHN for further comment.
Kristen Nordlund, a spokeswoman for the CDC, said in an email that “current evidence” shows wide variation in antibody responses after COVID infection. “In the coming weeks, we hope to have additional information on the immunity protection of the vaccine compared to natural immunity,” he added.
A “monumental effort” is underway to determine what level of antibody is protective, said Dr. Robert Seder, chief of the cell immunology section at the National Institute of Allergy and Infectious Diseases. Some recent studies have attempted to establish a figure.
Antibody tests will never provide an affirmative or negative answer about protection against COVID, said Dr. George Siber, a consultant to the vaccine industry and a co-author of one of the papers. “But there are people who are not going to get vaccinated. It’s worth trying to predict who is at the lowest risk. “
KHN (Kaiser Health News) is the newsroom of KFF (Kaiser Family Foundation), which produces in-depth journalism on health issues. Along with Policy Analysis and Surveys, KHN is one of KFF’s top three programs. KFF is a nonprofit organization that provides health information to the nation.