What Offers Better Protection from COVID-19: Previous Infection or Vaccination?

Coronavirus Immunity

Amid the current climate of vaccine hesitancy and pushback against vaccine mandates, the question is continually being raised: what offers superior protection, a vaccine against COVID-19 or natural immunity?

The question is especially pertinent to those who have already contracted and recovered from the disease caused by the SARS-CoV-2 virus.  One such individual, a University of California-Irvine psychiatry professor, Dr. Aaron Kheriaty, felt that because he had already been infected with COVID-19, he should not be required to abide by the university system’s vaccination mandate. Kheriaty took his case all the way to the courts, suing to stop the mandate because “natural” immunity had given him, along with millions of others, better protection than any vaccine could. Last week, a judge dismissed the injunction.

Natural immunity is the type of immunity wherein the body develops its own antibodies after being infected by the COVID-19 virus. While many scientists and doctors corroborate the power of natural immunity in preventing further infections, relying on it alone without vaccinations poses many risks. 

According to a study by the British Society for Immunology, natural infection with SARS-CoV-2 can lead a person to become very unwell first before developing immunity - and immune response can vary from person to person. In addition, its length of protection remains unknown. Meanwhile, vaccination can significantly reduce the chance of developing COVID-19 in the first place, avoiding this state of illness and inducing an immune response in a relatively controlled and safer way. 

The World Health Organization also encourages “herd immunity,” which can be the outcome of a population that has both natural immunity and vaccines. But the WHO expressed support for herd immunity through vaccination, not by allowing disease to spread through any segment of the population, as this would lead to unnecessary cases and deaths. 

“Herd immunity against COVID-19 should be achieved by protecting people through vaccination, not by exposing them to the pathogen that causes the disease,” the WHO stated in December 2020.

As hospitalizations and deaths have risen over the past three months, numerous sources and experts have referred to the surge as a “pandemic of the unvaccinated.”

A large part of the dilemma lays in the fact that this is a novel disease, caused by a novel virus, and scientists just are not yet sure where antibodies to COVID-19 are coming from. While blood tests are regularly used to detect antibodies to other infectious diseases, neither the FDA, nor the Centers for Disease Control and Prevention recommend relying on currently authorized antibody tests to determine whether one is immune to the disease.

“We don’t yet have full understanding of what the presence of antibodies tells us about immunity,” said Kelly Wroblewski, director of infectious diseases at the Association of Public Health Laboratories.

The CDC states that people should get vaccinated regardless of whether they have already had COVID-19, because “research has not yet shown how long you are protected from getting COVID-19 again after you recover from COVID-19.” The agency further points readers to a study showing that unvaccinated people who have survived a COVID-19 infection are two times as likely to get the disease again as compared to individuals who were previously infected and also fully vaccinated afterward. This particular study was conducted among Kentucky residents in spring 2021 among persons previously infected with SARS-CoV-2 in 2020.

In terms of length of protection offered by natural immunity, studies are beginning to trickle in. An analysis published in late September by Dr. Jeffrey Klausner, a clinical professor of population and public health sciences at the University of Southern California, showed that a previous infection generally protects for 10 months or more.

“From the public health perspective, denying jobs and access and travel to people who have recovered from infection doesn’t make sense,” Klausner said.

As the battle continues to rage on, let us know your thoughts on vaccine mandates by filling out BioSpace’s COVID-19 Vaccine Mandates Survey.

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