Immunity to the coronavirus disappears within a few weeks, according to the results of a new study, dashing hopes that so-called "herd immunity" will drastically slow the spread of the disease, and throwing the efficacy of an eventual vaccine into doubt as well.
The Guardian reported that a team of researchers at King's College London looked at 90 patients who had developed coronavirus infections. Of those patients, 60 percent had "potent" antibodies while in the midst of the infection. But of those patients, only 17 percent had that same level of potent antibodies just three months later.
Further, some patients had no detectable antibodies just three months after infection.
According to MBL International, antibodies are proteins produced in the body that are a key part of the body's natural immune response. Whenever a pathogen invades the body, the immune system produces these proteins that are intended to destroy the invader. Further, they linger in the body afterward, preventing re-infection; in some cases, for the rest of the patient's life.
However, since antibodies to the coronavirus disappear comparatively quickly, that casts doubt on hopes that so-called "herd immunity" -- that is, when most of a population is immune to a disease and thus provides indirect protection to the portion of the population that is not -- is possible when it comes to COVID-19.
Professor Jonathan Heeney, a virologist at the University of Cambridge, certainly believes this.
"[This study] puts another nail in the coffin of the dangerous concept of herd immunity," Heeney said.
He also noted that some people have taken on a "cavalier" attitude towards the disease.
"I cannot underscore how important it is that the public understands that getting infected by this virus is not a good thing. Some of the public, especially the youth, have become somewhat cavalier about getting infected, thinking that they would contribute to herd immunity," he said.
Further, the study's findings seem to indicate that a single shot of a vaccine will not provide immunity to COVID-19.
In some cases, a single shot of a vaccine provides lifelong immunity to the disease for which the patient is being vaccinated. For example, the MMR (measles, mumps, rubella) vaccine typically given to infants generally provides lifelong immunity to those diseases. Other diseases, such as the seasonal flu, require multiple vaccinations.
Dr. Katie Doores, the study's lead author, says that COVID-19 appears to be falling into the latter category. She suggests that, if a COVID-19 vaccine is developed, patients may have to get it every few months to maintain immunity.