A disturbing new study reveals that people who are infected with COVID-19 could lose their immunity to the novel coronavirus within months. Researchers at King’s College London analyzed the blood of infected patients and healthcare workers and found that the levels of protective antibodies peaked about three weeks after the first symptoms appeared. However, those antibodies were found in only 17% of the patients three months later.

According to The Daily Caller, in some patients, the antibodies were virtually undetectable.

“People are producing a reasonable antibody response to the virus, but it’s waning over a short period of time and depending on how high your peak is, that determines how long the antibodies are staying around,” said Dr. Katie Doores, one of the lead authors of the study.

The new research suggests that people can get repeatedly infected with the virus, much like they do with the common cold. It also suggests limitations for the effectiveness of a potential vaccine, Doores said.

“Infection tends to give you the best-case scenario for an antibody response, so if your infection is giving you antibody levels that wane in two to three months, the vaccine will do potentially the same thing,” she told The Guardian. “People may need boosting and one shot may not be enough.”

The King’s College study is the first large scale project to monitor antibody levels in patents who have tested positive for the virus three months after symptoms emerged. The study did show that people who had more severe cases of COVID-19 produced higher and more lasting levels of antibodies. And experts told The Guardian that, according to study results, while we can’t expect that infection will grant people immunity, we may expect that future infections could be less severe.