New research from Beijing, China, discovered that the antibody levels of COVID-19 patients who have recovered are rapidly declining.
Antibody Levels Falling Rapidly
According to Reuters, the levels have started falling just two to three months after the patients, who are both symptomatic and asymptomatic, have recovered from the viral infection, raising the questions on the length of immunity against the novel coronavirus.
The research was published in the journal Nature Medicine on June 18 and done by scientists from the Chongqing Medical University, a branch of the Chinese Center for Disease Control and Prevention.
It highlights the risks of the so-called "immunity passports" that some governments have been proposing.
These "immunity passports" or "risk-free certificates" would allow recovered patients who have antibodies that will work against the virus to go out and join the public, assuming that they couldn't be infected with it again, as noted by the World Health Organization (WHO).
In addition, the team also supports the prolonged public health interventions, including social distancing and isolating people who are at high risk of getting COVID-19, including elderly people.
Testing Symptomatic and Asymptomatic Patients
The team examined 37 asymptomatic patients and 37 symptomatic patients who tested positive for the presence of IgG antibody, one of the main antibodies created after an infection.
After checking their antibody levels, the scientists found that 90% of them have shown sharp declines of IgG levels.
For both the symptomatic and asymptomatic COVID-19 patients, the median was 70%, while 11.7% of the symptomatic patients and 8.3% of the asymptomatic patients have decreased neutralizing serum antibodies over time.
Nevertheless, an expert who wasn't part of the study said that it doesn't negate the possibility that other parts of the immune system could offer protection.
Should We Worry?
"The finding in this paper doesn't mean the sky is falling," virology Professor Jin Dong-yan of the University of Hong Kong said.
The professor also mentioned that some cells of the body familiarize themselves with how to cope with the virus when it was first infected, which would offer us some protection in case the second round of infection happens.
Scientists are still studying whether the same mechanic works with COVID-19, caused by the new coronavirus.
In addition, the professor also said that the number of participants that the scientists had was small.
Further studies might be required before experts can assert whether the new research could affect the questions regarding the immunity we can get after recovering from COVID-19.
Although several countries were able to flatten the curve, the rest of the world is still negatively impacted by the coronavirus pandemic. They are experiencing their first and/or second waves of infection.
With that, the WHO encourages people to remain vigilant.
They have even employed the help of the infamous fictional character Mr. Bean to help spread the word on how to avoid coronavirus infection through the "Mr. Bean's Essential COVID-19 Checklist."