LONDON: Patients who have recovered from COVID-19 may lose immunity to it within months of infection due to a steep drop in antibody levels, according to a new study from a British university.
The findings suggest that the virus could re-infect people year-on-year, like common colds. Researchers at King’s College London (KCL) made the discovery after analyzing the immune responses of 90 patients at a London hospital.
They found that while 60 percent of people developed an initially strong antibody response to infection, only 17 percent retained that potency three months later.
Antibody levels fell as much as 23-fold in the period, and in some cases became completely 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, lead author on the study at KCL.
“If your infection is giving you antibody levels that wane in two to three months, the vaccine will potentially do the same thing. People may need boosting and one shot might not be sufficient.”
Prof. Jonathan Heeney, a virologist at the University of Cambridge, said the KCL study confirmed a growing body of evidence that immunity to COVID-19 is short-lived.
“Most importantly, it puts another nail in the coffin of the dangerous concept of herd immunity,” he added.
As more is discovered about the body’s ability, or lack thereof, to fight the virus off repeatedly, so too is more uncovered about the long-term damage it causes.
A study conducted by the British Heart Foundation (BHF), covering 69 countries and 1,261 patients, found that 55 percent of people who had been admitted to hospital had abnormal changes to the way their heart was pumping. Around one in seven of those showed evidence of severe malfunction.
Among patients who had not previously been diagnosed with heart problems, nearly half recorded abnormal heart scans and 23 percent had severe disease.
The researchers cautioned that the study cannot conclude how common heart changes are in people who did not receive scans.
Dr. Sonya Babu-Narayan, associate medical director at the BHF and a consultant cardiologist, said: “Severe COVID-19 illness can result in damage to the heart and circulatory system. We urgently need to understand more about why this is happening so we can provide appropriate care — both short and long term.”
These results follow other studies that indicate that the virus can cause permanent damage to the heart and brain.
Despite the ominous warnings from the KCL and BHF studies, incremental steps are still being made to protect the most vulnerable from the severe short-term effects of COVID-19.
A new antibody treatment that could protect the elderly and those undergoing treatment that weakens the immune system, such as chemotherapy, is being developed by scientists at British-Swedish pharmaceutical giant AstraZeneca.
With human trials set to begin next month, researchers hope that the antibody injection they are developing will ward off infection for up to six months.
But due to the treatment’s high cost, it is unlikely to be used widely. It could, however, be instrumental in lowering the sky-high mortality rates among elderly people who become infected by the virus.