Research shows COVID-19 immunity different than flu immunity, antibodies drop ‘rapidly’ after recovery

Researchers in Montreal and Toronto are studying the body’s immunity response to COVID-19, and early findings show that immunity to the novel coronavirus is less protective than that to influenza — the common flu.

Tania Watts, a PhD with the department of immunology at the University of Toronto, says researchers took blood cells from 13 people who had recovered from COVID-19 within four to 12 weeks since the patients’ full recovery, then stimulated their blood cells with parts of the virus to see if their immune cells would recognize the virus an create a response.

“We compared these responses to what we see with the common influenza virus, a virus to which most adults are immune and are exposed to often,” Watts said.

“All the SARS-CoV-2 (COVID-19) recovered patients had immune memory responses to both SARS-CoV-2 and to the influenza virus, but with significant differences in how they responded.”

Study co-lead Dr. Mario Ostrowski said the response in individuals whose blood cells were stimulated with COVID-19 showed increased inflammation and showed a response that shows less protection from infection than when people’s blood was stimulated with the influenza virus.

Ostrowski said the study is looking to find out whether the immune cells in the blood of someone who has recovered from COVID-19 will react similarly or differently to the COVID-19 vaccine.

Researchers at Université de Montréal say their early research findings on COVID-19 immunity shows that antibody levels in the blood of patients drop rapidly during the weeks after their immune systems clears the virus and symptoms have subsided.

The research team in Montreal says their research will be looking into whether health officials will be able to predict which COVID-19 patients will experience the disease in a severe way, whether recovered patients can develop long-term protective immunity, if antibody tests could indicate which patients are at higher risk of re-infection and whether re-exposure to the virus boosts immunity.