Recent research has found that individuals who have recovered from COVID-19 have exhibited lasting immunity for up to eight months.
To better understand immune memory of SARS-CoV-2, researchers led by Drs. Daniela Weiskopf, Alessandro Sette, and Shane Crotty from the La Jolla Institute for Immunology analyzed immune cells and antibodies from almost 200 people who had been exposed to SARS-CoV-2 and recovered.
Antibodies against the spike protein of SARS-CoV-2, which the virus uses to get inside cells, were found in 98% of participants one month after symptom onset. Promisingly, their levels remained fairly stable over time, declining only modestly at 6 to 8 months after infection.
The researchers will continue to analyze samples from COVID-19 patients in the coming months and hope to track their responses 12 to 18 months after the onset of symptoms.
In the study, researchers found the number of antibodies ranged widely between individuals. In fact, the researchers saw a 100-fold range in the magnitude of immune memory. People with a weak immune memory may be vulnerable to a case of recurrent COVID-19 in the future, or they may be more likely to infect others.
“There are some people that are way down at the bottom of how much immune memory they have, and maybe those people are a lot more susceptible to reinfection,” says Crotty.
A recent article by WebMD, reported that recovery from severe COVID illness could result in stronger long-term immunity afterwards — compared to those who have recovered from mild illness.
The fact that immune memory against SARS-CoV-2 is possible is also a good sign for vaccine developers.
“It is possible that immune memory will be similarly long lasting similar following vaccination, but we will have to wait until the data come in to be able to tell for sure,” says Weiskopf.” The vaccine studies are at the initial stages, and so far have been associated with strong protection. We are hopeful that a similar pattern of responses lasting over time will also emerge for the vaccine-induced responses.”