SAN DIEGO (KGTV) – It is the question that is on the minds of many survivors of COVID-19: how long will I be protected against the virus again?
A new study by a team from the La Jolla Institute for Immunology is offering the clearest answer to date, and the results are being hailed as “good news”.
The researchers tracked a group of COVID-19 survivors for up to eight months after infection and found that about 95 percent had strong levels of tailored immune system cells, specially adapted to fight SARS-Co-V2.
Their findings suggest that the vast majority of COVID-19 survivors have the immune cells needed to fight reinfection for at least eight months and potentially much longer, based on projections from the data collected so far.
“It certainly looks like there will be immune memory for several years and it wouldn’t be surprising that there would be substantial immune memory for ten years,” said study co-author Dr. Shane Crotty, professor at LJI.
The team measured the levels of antibodies, memory B cells and two types of T cells in the blood of 188 COVID-19 patients, many of whom were located in San Diego.
This was the largest study of its kind to measure all four components of immune memory for any virus, Crotty said.
“The results of almost all the metrics we did were better than we expected,” he said.
While other studies have shown a potentially worrying decline in COVID-19 antibodies over time, LJI researchers have shown that other personalized immune cells continued to stand guard in the body, ready to sound the alarm and call for backup should a patient find the virus again.
“Our data suggest that the immune response exists – and remains,” said study co-author Dr. Alessandro Sette, another professor at LJI.
The findings suggest that about 5% of participants produce a weakened immune memory response. Dr. Crotty suspects that a fraction of the five percent is susceptible to a second infection, but said more research is needed to get a more accurate estimate.
The study comes in the wake of another article on UK healthcare professionals, published in December, which found that COVID-19 antibodies offered protection for at least six months, if not longer.
The JLI researchers examined patients infected with the real virus, what is known as a natural infection, but their findings offer an encouraging clue to the vaccines’ staying power.
“If the memory seemed really tense, that would be a red flag for vaccines,” said Crotty. “That would say that there may be something particularly unusual about the peak.”
Spike is the name of the protein similar to the peak of the coronavirus. Vaccines developed by Pfizer and Moderna instruct the body to build a simulated version of the spike protein to train the immune system.
The LJI findings “are good signs for the vaccine, but vaccines are not infection,” said Crotty. He noted that the body responds to vaccines differently than it responds to natural infections. Some vaccines provide longer-lasting protection than a natural infection; with other vaccines, immunity does not last as long.
He said vaccine manufacturers will need to continue studying inoculated patients to really understand how long the vaccine protection will last.
In the meantime, the LJI team plans to continue measuring immune memory in patients with natural infections and to update their results periodically. With each update, researchers will have a more accurate sense of how long protective immunity can last, said Crotty.