However, adults 65 years of age or older who had been previously infected had only 47.1% protection against repeated infection, compared with a protection rate of 80.5% among younger people, according to the ‘study.
The study authors state that the difference is probably explained by natural changes that weaken the immune system as it ages.
“We know that as we age, the robustness of our immune system decreases,” explains C. Buddy Creech, MD, an infectious disease specialist and director of the Vanderbilt Vaccine Research Program in Nashville, Tennessee. “It’s the reason we give older adults who increase shingles and a high-dose flu shot, or flu shot that contains a special immune stimulant called an adjuvant.”
Natural immunity is not enough
The study highlights the importance of face masks, social distancing, and the COVID-19 vaccine, even for those who have already had the coronavirus, especially if they are older. “Natural protection cannot be relied upon, especially among the elderly,” the study authors wrote.
U.S.-authorized coronavirus vaccines offer significantly better protection than natural immunity, Creech says. “If you take 100 individuals who have all had COVID, their immune response could be all over the map,” he says. “It often correlates with several factors, including the severity of your initial illness. But when you look at the immune response [to the vaccines], are much stronger and more consistent “.
In good news, the study found “no evidence” that a person’s immunity would decline in a six-month period of testing positive for the virus.