Rutgers study: Stronger, longer COVID infection produces better antibodies
Findings in the Rutgers Corona Cohort study, which began in the earliest days of the COVID-19 pandemic in March 2020, were published in the Aug. 13 issue of the Journal of Infectious Diseases and suggest that people who had severe or long-lasting cases of the coronavirus have higher levels of antibodies needed to fight future infections.
In the study, hundreds have been and continue to be tested regularly for the SARS-CoV-2 virus and its antibodies. Researchers have been analyzing who gets infected and who doesn't, if they have symptoms and what kind, how long those symptoms last, and how the antibodies respond.
Notably, this group was enrolled in the study prior to potential infection.
Among the cohort's 831 participants connected to the Rutgers community, 548 of which identify as healthcare workers, 93 eventually tested positive for the virus in the study's initial phase, which encompassed a six-month follow-up period running through the end of 2020.
The positive test rate equated to 11% overall, but Emily Barrett, Rutgers School of Public Health associate professor of biostatistics and epidemiology, said the healthcare worker percentage was much higher, and the study additionally found their symptoms were more likely to be severe.
Of those, about one-third reported symptoms lasting more than a month according to Barrett, and 10% said they still had symptoms after four months.
Stronger and longer infection, however, tended to indicate a better activation of a person's immune system.
"We did observe that most of the participants who became infected with the virus developed antibodies, which is good news. The strongest predictor of your antibody levels was how severe your symptoms were and how long they lasted," Barrett said. "We did see a handful of people infected who didn't really develop measurable levels of antibodies, and those tended to be people who had asymptomatic infections. So we wouldn't have even known that they had the virus had we not been doing this routine testing."
The numbers back up Barrett's assessment: 96% of participants with severe symptoms had sustained immunoglobulin G antibodies up to six months after initial infection, compared to 79% of asymptomatic carriers.
Given all that information, with asymptomatic and vaccinated people both thought to be contributing at least in part to the spread of the Delta variant, Barrett believes the focus should still be on getting shots into the unvaccinated, rather than the boosters greenlit by U.S. health officials last week.
"Frankly, I'm much more concerned about ensuring that as many people in New Jersey, in the U.S., and worldwide get their first and second doses, and that includes extending our vaccination efforts to children," she said, adding that despite pandemic fatigue, mitigation tactics like mask-wearing should still be observed.
"I think all of the things that we've been taught over the past year, like the basics, are still very relevant today no matter what we're learning, so that is absolutely my strongest recommendation."