When the coronavirus first emerged and revealed its deadly nature, one assumption provided comfort, even without a possible vaccine or clinically tested treatment in sight: If we get infected and recover, at least we know we’re safe!
That assumption was quickly shattered after people in Italy, Hong Kong, and the United States became reinfected with SARS-CoV-2. Their infections sparked panic about the future of the pandemic, the efficiency of potential vaccines, and the true dangers of the coronavirus.
Vaccines can only work if they induce long-lasting antibody reactions that work day after day, year after year, to defeat any signs of COVID-19. But studies on coronavirus antibodies haven’t been entirely encouraging. A Chinese study published in June, for example, reported that levels of an antibody correlated to COVID-19 fell sharply only two to three months after infection.
A similar study reported that asymptomatic individuals reacted less to infection, with 40% of asymptomatic volunteers showing undetectable levels of protective antibodies in two to three months after infection.
These results left experts concerned that only the worst and near-deadly cases of COVID-19 cases can produce a sufficient, long-lasting antibody immune response. If so, infected children and young adults who escape the worst symptoms would be more vulnerable to reinfection.
However, researchers in Iceland recently published a study in the New England Journal of Medicine that offers a glimpse of hope that COVID-19 immunity may not be as elusive as we feared.
Studying Antibodies in Serum Samples in Iceland
A team of researchers in Iceland examined serum samples from 30,576 individuals using six distinct types of antibody testing. Of the 1,797 people who had recovered from COVID-19, 91.1% of their serum samples exhibited detectable levels of antibodies.
Even more significantly, those antibody levels hadn’t declined in the four months since their diagnosis. Older individuals and those who presented the worst symptoms while infected showed a higher immune response in their serum samples.
Overall, the broad immune response observed in this study confirms that reinfections may continue to be rare, at least shortly after the first illness. Scientists still need more time to determine if antibody behavior will remain consistent over a longer period of time. It hasn’t even been one year since the pandemic began, so at this point, there’s still too much that experts don’t know or can’t confirm.
However, even with so many unknowns, the study out of Iceland offers promising evidence that the human body can indeed develop protection against the coronavirus after infection.