A major Spanish study has found that antibodies to the coronavirus disappear after just a few weeks in some patients, suggesting that herd immunity to the virus could be unfeasible. The study has found that since the COVID-19 pandemic hit the world, widespread immunity to the virus still has not developed, at least in Spain.

Top epidemiologists in Spain teamed up with the Spanish government to find out what percentage of the Spanish population had already developed antibodies that could protect them from the coronavirus. The study revealed that only 5 percent of those tested had antibodies to the virus, while 14 percent of those who had antibodies in the first round of testing no longer tested positive in the tests that followed weeks later.

The researchers said their findings corroborated previous speculations that immunity to the coronavirus might not last long in people who develop only mild or no symptoms. “Immunity can be incomplete, it can be transitory, it can last for just a short time and then disappear,” said Raquel Yotti, the director of Spain’s Carlos III Health Institute.

Ian Jones, a virology professor at the University of Reading, explained that being asymptomatic suggests a mild infection, which does not really get the immune system going well enough to generate antibodies. “Anyone who tested positive by antibody test should not assume they are protected,” said Jones. “They may be, but it is not clear,” he added.

The researchers said at least 60 percent of the population should develop antibodies to the coronavirus to confirm the presence of herd immunity. However, “we are very far from achieving that number,” according to the study’s lead author, Marina Pollan.

Spain is one of the worst affected countries by COVID-19, with at least 28,000 people dead after catching the virus. Despite that, prevalence estimates remain low and insufficient to provide herd immunity.

In a commentary, Isabella Eckerle and Benjamin Meyer said herd immunity will remain unachievable until most of the population gets exposed to the coronavirus. As of now, most of the population remains unexposed to the virus even in areas with widespread virus circulation.

Coronavirus The new program provides support to the National Urban League, UnidosUS and local nonprofits nationwide to help address rates of infection, joblessness, and the dearth of vital resources needed in Black and Latino U.S. communities disproportionately afflicted by COVID-19. Photo by Tai's Captures on Unsplash