Coronavirus antibodies may not last long
Since the start of the pandemic, virologists have sought to answer a crucial question: How long-lasting are the antibodies generated by people who survive Covid-19? A small new study suggests the antibodies— protective proteins generated by the body in response to infection—may last as little as two to three months, especially in people who didn’t show any symptoms of the disease. That doesn’t necessarily mean those people can catch the coronavirus a second time, reports The New York Times. Even low levels of neutralizing antibodies can provide effective protection, as can the immune system’s T and B cells. But scientists were hopeful the antibodies would last longer; antibodies for the SARS and MERS coronaviruses last about a year. The new study compared 37 asymptomatic patients with 37 symptomatic ones in the Wanzhou District of China. It found that the antibodies to one viral protein fell below the threshold for detection in 40 percent of the asymptomatic group, but in only 13 percent of those who had experienced symptoms. But a second set of antibodies that can help neutralize the virus was still present—and showed a smaller decline in asymptomatic people than in those who’d had symptoms. Akiko Iwasaki, a viral immunologist at Yale University, says the study highlights the importance of developing a vaccine. “We cannot rely on natural infection to achieve herd immunity.”