New York, Jan 6 (IANS): Covid infection, even if mild, can trigger an immune response that lasts longer than the initial infection and recovery, according to a new study.
The study by scientists at the Cedars-Sinai Medical Center, Los Angeles, showed that the presence of elevated autoantibodies after mild or asymptomatic infection, as well as their persistence over time, Jerusalem Post reported.
The team included 177 people with confirmed evidence of a previous Covid-19 infection.
The findings, published in the Journal of Translational Medicine, revealed that people with a prior infection of SARS-CoV-2, the virus that causes Covid-19, have a wide variety of autoantibodies up to six months after they have fully recovered.
Some of these autoantibodies can attack the body's own organs and tissues over time, the report said.
"These findings help to explain what makes Covid-19 an especially unique disease," Justyna Fert-Bober, PhD, co-senior author of the study was quoted as saying.
"These patterns of immune dysregulation could be underlying the different types of persistent symptoms we see in people who go on to develop the condition now referred to as long Covid-19," Fert-Bober added.
The researchers noted that they intend to expand the study to look for the types of autoantibodies that may be persistent in people with long-haul Covid-19 symptoms.
It remains unclear whether autoantibodies are similarly made in people with breakthrough infections because the study was conducted before vaccines were rolled out, the report said.
A study led by researchers at Peking University in China showed that about four in 10 Covid cases are asymptomatic, making them potential sources of increased transmission of the infectious disease.
The study also showed that the percentage of asymptomatic infections was higher among groups younger than 39 years than in other age groups, possibly because the young adults were more likely to show only mild or moderate clinical symptoms. This indicated that young adults who often presented mild or no symptoms were a potential source of transmission in the community.
"Screening for asymptomatic infection is required, especially for countries and regions that have successfully controlled SARS-CoV-2. Asymptomatic infections should be under management similar to that for confirmed infections, including isolating and contact tracing," said Qiuyue Ma, Department of Epidemiology and Biostatistics, from the University.
The findings on long Covid were also recently raised by US top infectious disease expert Anthony Fauci,
"Long Covid can happen no matter what virus variant occurs. There's no evidence that there's any difference between Delta or Beta or now Omicron," Fauci was quoted as saying in an interview with Spectrum News.
Long-term symptoms usually include shortness of breath, fatigue, difficulty concentrating, insomnia and brain fog.