A study shows that in people with mild COVID-19 cases, their antibodies against the coronavirus drop sharply over the first three months after infection.A research team at the University of California, Los Angeles, did an in-depth study of 34 people who had recovered from mild COVID-19 infections. They tested their blood two or three times over three months, Xinhua news agency reported on Tuesday.
The researchers found a rapid drop in antibodies - the immune system proteins that help stop viruses from infecting cells in the body. On average, the antibody levels fell by half every 73 days, according to the study published in The New England Journal of Medicine.
The findings raise concern that humoral immunity against SARS-CoV-2 may not be long-lasting in persons with mild illness, who compose the majority of persons with COVID-19, said the study.
Further studies will be needed to define a quantitative protection threshold and rate of decline of antiviral antibodies beyond 90 days, according to the study.
Meanwhile, a previous study stated that depressed mood or anxiety exhibited in Covid-19 patients may possibly be a sign the virus affects the central nervous system.
The findings, published in the journal The Laryngoscope, revealed that these two psychological symptoms were most closely associated with a loss of smell and taste rather than the more severe indicators of the novel coronavirus such as shortness of breath, cough or fever.
"The unexpected results that the potentially least worrisome symptoms of Covid-19 may be causing the greatest degree of psychological distress could potentially tell us something about the disease," said study researcher Ahmad Sedaghat from the University of Cincinnati in the US.(With IANS inputs)