March 10, 2023 – A latest study from Switzerland finds that healthcare employees infected with the Omicron variant of COVID-19 were far less more likely to develop significant long-COVID symptoms than people infected with the unique SARS-CoV-2 virus.
The resultsPeer-reviewed studies to be presented on the European Congress of Clinical Microbiology and Infectious Diseases in April showed that folks infected with the unique “wild-type” virus that was circulating within the early months of the pandemic still had persistent post-COVID symptoms 18 months later. At the identical time, reinfection with Omicron on this group didn't appear to extend their long-COVID risk.
“In a young and healthy population, the risk of long-COVID disease after an omicron infection is very low, regardless of vaccination status,” says Dr. Philipp Kohler of the Cantonal Hospital of St. Gallen and lead investigator of the study in an email.
“These data suggest that the long COVID wave following omicron infection will not be as devastating as many feared.”
The latest findings construct on previous research, including an article Published in The Lancetwhich showed that the chance of long COVID disease was lower with Omicron in comparison with the Delta variant. Another study Published in Nature communication When comparing the identical variants, Omicron was also found to have a lower risk of long-term symptoms three months after a positive test.
In the Swiss study, which has yet to be submitted to a medical journal for publication, Kohler and his colleagues followed 1,201 health care employees from nine national health networks, tracking their vaccination status and comparing symptoms with an uninfected control group.
“Taking this 'background noise' into account is very important because it allows us to separate the effects of Long COVID from other conditions that are common in the general population and cause similar symptoms to Long COVID, such as fatigue,” Kohler said.
Over the subsequent two years, healthcare employees accomplished online questionnaires 3 times to point whether or not they had symptoms of long-term COVID illness and the severity of their fatigue. Eighteen symptoms were recorded, with lack of smell or taste, fatigue and weakness, burnout and exhaustion, and hair loss being essentially the most commonly reported problems.
In the study, those that tested positive for the unique virus had a 67% higher risk of developing long-COVID symptoms when surveyed in March 2021 than the control group of participants who remained uninfected. While symptoms subsided over time, they were still present 18 months later.
Meanwhile, the chance of developing long COVID didn't look like greater amongst employees who were infected with Omicron for the primary time than amongst those that had never been infected with COVID-19, the researchers found. Participants' fatigue rates were also comparable between the infected and uninfected groups.
“We can only speculate why this was the case,” said Dr. Carol Strahm, an infectious disease specialist and one in all the researchers involved within the study, in an announcement. He added that it may very well be because Omicron is less more likely to cause severe disease than the unique virus, in addition to immunity acquired through previous exposure, including asymptomatic infections that never led to the event of antibodies.
However, Kohler noted that the sample size was not very large and that the group studied doesn't reflect the broader population. Older people, individuals with other health problems and the unvaccinated can have different results, he said.
Linda Geng, co-director of the Post-Acute COVID-19 Syndrome Center at Stanford University, who was not involved within the Swiss study, said that while there may be research suggesting that the long-COVID risk could also be lower after infections with Omicron in comparison with previous variants, she continues to be treating many latest patients.
“In our Long COVID clinic, we are still seeing many Long COVID cases that have developed after more recent infections,” Geng, who can also be a clinical assistant professor of medication within the university’s division of primary care and population health, said in an email.
“We also don't know how the virus will evolve in the future and what impact it will have on the risk of long COVID. The only guarantee against long COVID is not getting infected with COVID.”
The Swiss team plans to proceed monitoring participants to find out whether those infected with the unique strain proceed to report symptoms almost three years later.