More than half of people infected with Omicron are unaware that they have caught the virus. A new study turns the spotlight on the submerged Covid infection and offers a new estimate of those who run into Sars-CoV-2 without realizing it for the most diverse reasons, because they are asymptomatic or because they underestimate symptoms that occur in mild form.
The work published on Jama Network Open it was conducted by researchers from Cedars-Sinai Medical Center in the US. Among those who turned out to have had the infection, «more than one in two», 56%, «did not know they had been infected. Awareness will be the key to enabling us to move beyond this pandemic, ”explained Susan Cheng, director of the Institute for Research on Healthy Aging in the Cardiology Department of the Smidt Heart Institute at Cedars-Sinai and corresponding author of the study.
Previous studies have already estimated that at least 25% – and possibly up to 80% – of people infected with the pandemic coronavirus may not experience symptoms.
Compared to other variants of SARS-CoV-2, the scientists write, Omicron is associated with generally less severe symptoms that may include fatigue, cough, headache, sore throat, or runny nose. “The results of our studies add to the evidence that undiagnosed infections can increase virus transmission,” notes Sandy Y. Joung of Cedars-Sinai and first author of the study. “A low level of awareness of the infection probably contributed to the rapid spread of Omicron.”
I study
As part of research on the effects of Covid and the impact of vaccines, researchers began collecting blood samples from healthcare workers more than two years ago. In the fall of 2021, just before the start of the surge in the Omicron variant, researchers expanded enrollment to include patients, thanks to the study infrastructure and with the support of Sapient Bioanalytics. Among the healthcare professionals and patients who participated in the research, the scientists identified 2,479 people who had provided blood samples just before or after the start of the Omicron wave and identified 210 people who were likely infected with Omicron based on the levels. most recently positive for antibodies against Sars-CoV-2 in the blood.
Next, the researchers invited study participants to provide health status updates through surveys and interviews. Only 44% of those who had recently positive Sars-CoV-2 antibodies were aware that they were infected with the virus. The majority (56%) were unaware of any recent Covid infections. Of the study participants who were unaware, only 10% reported having recently had symptoms, attributed to a common cold or another type of infection. According to the researchers, more studies involving more people from different ethnicities and communities are needed to learn what specific factors are associated with the lack of awareness of the infection. “But we hope that people will read these results” because “the more we understand our risks, the better the protection of public health and of ourselves,” concludes Cheng.
Hope: downward curve, updated vaccines in September
And, speaking of public health protection, updated vaccines will also arrive in Italy in September. «In recent weeks the curve has been falling, but we must keep our attention high and not consider the challenge won. Ema and Aifa will authorize the new vaccines as early as September and we will be able to give more strength to our campaign ». Health Minister Roberto Speranza said this on TG3.