Mask mandates are being lifted across the US. Coronavirus cases and hospitalizations are dropping. People are getting vaccinated.
All these promising signs suggest the summer of 2021 could be very different from a year ago.
Half of the adult population is fully vaccinated, according to data published Wednesday by the US Centers for Disease Control and Prevention. In the past week, the US averaged about 28,000 daily new cases each day, a 19% drop compared to the previous week, according to the CDC.
However, a new study underscored the importance of vaccinating more people as it detailed how some of those who had Covid-19 can suffer from symptoms months later.
Nearly three-quarters of patients with moderate-to-severe Covid-19 had at least one long-term symptom, according to the analysis published Wednesday in JAMA Network Open.
Researchers from Stanford University conducted a review of 45 studies that followed 9,751 patients in the months after a Covid-19 infection. They found 73% of the patients had at least one symptom 60 days after diagnosis, symptom onset or hospital admission. That finding was consistent even in studies that followed patients up to six months.
The researchers also found across the studies that 40% of participants experienced fatigue, 36% had shortness of breath and another 25% reported an inability to concentrate, often referred to as brain fog.
“We had no data on individuals who got Covid-19 and simply went about their day, so we don’t want to cause a lot of alarm with the value of 73% of people experiencing long-term outcomes,” Tahmina Nasserie, a Ph.D. candidate in epidemiology and population health at Stanford University and the lead author of the study, told CNN. “We want people to understand that these are mainly hospitalized so we can only generalize our findings for that particular population.”
Another study, by researchers at the national clinical laboratory LabCorp, found that as many as nine in 10 people infected with Covid-19 develop immunity against the virus that is “sustained with little decay through ten months.” Within three weeks, 90% of people in the study developed antibodies to Covid-19, the study found.