The COMMUNITY study, which examines long-term immunity after covid-19, has now followed participants for one year and sees that the vast majority still have high levels of antibodies one year after infection. It has been investigated whether the antibodies bind both to the original virus and to a number of new variants, including Alpha (formerly called B 1.117) and Delta, which are currently spreading in Sweden and Europe. The results suggest continued good protection one year after natural infection.
In the spring of 2020, samples were collected from more than 2,000 employees at Danderyd Hospital, where about 19 percent were shown to have antibodies to SARS-CoV-2. Samples were also collected from more than 100 inpatient covid-19 patients. Now a year has passed and the 12-month follow-up has been completed.
The study took a closer look at a group of study participants who fell ill in the spring of 2020 and who have not yet been vaccinated. In this group, it has been possible to study immunity after natural infection over a period of one year. The results show that over 80 percent of those who had mild symptoms in the spring of 2020 still, a year later, have measurable antibody levels. Corresponding analyzes have also been performed in the group of patients who were hospitalized for covid-19, and all have continued measurable antibody levels one year after the infection.
The researchers have also looked at the ability of antibodies to bind the new virus variants, and found that they also bind the Alpha and Delta variants, which now account for the majority of the spread in Sweden and Europe.