By NewsDesk  @infectiousdiseasenews

The Swedish Public Health Agency conducts recurring  seroepidemiological examinations in which the presence of antibodies for detection of the covid-19 review is analyzed. The surveys have been conducted on a number of occasions during 2020 and 2021 and include periodic collections of surplus blood samples from outpatient care and samples from blood donors.

Image by fernando zhiminaicela from Pixabay

During the last week of May and the first week of June, the presence of antibodies to SARS-CoV-2 was examined in excess blood samples collected from outpatient laboratories in eight regions. The blood samples came from children, adolescents and adults as well as older adults aged 0-95 years. The analyzes show that 85 percent in the group 65-95 years had antibodies, while the level was 52 percent in the group 20-64 years and 28 percent in the group 0-19 years. On average, the entire group had 52 percent antibodies.

– As expected, there is a high level of antibodies in the older age groups where vaccinations have come a long way. Since we know that only a small proportion of the population in this age group has had covid-19, this shows that the absolute majority of everyone who has been vaccinated develops detectable antibodies, says Mia Brytting, unit manager at the Swedish Public Health Agency.

Also in the blood donor group, 52 percent had antibodies during the same study period. This is an increase compared to the surveys conducted in early March 2021, where one in four blood donors had antibodies. The increase is linked to the fact that many have since received at least one dose of vaccine.

Young people

In the case of children and adolescents aged 0-19 years, the survey of antibodies from blood samples in outpatient care, the last week of May and the first week of June, shows that 28 percent had antibodies. The highest incidence was in the group 16-19 years, where 37 percent had antibodies. However, it was lower in the group 0-10 years where 22 percent had antibodies and in the group 11-15 years where 34 percent had antibodies. The proportion vaccinated among the young was during the corresponding period, as expected, very low.

In another study, 30 percent in the 11-19 age group had antibodies. The study was conducted in the last week of April and the first week in May. No one in the study group was vaccinated at the time of the study.

– Although our surveys show that just over 30 percent of young people have antibodies, this also shows that two thirds probably have no protection against covid-19. It is therefore important that young people are aware that covid-19 can still be spread in this group, says Mia Brytting

The antibody analyzes were performed in collaboration with SciLifeLab / KTH and with Xerum AB.

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