New study shows immunity to COVID-19 higher than antibody tests show

A new study from the Karolinska Institutet and Karolinska University Hospital shows that mild or asymptomatic COVID-19 patients have T-cell immunity against the new coronavirus even if they test negative for antibodies.

The study, which was published at the scientific journal Cell shows that twice as many people have developed T-cell immunity than those detected by antibody tests. The study involved 200 subjects who test positive for SARS-CoV-2, as well as their family members. Health blood donors who gave blood in 2019 and 2020 were used as a control group.

Soo Aleman, a member of the research team, said that it wasn’t just the individuals with verified COVID-19 who showed T-cell immunity, but also many of their exposed asymptomatic family members. Of the healthy control group who donated blood in May 2020 many also showed COVID-19-specific T-cells.

Editor’s Note: The Karolinska study is one of many new studies showing that there are more people who are immune to the coronavirus than we think [see New study found pre-existing SARS-CoV-2 immunity in general population, Study: Some parts of UK are nearing herd immunity]. The difference between this study and others is that the Karolinska research focused on Sweden.

This is important because it confirms that antibodies are not the only sign of immunity against COVID-19. And if healthy blood donors are also showing immunity against the disease, it is probable that a large population of Sweden is now immune to SARS-CoV-2 through their natural encounter with the virus. This can explain why Sweden’s infection and death rates on the decline, and is conclusive proof that lockdowns were useless and vaccines are unnecessary.