More people have immunity to coronavirus than antibody tests suggest, new research shows.
The study from Sweden found that for every person who tested positive for antibodies — which are usually a strong indicator of whether someone has previously had an infection — two were found to have specific T-cells which identify and destroy infected cells.
According to the research from the Karolinksa Institute in Sweden, even individuals who had mild or asymptomatic cases of COVID-19 had T-cells, despite testing negative for antibodies.
The research is important because it could mean that more people than first thought have immunity to COVID-19. However, it is not yet clear whether this just protects the individual, or if it also stops them from passing on the infection to others.
Prof Danny Altmann at Imperial College London described the study as “robust, impressive and thorough" and said it added to a growing body of evidence that "antibody testing alone underestimates immunity”.
The results of the study are so new that they have not undergone peer review, nor been published in a scientific journal. Nevertheless, they can be seen as good news from a public health perspective as they indicate that public immunity to COVID-19 is likely a lot higher than first thought.