British study finds in adults 3% to 10% already have a few antibodies against Covid-19 due to past “common cold” infections. Children have an even higher %
In a group of 50 blood samples from pregnant people from May 2018, the team found that 10% had cross-reacting antibodies. In a separate cohort of 101 samples from May 2019, three had these antibodies.
In a further experiment, the team analyzed 13 additional samples from adults who had recently had an infection with a common cold coronavirus. Of these, only 1 sample had cross-reacting antibodies.
Overall, the authors report, 16 of 302 samples, or 5.29%, had SARS-CoV-2 cross-reacting antibodies. The median age of the donors was 51 years. ...snip... To look for a link between age and SARS-CoV-2 cross-reacting antibodies, the team analyzed 48 blood samples from children and adolescents aged 1–16 years. All of the samples stemmed from before the pandemic.
Here, they found that 21 of the samples had cross-reacting antibodies, while in a separate cohort of samples from people aged 17–25 years, these were only present in one sample.
“Our results show that children are much more likely to have these cross-reactive antibodies than adults.
