Dutch blood bank says 97% of donors have Covid antibodies

Almost all (97%) of blood donors in the Netherlands have antibodies against Covid-19, blood bank Sanquin said on Monday. In most cases, the antibodies formed after vaccination.

The blood bank has been checking its donors' blood for antibodies since early in the coronavirus pandemic. Blood donors span 18 to 75 years, but not all age groups are equally represented.

Sanquin found that a combination vaccination against Coivd-19 plus recovering from a coronavirus infection results in the most antibodies. People over the age of 60 had fewer antibodies than those under 40. And the ages called to get the AstraZeneca or Janssen vaccines had demonstrably fewer antibodies in their systems by December than those who got Pfizer or Moderna.

The blood bank stressed that the amount of Covid-19 antibodies does not necessarily indicate how well a person is protected against Covid-19. "Just as important is how protective those antibodies are and whether an immune memory and cellular defense are built up," Sanquin said. "These elements are not tested in our research into coronavirus antibodies in donors."

Sanquin will do another antibody investigation between February and May 2022. "We expect to find an increase in the amount of antibodies in donors throughout the Netherlands, as a result of the booster shots and due to contamination with the Omicron variant."