The following claim was posted on Instagram, having over 6500 likes at the time of writing:

According to the video, the newly discovered blood group, “Er” is proof that mRNA or messenger ribonucleic acid found in the Covid-19 vaccine is changing the DNA in people, leading to the creation of the Er blood group system.

The claim stems from news in September that scientists at the University of Bristol and the National Health Services Blood and Transplant (NHSBT) had “discovered a rare new blood group system”. The team had investigated three known blood group antigens – molecules on the surface of red blood cells which can trigger an attack by the immune system – which did not fit into any established blood group system.

While the blood group system is a recent discovery, the Er antigens are not a new find, having been discovered more than 40 years ago. According to Stephen Bailey, a spokesperson for the NHSBT: “It was always there. We just didn’t know how different elements were related and that they together formed a system. Er is the 44th blood group system to be discovered. New blood group systems have been regularly discovered for decades.” Bailey added: “One of the antigens that make up the blood group system was discovered more than 40 years ago. The research established that these known antigens, and some newly found antigens are actually part of a blood group system.”

Based on the available evidence then, the claim that the existence of the blood group Er is proof that mRNA vaccines are changing people’s blood types or DNA is false. Antigens from the blood group Er were first discovered 40 years ago.

We had previously debunked a claim that Pfizer-BioNTech’s Covid-19 vaccine will alter human DNA here.