An Exeter-based research firm has developed what it believes is a “world first” breakthrough test to help confirm the existence of long Covid in some patients.

Attomarker said of those tested 60% showed a poor quantity and quality of antibodies in response to the Covid variant encountered, which can be treated via immunotherapies and vaccines.

There was a hyper immune response to the infection for 15% of those tested, which means their bodies produced too many antibodies, which can cause problems in its own way.

The remaining 25% had an unclear response or diagnosis from the test results.