The US National Institutes of Health (NIH) has launched a clinical trial to evaluate an additional, or booster, shot of an authorised or approved Covid-19 vaccine in autoimmune disease patients.

The trial, named COVID‐19 Booster Vaccine in Autoimmune Disease Non‐Responders, will analyse the antibody response in patients who had no response to an original vaccine regimen against SARS-CoV-2.

It also will assess pausing immunosuppressive drugs for autoimmune disease to improve the antibody response to an additional Covid-19 shot.

Funded by the NIH unit National Institute of Allergy and Infectious Diseases (NIAID), the trial is being performed by the NIAID-funded Autoimmunity Centers of Excellence.

Initially, individuals with multiple sclerosis, pemphigus, rheumatoid arthritis, systemic lupus erythematosus or systemic sclerosis will be enrolled.

The immunosuppressive medication usually taken by these patient populations has been related to poor immune responses to vaccines, NIH noted.

A total of nearly 600 subjects aged 18 years or above will be enrolled at 15 to 20 sites across the US.

Before enrolment, subjects must have experienced a negative or suboptimal antibody response to two doses of the Covid-19 vaccine of Moderna or Pfizer-BioNTech, or one dose of the Johnson & Johnson Covid-19 vaccine.

During the trial, all subjects will be given an additional dose of the same Covid-19 vaccine as their original regimen.

Some participants will be randomised to either pause or continue their immunosuppressive therapy for a short duration prior to and following the extra vaccine shot.

The trial’s primary objective is the proportion of subjects with a significantly better antibody response four weeks following the additional dose compared to after their original shots.

Subjects will be followed for 13 months in total and early data is expected in November this year.

NIAID director Anthony Fauci said: “Many people who have an autoimmune disease that requires immunosuppressive therapy have had a poor immune response to the authorised and approved Covid-19 vaccines, placing these individuals at high risk for the disease.

“We are determined to find ways to elicit a protective immune response to the vaccines in this population.”

Earlier this month, NIH launched a Phase II trial to evaluate a third, or booster, dose of an authorised Covid-19 vaccine in kidney transplant recipients who were unresponsive to the first two doses of the Moderna or Pfizer-BioNTech shots.