Repeated corona vaccines provide good protection for people with weakened immune systems

More than 50,000 Norwegians are taking a common type of medicine to suppress their immune system. A new study shows that these patients are no longer at high risk of severe COVID-19.

TNF inhibitors are medications that suppress the immune system and reduce inflammation in the body. These medications may also weaken the effectiveness of coronavirus vaccines. 

– We have been uncertain about how corona vaccines work over time for patients who use medications to suppress the immune system. We have also wondered how long these people should be considered to be in the risk group for severe corona disease. This has implications for whether they should get vaccinated every year, says doctor Hilde Ørbo.

She is a researcher at the REMEDY research center at Diakonhjemmet Hospital. She has contributed to a new study on the topic.

Doctor and researcher at Diakonhjemmet, Hilde Ørbo, has investigated how patients with impaired immune systems receive better protection through vaccination. (Photo: Nicolas Tourrenc / Diakonhjemmet Hospital)

Medicine suppresses the immune system

The patients included in this study have autoimmune diseases of the joints and intestines. 

In autoimmune diseases, such as rheumatoid arthritis, the joints are attacked by the body's own immune system. In diseases of the intestine, such as Crohn's disease or ulcerative colitis, the intestines are attacked by the immune system.

The patients in the study have such diseases and use TNF inhibitors to suppress the immune system.

More vaccine doses give better effect

The study shows that these patients have strengthened their immune systems after four doses of the vaccine. When the patient has also had a corona infection, protection against new infections is even better.

This is good news for these patients who have had to take more vaccines than healthy people to achieve good protection.

– The immune system appears to adapt to new variants of the virus both after updated vaccines and infection, says Ørbo.

Patients who have had corona in the last six months have not benefited from a new dose of vaccine.

However, those who had not had infection received additional benefits from a new dose of vaccine.

May change vaccine recommendations

The study may change vaccine advice for patients treated with TNF inhibitors, who are still recommended to get an annual vaccine.

– Patients without a higher risk of severe corona disease can probably follow the same advice as the general population, after four or five vaccine doses. This applies to those who are younger than 65 years of age and without other diseases that increase the risk of severe corona disease, says Ørbo.

Important collaboration for more knowledge about vaccination

The study is part of Nor-vaC , a collaboration between several hospitals and the Norwegian Institute of Public Health. The collaborating hospitals are Diakonhjemmet Hospital, Akershus University Hospital and Oslo University Hospital.

The project provides insight into how patients with compromised immune systems receive better protection through vaccination.

“We continue to follow this group of patients to find out how they can get the best possible protection from vaccines,” says Guro Løvik Goll. She is a consultant at Diakonhjemmet Hospital and is leading the Nor-vaC study.

Reference:

Hilde S. Ørbo et al.: Humoral and cellular responses to a fifth bivalent SARS-CoV-2 vaccine dose in patients with immune-mediated inflammatory diseases on tumor necrosis factor inhibitors: a prospective cohort study . The Lancet Regional Health – Europe, 2025.