This study found that about 4 in 5 people with a weakened immune system had antibodies after having 3 or more vaccines. People who had more doses of vaccine were more likely to have antibodies. The researchers recommended that people have vaccines and booster doses to increase their likelihood of developing antibodies to Covid-19.

 

Background

People who have a weakened immune system are more likely to catch covid-19 and more likely to need hospital treatment or die from covid-19. Antibodies protect people by fighting the infection and preventing serious illness. Vaccines trigger the immune system to make antibodies. If your immune system is weak, you may not respond well to the vaccine and produce enough antibodies.

This study aimed to find out how well vaccines protect people who have a weakened immune system from covid-19. This first part aimed to find out:

1. how many people in the study have antibodies after having at least 3 COVID-19 vaccines,
2. what common factors are present in people who don’t have antibodies.

This information will help plan better care, treatment and services for people living with these conditions.

There is a second part of the study that aims to find out if having antibodies reduces the chance of having COVID-19 and becoming very ill with it. This part of the study is on-going. We will share those results as soon as they are available.

How did they do the research?

The research included 28,411 immunocompromised people who had received at least 3 covid-19 vaccines. This included people with:

• a rare autoimmune rheumatic disease such as lupus, vasculitis, myositis, or scleroderma (6,516 people),
• a solid organ transplant (9,927 people), or
• a type of blood cancer affecting the lymphocyte blood cells (6,593 people).

 

Participants each did a home blood finger-prick test for antibodies, and the researchers studied what factors might be linked to having antibodies, or not having antibodies, after at least 3 doses of a covid-19 vaccine.

Results

Main results:

• About 4 in 5 people with a solid organ transplant, rare autoimmune disease, or blood cancer affecting lymphocytes had antibodies after having 3 or more vaccines.
• People who had more doses of vaccine were more likely to have antibodies.

 

More detailed results:

• 29% of participants had 3 vaccines, 62% had 4 vaccines, and 10% had 5 or more vaccines at the time of their test.
• Antibodies were found in 77% of people who had a solid organ transplant, 79% of those with a blood cancer, and 86% with rare autoimmune disease.
• People were more likely to have antibodies if they were younger, had more vaccine doses, and had previously had COVID-19. Some medications that weaken the immune system reduced the likelihood of having antibodies.

 

 

Conclusions and recommendations

This study suggested that most immunosuppressed people make antibodies after having at least three covid-19 vaccines. It also suggested that the more vaccines you have, the more likely you are to have antibodies. Because of this, the researchers recommended people have vaccines and booster doses to increase their likelihood of developing antibodies to covid-19.

The researchers also suggested that the finger-prick test could be useful tool to identify people who have no protective antibodies. This could enable them to have quick access to treatments to prevent infection and if they have a covid-19 infection.

What happens next?

The next part of the study is investigating if having antibodies reduces the chance of getting covid-19 and becoming very ill with it. The research team is working on this now.

Where can I read more?

You can read the full scientific paper here: Antibody prevalence after three or more COVID-19 vaccine doses in individuals who are immunosuppressed in the UK: a cross-sectional study from MELODY

Follow the study on X (Twitter) here: https://twitter.com/MELODYStudyUK