Vaccination against COVID-19 prevents severe illness among people with a rare autoimmune disorder

Disease and treatment 2. nov 2023 3 min Professor Anette Wolff Written by Kristian Sjøgren

New research shows that people with autoimmune polyendocrine syndrome type 1 (APS-1) who are vaccinated against COVID-19 develop a good immune response and avoid severe COVID-19 illness.

When COVID-19 struck globally, getting vaccinated was natural for many people who did not want to become ill, miss work days or infect other people.

However, vaccination was more important for some people than for others. This included people with APS-1, a rare autoimmune syndrome in which a genetic disorder causes the body to attack the immune system.

The conclusion arises from a new study showing that vaccinating people with APS-1 against COVID-19 not only developed antibodies against SARS-CoV-2 but also prevented them from having a severe and potentially fatal outcome.

The results are therefore very positive.

“This is important news for people with APS-1, since they can have a very severe illness trajectory with COVID-19. We can now tell them that vaccination against COVID-19 can minimise the potentially severe harm COVID-19 could cause them because they have APS-1,” explains a researcher behind the study, Anette Wolf, Professor, Department of Clinical Science, University of Bergen, Norway.

The research has been published in iScience.

The body attacks its own immune system

APS-1 is a rare disorder caused by mutations in the autoimmune regulator (AIRE) gene. This gene encodes a protein that normally enables the body’s immune cells to distinguish its own cells from foreign cells.

The mutations cause the body to develop antibodies against the immune system’s interferons, which are important for antiviral immune response.

The immune system of people with APS-1 destroys the hormone-producing systems in the body, and they have poor immune response against certain fungal infections.

“In connection with the first waves of COVID-19, studies also showed that people with APS-1 have severe illness trajectories. Until then, there was little focus on the fact that viral infections could be particularly dangerous for these people,” says Anette Wolff.

38 people with APS-1 included

Because COVID-19 can be dangerous for people with APS-1, the researchers decided to investigate the effect of COVID-19 vaccination by obtaining blood samples from 38 people with APS-1 from the Norwegian Registry for Organ-specific Autoimmune Disorders – before they were vaccinated for the first time and between the various booster vaccinations.

The researchers asked the participants to answer questions about vaccination and infection. For example: Did they have COVID-19? When? What symptoms did they experience?

“We need to know whether vaccinating these people creates an immune response and whether this immune response affects the risk of a severe COVID-19 trajectory. Perhaps they could not make antibodies against SARS-CoV-2 and vaccination therefore would not reduce their risk of a severe outcome,” explains Anette Wolff.

None severely ill after vaccination

All but one of the 38 participants were vaccinated against COVID-19, and 24 (66%) developed COVID-19 during the study period based on symptoms and a positive PCR or rapid antigen test.

However, the COVID-19 trajectory was not as severe as feared among the vaccinated participants.

None experienced severe illness, and only two were hospitalised. Anette Wolff says that the two hospitalisations did not result from severe illness but from concern about the potential for severe illness.

Blood tests showed that people with APS-1 can establish a good antiviral response when vaccinated against COVID-19.

Compared with healthy controls, the participants did not produce as many antibodies to SARS-CoV2 in their blood, but the levels were sufficient to protect against COVID-19.

However, the researchers also found that the levels of protective antibodies reached the lower threshold for an adequate antiviral response more rapidly, since they started from a lower level.

“We have found the same phenomena among frail older people, who need booster vaccination more often than other people. People with APS-1 are therefore recommended to be vaccinated regularly, especially because the vaccination works for them,” says Anette Wolff.

Omicron may have affected the severity of COVID-19

Anette Wolff says that most of the participants developed COVID-19 after they had been vaccinated two to three times and that everyone who had COVID-19 experienced only mild to moderate symptoms.

She emphasises, however, that they developed COVID-19 during a period when the Omicron variant dominated, which means that the illness trajectories may have differed from the periods with the Alpha and Delta variants, which caused more severe illness.

“When the pandemic struck and we had access to vaccination, we contacted our APS-1 patients and said that getting vaccinated was a good idea. This study shows that this is still valid today, because we provide evidence that the vaccination works and probably helps them avoid becoming severely ill with COVID-19. This is important knowledge for people with APS-1, just as results from the previous studies are also important because they showed how serious it can be when unvaccinated people with APS-1 develop COVID-19,” concludes Anette Wolff.

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