Study Reinforces Rubella Vaccine Warnings for Patients with Immunodeficiency Disorders

A new study confirmed safety warnings addressing the rubella vaccine and its harmful effects on individuals with primary immunodeficiency diseases (PIDD).

PIDD is a diverse group of rare, chronic disorders with genetic origins, characterized by malfunctions in the body’s immune system, according to a study published in the Journal of Allergy and Clinical Immunology. While a majority of patients with these diseases have recurrent infections and other health issues, some also have cutaneous granulomas.

The rubella vaccine, which is usually administered as part of the measles-mumps-rubella (MMR) vaccine, has been thought to put PIDD patients at risk for infection. In the new study, researchers were able to provide concrete evidence of this effect.

“Up to now, the risk of adverse effects from rubella vaccine has been a theoretical concern for many immune deficient patients,” said lead researcher Kathleen E. Sullivan, MD, PhD. “The vaccine’s package insert states that it shouldn’t be given to immune-deficient individuals. Our new study found genuine evidence of harm in a subset of patients with these rare disorders.”

Since prior studies only had smaller case reports showing vaccine-related rubella virus in granulomas of PIDD patients, researchers chose to analyze data for a larger group of 14 patients with different PIDDs who had cutaneous granulomas.

Of the 14 patients, 12 were from the national registry of American PIDD patients called USIDNET, and the other 2 were from the European outreach. Four patients were adults and the rest were children.

The results of the study showed that 3 of the 11 children died from severe infections, and of all the patients analyzed, 7 had evidence of rubella virus antigen in their granulomas.

The findings suggest that since PIDDs compromise a patient’s immune system, it results in them being unable to clear out the weakened rubella virus in the vaccine, according to the authors. Thus, causing the virus to remain in the body can damage skin cells and lead to ulcers.

“This research reinforces the warning already found in rubella vaccine package inserts,” Sullivan said. “It gives additional guidance to physicians and families as to who should be restricted from the MMR vaccine. All of the patients with this complication had pretty severe immune compromise of their T cells — the cells responsible for clearing viral infections.”