New research shows that the measles-mumps-rubella (MMR) booster vaccine works well in patients with juvenile idiopathic arthritis (JIA), and does not cause flares or otherwise worsen their disease, according study published recently in the Journal of the American Medical Association.  

Traditionally, JIA patients – who are immunosuppressed due to their disease and/or medication, such as methotrexate or biologics – have been warned against getting vaccines that contain a live virus, such as this one, out of concern they could get sick with the disease the vaccine is supposed to prevent. Furthermore, the safety has been questioned because small, uncontrolled studies have raised questions about whether the rubella component induces arthritis, although controlled trials have failed to establish this association.  

“Our trial unequivocally shows that MMR booster vaccination has no effect on JIA disease activity,” explains lead author Marloes W. Heijstek MD, in the department of pediatric immunology at Wilhelmina Children’s Hospital in Utrecht, the Netherlands. “JIA is a relapsing and remitting disease. The fact that a flare occurs after a vaccination does not necessarily mean that there is a causal relation between the flare and the vaccination. Our randomized controlled design enabled us to show that these flares after vaccination are coincidental… rather than causal.”

For the study, researchers recruited 137 JIA patients between the ages of four and nine who were on various different treatments including methotrexate (60 children), a biologic (15 children) and/or nonsteroidal anti-inflammatory drugs (74 children). Half of the children were randomly assigned to receive the MMR booster; the other half did not receive the booster and served as the control group. Patients were assessed every three months for a year.

After a year, children who had received the MMR booster had higher protection rates – as measured by blood concentrations of certain antibodies – against measles, mumps and rubella (97 to 100 percent) compared to those who had not (81 to 94 percent). Average disease activity scores – as measured by the Juvenile Arthritis Disease Activity Score including 27 joints (JADAS-27) – were virtually the same between the two groups.

Because the number of patients using biologic drugs was so small, the researchers can’t say for certain the MMR booster is safe for them, even though the results lean in that direction. “This needs to be studied in larger patient cohorts,” Dr. Heijstek says.  

The researchers write that they were also unable to draw firm conclusions about the effect of the MMR booster on JIA patients with high disease activity, since the majority of the patients in the study had low disease activity.

These results apply only to the MMR booster vaccine, which is generally given to children between the ages of four and six – not the primary MMR vaccine. However, the researchers say primary MMR vaccinations are not generally a concern for JIA patients because the vaccine is typically given during the first year of life, before the onset of JIA, which in the large majority of patients occurs after the age of two.

Daniel J. Lovell, MD, the associate director of the division of rheumatology at Cincinnati Children's Hospital Medical Center, in Ohio, notes that this study confirms the results of two earlier studies – and says it is important to see data accumulating on the effects of live vaccines in JIA patients.

“This is good news. It’s important information and I think based on the fact we now have three studies that all demonstrate the same thing, I would move forward and tell parents it is safe to do the MMR booster in children on methotrexate,” Dr. Lovell says. “I think it is encouraging news for patients taking biologics – but additional studies need to be done to confirm this for them.”

Dr. Lovell says it is important to stress that inactive vaccines are safe in all JIA patients, since the viruses are not live.