(RxWiki News) Some parents may worry about certain vaccines if their child has a chronic condition, such as asthma, arthritis and diabetes.
Parents of children with juvenile idiopathic arthritis may feel reassured by a new study about the MMR vaccine. MMR stands for measles, mumps and rubella.
The study found that the vaccine did not worsen children's arthritis, but it did protect them against measles, mumps and rubella, as it is supposed to.
The study confirmed the safety and effectiveness of the MMR vaccine for children with juvenile idiopathic arthritis.
"Ask your pediatrician about necessary vaccines for your child."
The study, led by Marloes W. Heijstek, MD, of University Medical Center Utrecht at Wilhelmina Children’s Hospital in the Netherlands, looked at the safety and effectiveness of the MMR vaccine for patients with juvenile arthritis.
Arthritis is an autoimmune disease, which means it results in part from a weakened immune system that attacks itself.
Vaccines work by stimulating the immune system. Therefore, the researchers wanted to see if the vaccine affected the activity of a disease related to the immune system.
The researchers randomly divided 137 patients, aged 4 to 9, with juvenile idiopathic arthritis into two groups.
One group of 68 patients received the MMR booster vaccine. The other 69 patients did not receive the booster vaccination. All the patients had previously received their first MMR vaccine.
Any patients taking biological therapies for their arthritis discontinued them well ahead of the vaccination so that it did not affect the results.
The researchers used an assessment called the Juvenile Arthritis Disease Activity Score to measure the children's disease activity, or how much their arthritis was acting up.
The activity scores range from 0 (no activity) to 57 (high activity, lots of bad symptoms).
The researchers compared the disease activity scores for both groups during the year after the vaccinations.
They also tested those who received the vaccine for MMR antibodies one year after getting the shot.
Vaccines work by forcing the body to make antibodies (white blood cells that fight disease) for the specific diseases that the vaccine protects against.
If the children had high levels of MMR antibodies, that meant the vaccine was effective.
In the year of follow-up, the disease activity between those who received the vaccine and those who did not was not very different.
The children who received the booster vaccine had an average arthritis disease activity score of 2.8, and those who did not get the booster had an average score of 2.4.
As the scale ranges from 0 to 57, the difference of 0.4 was considered too small to be significant.
One year after the vaccinations, the children who received the boosters had higher antibodies concentrations than the kids who did not.
The children who got the booster had twice as many measles antibodies, about 62 percent more mumps antibodies and about 53 percent more rubella antibodies.
The researchers also measured the children's seroprotection for measles, mumps and rubella. Seroprotection is how much protection the vaccine provides to the individual.
One year after the vaccinations, the children who got the booster had 100 percent protection against measles, compared to 92 percent protection for those who didn't get the booster.
Those who got the booster had 97 percent protection from mumps, compared to 81 percent protection in those who didn't get the booster.
Those who got the booster had 100 percent protection against rubella, compared to 94 percent for those who didn't get the booster.
Therefore, the researchers concluded the MMR booster shot was effective in boosting the immune system for the patients who received it. These patients did not suffer worse symptoms in their arthritis from the MMR shot.
The study was published June 18 in JAMA. The research was funded by the Dutch Arthritis Foundation and the Dutch League Against Rheumatism.
One author has received funds from Roche, AbbVie, Novartis and Pfizer for research, consulting, honoraria and/or advisory board membership. The other authors reported no potential conflicts of interest.