(RxWiki News) It makes sense that the vaccine designed to protect kids against measles, mumps and rubella does just that. But it may do even more.
A recent study found that children who received their MMR vaccine on time had lower hospitalization rates for infectious diseases than those who didn't.
All the children in the study had received their other recommended vaccines, so the reduced risk appeared directly related to the MMR.
Hospitalization related to upper respiratory infections in particular were lower for children who had received their MMR on time.
"Discuss the recommended immunization schedule with your child's pediatrician."
The study, led by Signe Sorup, PhD, of the Research Center for Vitamins and Vaccines at Copenhagen's Statens Serum Institut, looked at whether receiving the MMR vaccine led to reduced hospitalizations from other conditions.
The researchers tracked 475,262 children who had been born in Denmark between 1997 and 2006.
They were followed from when they were 11 months old up until age 2, and the researchers used their medical records to get data on hospitalizations and vaccinations.
The Danish recommended schedule for vaccines suggests children receive the DTaP (diphtheria, tetanus, pertussis), IPV (polio) and Hib (Haemophilus influenzae type b) vaccines when children are 3, 5 and 12 months old.
Then, when children are 15 months old, it is recommended that they receive the MMR.
During the nearly decade-long study, there were 43,207 admissions to the hospital among the children for any type of infection.
The children's risk of hospitalization was separately analyzed for two different groups: those who received the MMR after their third dose of DTaP-IPV-Hib, and those who received the MMR after their second dose of DTaP-IPV-Hib.
The researchers found that approximately nine children who had received the MMR vaccine after their third dose of DTaP-IPV-Hib were admitted to the hospital for an infectious disease each year.
Yet, 12 children per year were hospitalized among those who received their third dose of DTaP-IPV-Hib but not received the MMR on time.
Receiving the MMR therefore reduced those children's rate of being admitted to the hospital by 14 percent.
Meanwhile, among a smaller group receiving the MMR after their second dose of DTaP-IPV-Hib (before the third dose), only 10 were hospitalized per year for infections, compared to 13 per year among those who had not received their MMR.
Another way of looking at the data, children aged 16 to 24 months old had a 4.6 percent risk of hospitalization for an infectious disease if they had received the MMR on time, but a 5.1 percent risk of hospitalization if they had not received the MMR on time.
For every 201 children who were vaccinated on time with the MMR (before 16 months old), one child would be prevented from being admitted to the hospital for an infectious disease.
In particular, children experienced respiratory tract infections at a rate 20 percent lower if they had received the MMR on time than if they had not.
All these findings remained after the researchers had adjusted for other factors, such as any chronic diseases the children might have, whether they had been in the hospital in the past month, whether they had been hospitalized before 11 months old, their parents' origin and other children in the home.
The researchers also looked closely at the hospitalization rates based on the number of days since the MMR to see if healthier children were simply being vaccinated sooner than other children.
However, an analysis of the time frames involved in vaccinations and hospitalizations ruled out this possibility.
Thomas Seman, MD, a pediatrician at North Shore Pediatrics in Danvers, Mass., said the study's findings are very interesting.
"The study demonstrates that the body, once activated by a live vaccine/infection, is activated to continue and improve its monitoring of the entire body and deal with further infections," he said. "The benefits of fighting infections with vaccines is further validated."
The effect appears particularly pronounced with live vaccines, as in this case of the MMR, Dr. Seman added.
"Live vaccines, with their persistent effects, seem to be more of a stimulant to the child's immune system but to a degree greater than would be expected," he said. "Further studies to verify this and hopefully help explain the effect so that it can be utilized further are needed.
The study was published February 25 in the journal JAMA. The research was funded by the Health Foundation, the Rosalie Petersen Foundation and the Novo Nordisk Foundation.
The institution also received support from the Danish National Research Foundation. The authors reported no conflicts of interest.