In a new study, children who received the measles-mumps-rubella (MMR) vaccine were not at increased risk of developing serious bacterial infections. In fact, there was some evidence that children given the triple vaccine had a lower-than-normal risk of serious bacterial infections.

"Parents who are seeking to have single measles, mumps and rubella vaccines for their children because of fears that the combined vaccine is putting too much stress on the immune system should be very reassured by this new evidence," the study's lead author, Dr. Elizabeth Miller, told Reuters Health.

Miller explained that some parents have been concerned that giving three vaccines in a single shot "may be too much for the immune system to cope with." Some parents prefer to have their children receive the three vaccines separately to protect against "immune overload," according to Miller, who is with the Public Health Laboratory Service in London.

If the MMR vaccine does overwhelm the immune system, then vaccinated children should be more likely to develop infections in the months after vaccination. That was not the case in a group of several hundred children studied by Miller's team.

All children in the study had developed a serious bacterial infection, such as bacterial meningitis and septicemia, within three months of receiving the MMR vaccine.

The odds that a child would develop a serious bacterial infection after getting an MMR shot were no higher than expected, given the normal number of cases among children their age living in the same area. In fact, vaccinated children seemed to have a lower risk of some infections, particularly pneumonia, according to the report in the journal Archives of Disease in Childhood.

"While there were already strong scientific arguments against the idea that the immune system could be overloaded, our study provides direct evidence that this does not occur," Miller said.

The safety of the MMR vaccine has also come under scrutiny because of fears that the vaccine may increase the risk of autism. Despite these concerns, several studies have not detected a link between the vaccine and autism.

Wyeth Lederle, GlaxoSmithKline, Chiron and Baxter provided funding for the study.

SOURCE: Archives of Disease in Childhood 2003;88:222-223.