The measles vaccine may provide additional benefits beyond protecting children from the highly contagious and sometimes fatal disease.
According to a new study, by blocking the measles infection the vaccine may also prevent measles-induced immune system damage that makes children much more vulnerable to other infectious diseases for two to three years after immunization.
The immune system has the advantage of having “cellular memory” for previous infections to help fight invading microbes.
The study focused on a phenomenon called "immune amnesia" in which the measles infection destroys cells in the immune system that remembers previously encountered pathogens.
Prior research had suggested that “immune amnesia” typically lasted a month or two. The new study, based on decades of childhood health data from the United States, Denmark, England and Wales, showed the measles-induced immune damage persisted on average for 28 months.
Because of the long-term damage to the immune system by the measles infection, children that were not vaccinated and got the measles were more likely to die from other infections.
"The work demonstrates that measles may have long-term insidious immunologic effects on the immune system that place children at risk for years following infection," said Princeton University infectious disease immunologist and epidemiologist Michael Mina, whose study appears in the journal Science.
"The work also demonstrates that, in these highly developed countries prior to the introduction of measles vaccine, measles may have been implicated in over 50 percent of all childhood infectious disease deaths."
Measles was declared eliminated in the United States in 2000, but increasing numbers of cases have been reported in recent years, as more people remain unvaccinated. Last year's 668 U.S. measles cases were the most since 1994, the Centers for Disease Control and Prevention said.
"Our work reiterates the true importance of preserving high levels of measles vaccine coverage as the consequences of measles infections may be much more devastating than is readily observable," Mina said.
The study provided data showing that measles prevention through vaccination lowered childhood deaths from the pathogens that cause conditions such as pneumonia, sepsis, bronchitis, bronchiolitis and diarrheal diseases.
The study comes as many parents opt out of the measles, mumps and rubella (MMR) vaccine for their children based on discredited claims about the vaccine's safety or for religious and other reasons.
The MMR vaccine has been thoroughly studied by scientists around the world and has been found safe for children. This new study shows that its benefits may last much longer than previously thought.
Source: Will Dunham, http://www.reuters.com/article/2015/05/07/us-health-measles-idUSKBN0NS23N20150507