WELL & GOOD
SINCE IT CAN TEMPORARILY SUPPRESS AN INFANT’S IMMUNE SYSTEM, THE MEASLES VIRUS IS BEING INCREASINGLY LINKED TO OTHER SERIOUS CHILDHOOD DISEASES
Ignoring the seriousness of measles has put the country in a difficult spot
MOST HEALTH INITIATIVES take time; benefits rarely are seen quickly. In 1963, health authorities must have thought one of the most contagious diseases on Earth would be eradicated within a decade. Before the introduction of the measles vaccine, an estimated 2.6 million died from the disease each year. Yet today, in the developing world, it’s still a major killer of children under five. In an unvaccinated community, each person who gets measles spreads it, on average, to 12 others. The virus can linger in a room for up to two hours after an infected person has left.
Thankfully, the vaccine is extremely effective, with two doses of the MMR (Measles, Mumps and Rubella vaccine) providing more than
99 per cent protection.
In the decades since the 1960s, demographers noticed something surprising — childhood mortality was declining in areas where measles was dying out. For a long time, this was credited to public-health improvements in water purification, toilets and sanitation, rubbish collection and disposal. Better nutrition even.
Then, data from the United States, Denmark, England and Wales from before and after widespread vaccination began, showed a corresponding decline in other childhood diseases that couldn’t be attributed to publichealth measures. When measles was flourishing in unvaccinated populations, up to half of all childhood deaths from infectious diseases were from non-measles infections that occurred following an illness with measles.
Not only did measles plummet once vaccine use became widespread, but cases of other diseases dropped as well as complications such as pneumonia and meningitis. In some regions, the decline was as dramatic as 50 per cent; in impoverished areas, it fell by as much as 90 per cent.
“We saw the whole overall baseline for childhood mortality drop precipitously,” says Harvard’s Michael Mina, an author of a 2015 study analyzing the decline.
“In essence, the measles vaccine seems to not only protect populations against measles, it seems to be keeping a slew of other infections at bay. And one way it may be doing this is through the prevention of ‘immune amnesia’. Vaccination does more than safeguard children against measles; it also stops other infections taking advantage of measles-induced immune damage.”
Measles not only weakens the immune system in the short term, the virus seems to wipe the immune system’s memory, causing the body to forget how to fight off things that it may have already conquered.
This vulnerability was previously thought to last a month or two. However, a new study shows that children may suffer from the immunological effects of measles for up to three years, leaving them highly susceptible to a host of other serious illnesses.
The unwelcome epidemiologic evidence shows that measles may put the body into a much longer-term state of “immune amnesia”, where essential memory cells that protect the body against infectious diseases are partially wiped out. Secondary disease is common after the measles as not only does the virus assault the immune system’s first line of defence and damage skin, respiratory and gastrointestinal tracts, it also seems to deplete other immunity reserves.
“The best predictor of non-measles deaths was the total number of measles cases during the prior three years,” Michael explains. In essence, if a child gets measles sometime during the next three years, they could die from something that would not have been fatal had they not been infected with measles.
“Our findings suggest that measles vaccines have benefits that extend beyond just protecting against measles itself,” he says. “It is one of the most cost-effective interventions for global health.”
“Herd” immunity, or community immunity, protects the general population, particularly children and adults who can’t safely be immunized and babies who are too young. Vaccination rates of at least 94 per cent are needed to prevent measles transmission in high-risk areas such as childcare centres and schools. Measles is so contagious that it is used as the indicator disease to show deficits in immunization coverage of all vaccinepreventable conditions, which means the problem goes well beyond measles.
New Zealanders are extremely fortunate; the health resources to end this misery are available to all. Unfortunately, the legacy of Andrew Wakefield’s fraudulent 1998 study, which suggested a link between MMR and autism, is still being cited as a reason against the vaccine. It was subsequently found that Wakefield had falsified patient data and laboratory reports and was struck from the medical register.
In March 2019, the results of a largescale, highly regarded Danish study found no evidence of any connection between autism and the MMR vaccine, even among at-risk individuals.
“The study strongly supports that MMR vaccination does not increase the risk for autism, does not trigger autism in susceptible children, and is not associated with the clustering of autism cases after vaccination. It adds to previous studies through significant additional statistical power and by addressing hypotheses of susceptible subgroups and clustering,” claimed the research’s authors.
‘Our findings suggest that measles vaccines have benefits that extend beyond just protecting against measles itself’