Feature
A Brief History of Measles and Its Vaccines
Why the "wildfire disease" still remains a serious global threat
1917 was one of the worst years on record for measles in the United States. There were more than 600,000 reported cases that year, and probably at least 2 million more that went unreported. Epidemics swept the country, exacerbated by wartime mobilization that crowded thousands of men together in Army camps or troopships.
Today, measles is like an unwanted houseguest, clinging to the doorframe and stubbornly refusing to be evicted. Efforts to eliminate the disease keep falling short due to incomplete vaccination — made worse in recent years by vaccine hesitancy and the anti-vaxx movement.
Let’s take a closer look at this frustratingly persistent disease and the vaccine that could eliminate it once and for all.
Measles Rap Sheet
Named for the distinctive rash and small red pustules it creates (called “maselen” in Middle English), measles is a systemic viral infection spread by respiratory droplets. Like many viral infections, it becomes contagious days before most patients realize they have it.
Because the virus can survive in the air or on surfaces for up to two hours, measles is extraordinarily contagious, able to sweep through nonimmunized populations with breathtaking speed. The virus’s basic reproduction number can be 12 or higher, meaning that a single infected patient can potentially infect more than a dozen other people, especially in crowded conditions like schools or military camps.
Many Americans now think of measles as a harmless nuisance, but even today, three cases in 10 will suffer some type of complication, which can include diarrhea and secondary infections like otitis media or pneumonia. There are also rarer, riskier complications, like immune thrombocytopenic purpura (ITP), an autoimmune disorder that interferes with blood clotting.
About one in every 1,000 measles cases results in acute encephalitis, which carries a significant risk of death or lasting neurological impairment.
For people already suffering from poor nutrition or immunodeficiency, measles can be devastating, especially if those patients can’t access treatment for potentially deadly secondary infections. In such conditions, the World Health Organization (WHO) says the case-fatality rate for measles can be as high as one in 10. Worse, there’s still no cure or effective treatment other than basic supportive care.
That’s why measles remains a serious global health threat. According to WHO, measles killed 109,638 people worldwide in 2017. Most of the dead were young children.
Inoculation Quest
In the winter of 1755, a Scottish physician, Francis Home, M.D., made the first known attempt to vaccinate patients against the measles. Home recognized, as physicians had for centuries, that measles survivors acquire an immunity to the disease.
As a measles epidemic swept Edinburgh, he cajoled and/or bribed a dozen sets of parents into letting him inoculate their children using blood from measles sufferers in the late stages of infection. Home hoped this would prevent the children from being becoming infected themselves.
This experiment had some success, but not enough to convince Home’s very skeptical patients that it was worth the risk. His next attempt, using nose swabs rather than blood, was not successful at all, and he soon abandoned the effort.
Although Home’s methods were crude, his theory was fundamentally sound. The measles virus, unlike fast-mutating influenza, is highly conserved. There are distinct strains (which modern epidemiologists can now identify and track quite accurately), but their antigenic effect is about the same.
