Why are measles outbreaks on the rise, even in places where the vaccine is readily accessible? Am I safe as long as I’ve been vaccinated? Everyday Einstein investigates.
In 2018, there were 292 cases of measles from 16 outbreaks reported in 26 states in the United States. That’s twice the number from the previous year. There have also been a growing number of outbreaks in Europe, with the largest numbers of reported cases and deaths in Bulgaria, France, Germany, Romania, Spain, and Switzerland. In 2017, 14,451 cases of measles were reported in Europe, which is more than three times the number of cases the year before.
So why are measles outbreaks on the rise, even in places where the vaccine is readily accessible? People used to get measles all the time so so surely it can’t be that big of a deal to come down with measles, right? Am I safe as long as I’ve been vaccinated?
What are measles?
Measles is an infection caused by a virus which carries common symptoms like fever, cough, runny nose, and sore throat, as well as a skin rash characterized by large, flat botches covering the body. The incubation period (the time from when you get measles until you show symptoms) lasts 10-14 days before the rash begins on the face and starts to spread downward. Anyone with measles is most contagious starting around 4 days before the rash appears and lasting until four days after the rash has been present.
Since measles is a viral infection, there is no specific treatment or cure other than waiting for your body to fight off the virus. And that battle is more easily won by those of us with stronger, more developed immune systems.
How common are measles?
Measles is one of the most contagious diseases in the world meaning that 90% of people who are vulnerable to contracting measles will get the disease if exposed. The disease can be spread by an infected person coughing, sneezing, or even talking, which sends infected saliva into the air to be inhaled by another person. Measles can also live on surfaces for up to 2 hours.
People who choose not get vaccinated against the measles are the most likely cause for the return of these major outbreaks.
Before the measles vaccine, almost everyone got measles as a child. In the United States, 48,000 people were hospitalized, 1,000 contracted measles-related encephalitis (a swelling of the brain), and 400-500 people died each year due to measles. Globally, there were 2.6 million measles-related deaths each year. Author Roald Dahl’s daughter Olivia lost her life to encephalitis in 1962 at the age of 7, just one year before the vaccine became available.
Since the vaccine was introduced in 1963, that number has dropped to 100,000 deaths each year from measles worldwide. The measles vaccination led to an 80% drop in measles-related deaths from 2000 to 2017 worldwide, which amounts to an estimated 21 million deaths that were prevented.
Measles was even declared eliminated in the United States in 2000, meaning there was an absence of continuous disease transmission for more than a year. In other words, measles outbreaks in the United States now involve someone bringing the disease with them from other countries.
However, the number of measles outbreaks in the United States and Europe, and thus the number of individuals contracting the disease, is now on the rise. If this rise were due to a decrease in the vaccine performance over time, we would expect to see higher rates of measles among older people—which is not the case.
People who choose not get vaccinated against the measles are the most likely cause for the return of these major outbreaks. To prevent an outbreak, at least 90-95% of the population must be vaccinated so that the disease isn’t given a chance to spread, a concept known as herd immunity. Those who cannot get vaccinated, for example, those with a compromised immune system due to other illnesses like leukemia, those with vaccine-related allergies, or very young children, thus rely on the rest of us to vaccinate.
Who gets the measles?
Most measles-related deaths worldwide are children under 5 years old. In fact, since you can only get measles once, most people born or living in the United States before 1957 are immune because they have very likely already had it. The vast majority (around 70%) of people in the United States and Europe who get come down with measles once exposed are unvaccinated. Especially vulnerable are unvaccinated young children and unvaccinated pregnant women.
Those who elect not to vaccinate for measles also put vaccinated people at a higher risk. That’s right—you can still get measles even if you are vaccinated. Remember the measles outbreak that originated at Disneyland in 2014? Six of the 52 cases of measles related to that outbreak were people who had been vaccinated.
So what gives?