Measles and Measles Prevention

What is measles?

Measles virus (MeV) is a respiratory virus. It belongs to the paramyxovirus family. The virus is found specifically in humans. Measles is very contagious. It spreads when a healthy person comes into close contact with an infected person’s bodily fluids. For example, if a person with measles coughs or sneezes, people nearby can get measles too. 
Measles often starts with a high fever. It usually starts 10 to 12 days after you are first exposed to the virus. Next, you’ll get a sore rash of red-brown spots all over your body. Measles puts your body at risk of other lung infections, such as bronchitis and pneumonia. In rare cases, it can even cause encephalitis (an infection of the brain) and death.

Sounds terrible, doesn’t it? Fortunately, measles is preventable. In fact, in Canada, measles has been preventable for over 50 years. This is thanks to the measles vaccine. Let’s learn what the vaccine is, its history, and why it is so important. 

What is the history of the measles vaccine?

First, in 1954, two scientists isolated a strain of the measles virus. The scientists were named John Enders and Thomas Peebles. John Enders was a virologist and Thomas Peebles was a pediatrician.

Next, Enders developed a method of culturing the virus. Culturing is a term for growing and multiplying microorganisms such as bacteria and viruses. Once the virus was growing, scientists needed to find a way to attenuate the virus. In other words, they needed to weaken the virus’ ability to make people sick. To do this, Enders  developed a method called serial passaging. 

In the serial passaging method, the scientist first cultures the virus in one environment. Then, the scientist removes part of the virus and cultures it in a different environment. The scientist does this over and over again until the virus has mutated (changed) enough to be harmless. Then, scientists can use it to make a vaccine.

It took Enders and another virologist named Samuel L. Katz three years of work to create a measles strain that was safe for testing as a vaccine. Then, they spent seven more years testing the vaccine on animals and in clinical trials with humans. Finally, the measles vaccine was licensed.

Did you know? 

In 1954, scientists isolated a measles strain from a 13-year-old named David Edmonston. It is called the Edmonston strain and is still used in vaccines today.

The measles vaccine was introduced in 1963. Within a few years, it had just about wiped out measles in North America. By 2011, the measles rate in the United States was 99% lower than before the measles vaccine. Canada has also seen similar results. 

In 1971, the first combination measles-mumps-rubella (MMR) vaccine became available in the United States. It was developed by the American microbiologist Maurice Hilleman. This MMR vaccine is a trivalent vaccine, which means it contains three virus strains. It used to be a single dose, but the single dose didn’t always prevent measles. Since 1997, it has been a two-dose vaccine. In 2005, chicken-pox immunity was also added to the mix. Since then, children get the measles-mumps-rubella-varicella (MMRV) vaccine.  

When do kids get the measles vaccine?

The World Health Organization (WHO) states that children should get their first dose of the measles vaccine between the ages of 12 months and 15 months. They should get their second dose after 18 months of age, but before they start going to school. 

Why is the measles vaccine important?

Some viruses can be treated with medication. That is not the case with measles. Most people will recover if they rest, eat healthy and drink plenty of fluids. But the best way to deal with measles outbreaks is to prevent them in the first place. 

How do you prevent measles outbreaks? With vaccination programs. Imagine a classroom. Almost all of the students students are vaccinated. One is not. But because all the other children have been vaccinated, the chances of the unvaccinated child getting measles goes down. This is true not only for classrooms, but for entire communities. If most people are vaccinated, then the chances of the people who aren’t vaccinated getting sick go down. This concept is called community immunity (or herd immunity).

Why do some people worry about the measles vaccine? 

Until 1997, the MMR vaccine was considered completely safe. But then, people began to worry that vaccines could cause autism. That’s because a doctor named Andrew Wakefield published a fraudulent research paper claiming there was a connection between autism and vaccines.  Since then, many scientists have completely discredited (proven wrong) his theory. And Wakefield is not a practicing doctor anymore.

But this fraudulent study had some dangerous effects. It led to anti-vaccination campaigns by various celebrities. It also led to a lot of misinformation in the media. All of this affected the public’s trust of vaccines. Some parents, dubbed “anti-vaxxers,” have chosen to not vaccinate their children. Because of this, there have been measles outbreaks in some communities that have been measles-free for a long time.

What are the effects of the measles vaccine?

As you learned, the vaccine has been available since 1963. But measles is still one of the leading causes of death in children under five years old. This is especially true in countries that do not have strong health care systems. There have been mass vaccination campaigns in these countries. The campaigns have had a powerful effect. The number of deaths worldwide due to measles dropped by 80% between 2000 and 2017. Scientists continue to focus on eradicating, or completely eliminating, the disease. 

Did you know? 

To date, only one human disease has been eradicated due to vaccination: smallpox.  

The measles vaccine is considered to be one of the greatest public health inventions of the 20th century. It will continue to be a key medical tool in controlling measles infections.