AFMC Blog

What You Need to Know About Measles Outbreaks

Written by Anne Wasson | Mar 8, 2019 9:21:02 PM

Measles was eliminated from the United States in 2000. Then why are we having measles outbreaks? There were 17 different measles outbreaks in 2018. So far this year, the Centers for Disease Control and Prevention (CDC) reports 206 people have been infected nationwide, across 11 states.

Most of those infected live in areas where there are pockets of parents who refuse to or delay vaccinating their children. The Pacific Northwest has an especially vocal group of parents that forego vaccinations (“anti-vaxxers”), according to the Associated Press. Oregon and Washington are two states that permit parents, for personal or philosophical reasons, not to vaccinate their children.

The CDC blames most of the recent measles cases to a failure to vaccinate children. While the vaccination rate for measles was about 94 percent for kindergartners in the 2017-18 school year, this is the third year in a row that the exemption rate has increased nationwide.

The CDC says most measles cases (80%) come into the United States from other countries. Measles is still a common disease in many parts of the world, including Europe, Asia and Africa. It kills about 90,000 people every year worldwide.

When someone brings the measles virus into the country, it can spread rapidly among people who have no immunity to it. This is often the case in communities where groups of people or families have not been vaccinated because of philosophical or religious beliefs.

A measles outbreak can happen quickly because the measles virus is highly contagious. It is spread through the air when an infected person coughs or sneezes. Symptoms start with a fever, then a cough, runny nose and red eyes. This is followed by a rash of tiny red spots, starting at the head and spreading downward.

Effective vaccine available

A safe and very effective (97% with two doses) vaccine can prevent measles. The MMR vaccine (protects against measles, mumps and rubella or German measles) is given as a two-shot series. The CDC recommends that children get their first shot of MMR at 12 to 15 months of age. A second shot is required, between ages 4 to 6. Children may instead get the MMRV vaccine that adds protection against varicella (chickenpox) to the MMR shot. MMRV can only be given to children who are 1 to 12 years of age.

Most cases of measles in the United States originate overseas. If you plan to travel outside the United States with an infant, you need to take extra precautions. The first MMR shot is safe to give early, at six months of age. The second shot can be given at 12 months or older, in two doses and given at least 28 days apart.

Vaccines are very safe overall and side effects are extremely rare. The tiny risk of side effects must be weighed against the protection provided to individuals and the community. Research has proven that the benefits of vaccines far outweigh the risks of a bad reaction to the vaccine. If there are side effects to the vaccine, in most cases they completely resolve on their own. This contrasts starkly with the natural infections that vaccines are designed to prevent. Contracting the illness due to failure to vaccine can reduce the quality of life through permanent conditions such as blindness, deafness, developmental delay, epilepsy, paralysis or even death.

Measles can cause serious illness

Measles should not be thought of as a harmless childhood illness. Before the measles vaccine was widely used, starting in 1963, about four million Americans a year had measles. This resulted in 48,000 hospitalizations, including about 1,000 cases of encephalitis (swelling of the brain) and about 500 deaths a year.

It can be especially dangerous for children and adults who have not been vaccinated and for those who cannot be vaccinated because of other health conditions (HIV/AIDS, type 1 diabetes, cancer or a weakened immune system).

Nationwide about 2.2 percent of parents choose not to vaccinate their children; about 5 percent choose to delay the vaccine schedule. A study of measles infection in the United States during 1985-1992 reported that infection was 35 times greater in children with vaccine exemptions, when compared to vaccinated children.

Herd immunity and free choice

The health of everyone in the community depends on the health of each individual. Vaccinations protect both individuals and the community. Thus, a single unvaccinated child can risk the health of all his or her neighbors.

Why not let children develop immunity naturally, like they did before the vaccine was available? Because measles can become a serious disease requiring hospitalization, disability or even death.

Non-medical exemptions, including personal or philosophical exemptions, have grown dramatically during the past 10 years. In states that only allow religious exemptions, the number of exemptions have remained the same, about 1 percent of the population. Several states are considering eliminating all vaccine exemptions. Other states want to keep religious or medical exemptions but eliminate all others.  Unvaccinated children are more likely to be male, white, belong to households with higher income, have a married mother with a college education, and live in a family with four or more children.

Community immunity (also called herd immunity or herd protection) varies by disease. Generally, it takes from 83 to 94 percent of people to be vaccinated to achieve community immunity. When enough people in a community are vaccinated against a disease, the germs can’t spread as easily from person to person, making the whole community less likely to get the disease. Eventually the disease becomes rare and is sometimes wiped out.

While herd immunity protects everyone, it is especially important for those who cannot be vaccinated due to their medical condition or who have a weak or failing immune system. Community immunity continues to protect us only if children continue to be vaccinated. Immunity levels among adults is also a consideration if there is an outbreak.

Are you protected against measles?

Measles immunity can be established through a MMR shot, laboratory confirmation of having had measles or lab testing that shows immunity. Anyone born in the United States before 1957 is also considered immune. However, it is now known that the vaccine made with killed measles vaccine, available between 1963 and 1967, was not effective. That’s why adults, most especially women who are planning to become pregnant, should have their immunity checked. They may need a booster shot to establish immunity. Once you have immunity, booster shots are generally not needed.

Any teenager or adult who has no evidence of immunity, as described above, should have two MMR shots, given at least 28 days apart. Adults may only require one shot.

Two doses of MMR are 97 percent effective against measles, 88 percent effective against mumps and 97 percent effective against rubella. The MMR vaccine is a weakened but live virus that causes a harmless infection in the vaccinated person. Very few, if any, symptoms occur as the body fights the infection and immunity develops.

The CDC cautions that people with any of the following health issues should not be vaccinated:

  • Had a life-threatening allergic reaction to the antibiotic neomycin or any other part of the MMR vaccine or a severe allergic reaction to their first MMR shot
  • Pregnant women; women should not get pregnant for four weeks after getting the MMR shot
  • HIV/AIDS or any disease affecting the immune system
  • Being treated with drugs that affect the immune system such as steroids
  • Have cancer of any type or are being treated for cancer with radiation or drugs
  • Ever had a low platelet blood count
  • Received another vaccine within the past month
  • Received a transfusion or other blood products recently
  • Current illness – wait until you recover to have the shot

In case of an outbreak near you

If you do not have immunity against measles, mumps or rubella and are exposed to someone with one of these diseases, ask your doctor if you need a MMR vaccine. Getting an MMR shot within 72 hours of being exposed may provide some protection. It’s not harmful to get the shot and may also prevent getting these diseases in the future.

If there’s an outbreak, everyone without immunity should be brought up to date on their MMR shots. That’s why it’s good for adults, including students heading off to college, to have their doctor check their immunity and get a booster shot, if needed. The CDC considers an outbreak to be three or more cases in one area.

Most health insurance will pay for vaccines. The Vaccines for Children Program may pay for children’s vaccines if the child (up to age 18) does not have insurance. This is a federally funded program that provides free vaccines for children if their parents cannot pay for them. Visit this site to find out if your child is eligible.

 

Photo credit: CHBD   E+ Collection