Measles Frequently Asked Questions

Measles is considered one of the most contagious viruses known to humans. It has a reproductive number, or R0, of 12-18, which means that if a single individual has measles another 12-18 individuals will also become infected. In most people, measles will cause fever, rash, fatigue, preceded by cough, pink eye (conjunctivitis) and cold symptoms.

Unfortunately, measles is a serious infection (and with a high rate of complications), especially in infants under the age of 12 months not yet old enough to receive their first dose of measles vaccine. According to the Centers for Disease Control and Prevention, about one in four infected individuals will require hospitalization, and one in 20 will experience measles pneumonia, which often requires an admission to the hospital Intensive Care Unit. In some cases, measles can also cause deafness and other neurologic complications.

Measles was eliminated from the U.S. in 2000 and then in the Western Hemisphere in 2016. Unfortunately, it has now returned due to pockets of declining vaccine coverage, especially in the 18 states that allow nonmedical vaccine exemptions for reasons of personal and philosophical belief. This decline is the result of an aggressive and well-organized and funded anti-vaccine movement that began in 1998.

There have been more than 1,000 cases of measles reported in the U.S. in 2019, by far the most this decade. This year about 9% of people with measles have been hospitalized, including a fair number of admissions to the Intensive Care Unit.

In 2018, a group from the National School of Tropical Medicine at Baylor College of Medicine identified 15 urban “hotspot” areas where measles might erupt due to its finding that large numbers of kindergartners were being denied their vaccines. So far in 2019, measles has occurred in seven of those hotspot areas.

It began with a small study published in The Lancet, a British medical journal, in 1998 claiming that a dozen children who received the measles-mumps-rubella (MMR) vaccine subsequently developed colitis and then pervasive developmental disorder, the name then given to autism. However, the results were determined not to be valid, and a journalist from the Times of London uncovered findings that fraud was perpetrated. The paper was retracted in 2010, but that 12-year period allowed an anti-vaccine movement to begin.

The CDC publishes a recommended immunization schedule for both children and adults based on decades of clinical safety and efficacy studies. Children should receive their first MMR vaccine around one year of age, and then a second one, usually around the time of school entry or sooner. Most adults born after the year 1989 received two doses of the MMR vaccine as a child, while it’s believed that most adults born before 1957 probably had measles and are also immune. The grey zone is for adults born between 1957 and 1989 who likely received only one MMR vaccination or possibly a first-generation vaccine that was less effective than the current one.

For those individuals, the CDC is recommending that if you are in a high-risk category (see below) you should learn your measles immunization status either by testing to determine if you have measles antibody titers, or simply getting vaccinated with the MMR vaccine through your physician or pharmacy. High-risk groups include healthcare providers, international travelers or those living in an area where measles transmission is underway. Women who are pregnant or might be pregnant should also consult with their obstetrician. 

Harris County Public Health has been conducting outbreak investigations whenever measles cases appear in Houston and outlying areas. Recently, the CDC and the U.S. Department of Health and Human Services have mounted a coordinated response to combat vaccine hesitancy and refusal. There are also two nonprofit community organizations in Houston – the Immunization Partnership and Children at Risk – that are speaking with elected officials and community leaders about a more coordinated response in the state of Texas. Unfortunately, Texas has the highest numbers of nonmedical vaccine exemptions of any state, so our state is highly vulnerable.

By some accounts, there are an estimated 500 anti-vaccine misinformation websites online, all amplified on social media and e-commerce platforms. Therefore, you have to be careful! 

We encourage you to educate yourself and others. Talk to your pediatrician and consult vaccines.gov and cdc.gov for reliable information.