CDC 2017 survey shows Houston with lowest measles vaccination rate among key U.S.cities

Houston is ranked the worst metro area in the United States for percentage of children who are vaccinated with the measles vaccine, according to the Center for Disease Control and Prevention. >>>Which schools have the highest percentage of vaccine exemptions? Find out in the photos that follow... less Houston is ranked the worst metro area in the United States for percentage of children who are vaccinated with the measles vaccine, according to the Center for Disease Control and Prevention. >>>Which ... more Photo: The Editorial Board / Evensi.US Photo: The Editorial Board / Evensi.US Image 1 of / 17 Caption Close CDC 2017 survey shows Houston with lowest measles vaccination rate among key U.S.cities 1 / 17 Back to Gallery

A 2017 report by the Center for Disease Control and Prevention shows that among major U.S. cities surveyed, Houston has the lowest rate of measles vaccination among young children.

The study looked at vaccination rates among a large sample group of children between 19 and 35 months old in 2017, which was the most recent data available.

Health authorities announced this week that five Houston-area people, including two infants, have contracted measles. Measles is a dangerous and highly contagious disease that can cause lasting damage in some cases.

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In the 2017 study, the CDC claims 87.8 percent of Houston children in that age range were vaccinated against measles, mumps, and rubella vaccination, well below the statewide 90.3 percent.

The report included eight major U.S. cities, although data was not available for many of them.

Other Texas metro areas fared better. Bexar County lead the way with 96.1 percent of its children vaccinated.

For Dallas County, 93.1 percent of children were vaccinated. Travis County had 92.1 percent and El Paso County had 89.3 percent.

Nationally, Houston is listed as the fifth worst designated area for vaccine rates. It was beat out by the states of Colorado (87.2 percent), Indiana (87 percent) and Missouri (82.5 percent).

Guam, a U.S. territory, had the worst rate with 82.5 percent.

Massachusetts (98.3 percent) and Virginia (97.6 percent) took the top for designated areas in the study, followed by Bexar County.

These numbers are set up against a standard called herd immunity. According to the Oxford Vaccine Group, by being vaccinated an individual is not only protected from being infected themselves but they then also cannot pass this infection onto other people, where it may cause severe disease.

However, for herd immunity to work a large proportion of the population need to be vaccinated. It is achieved when 90 to 95 percent of any given population is vaccinated (specifically with the measles vaccine), according to the Oxford Vaccine Group.

Herd immunity is important, the group says, because it helps protect those who are unable to receive the vaccine for any number of reasons.

Jay R. Jordan covers breaking news in the Houston area. Read him on our breaking news site, Chron.com, and our subscriber site, HoustonChronicle.com | Follow him on Twitter at @JayRJordan | Email him at jay.jordan@chron.com | Text CHRON to 77453 to receive breaking news alerts by text message