On Wednesday, North Texas confirmed its first case of measles in Rockwall County. Health officials have indicated that this incident likely has no ties to the ongoing measles outbreak affecting West Texas, which tragically resulted in the death of an unvaccinated child in Lubbock, as noted in an official statement.

To effectively prevent measles, the measles, mumps, and rubella (MMR) vaccine is essential. Dr. Zachary Most, an assistant professor of pediatrics at UT Southwestern Medical Center and an expert in pediatric infectious diseases, emphasized the importance of this immunization.

In the United States, children receive the MMR vaccine in two doses. The initial dose is administered between 12 and 15 months of age and is 93% effective at preventing measles. The efficacy increases to 97% following the second dose, which is given between the ages of four and six.

Children under one year old do not receive the first dose of the MMR vaccine because they often retain some immunity from their vaccinated mothers. This passive immunity is transmitted through antibodies during pregnancy, as explained by Dr. Most.

Moreover, the MMR vaccination consists of live but weakened strains of the measles, mumps, and rubella viruses. The maternal antibodies can hinder the effectiveness of the vaccine in infants, reducing their immune response, according to Dr. Most.

“Live virus vaccines tend to be less effective in children under one year old,” Dr. Most noted. “Maternal antibodies may block the vaccine from eliciting the desired response.”

However, there are rare cases where infants might be eligible for the vaccine earlier than one year.

“Research shows it is safe to administer the MMR vaccine to children as young as six months,” Dr. Most mentioned. “Babies aged six to eleven months can receive the vaccine if they will travel to areas with endemic measles or if an outbreak is ongoing.”

The Texas Department of State Health Services has started recommending early vaccination for infants in Gaines County, located southwest of Lubbock. However, it hasn’t yet confirmed if similar guidance will be issued for Rockwall County or neighboring regions in North Texas.

Common symptoms of measles include fever, cough, runny nose, red eyes, and a distinctive rash. Typically, the rash begins on the scalp, then spreads to the face and body, as described by Dr. Most. Symptoms usually manifest one to two weeks after exposure to the virus, whether through contact with an infected person or via airborne droplets.

“In cases of measles, most children will experience a brief period of illness lasting two to four days with fever, cough, and congestion, followed by the emergence of a rash,” Dr. Most explained. “During this phase, affected children often appear quite unwell and face risks for complications, including dehydration, ear infections, and, in severe instances, pneumonia.”

Though measles was once a prevalent childhood illness in the U.S., it was declared eliminated in 2000 due to effective vaccination campaigns. Unfortunately, the nation has seen a rise in measles cases as childhood vaccination rates have begun to decline in recent years.

Dr. Most reiterated that immunizing children against measles remains the most effective safeguard, as long as they are old enough for vaccination, and it is vital that adults in their surroundings are also vaccinated.

Miriam Fauzia is a science reporting fellow at The Dallas Morning News, supported by the University of Texas at Dallas. Editorial decisions are made independently by the News.