Measles vaccination rates for young children may be as low as 71% in younger children, well below the threshold needed for herd immunity.

Both formulations of the so-called MMR vaccine contain weakened live forms of the measles virus. The vaccine does occasionally cause mild side effects, such as swelling at the injection site, fever or a mild rash; there is no valid evidence that the MMR vaccine causes autism.

Texas and New Mexico have seen an increase in vaccinations for measles since its outbreak in the states. Since late January, Texas has reported 327 measles cases, including 40 hospitalizations. One unvaccinated school-aged child has died because of measles,