CDC Warns Of Measles Spread: MA Has Among Highest Vaccination Rates

MASSACHUSETTS — Federal health officials warned this week that measles cases are on the rise both domestically and globally, with 58 confirmed cases in 17 states, a tally that doesn't yet include Massachusetts.

The 58 cases reported as of March 14 are equal to all cases reported in 2023, the Centers for Disease Control and Prevention said in an advisory to health care providers. The agency said 93 percent of the measles cases were linked to international travel, and that destinations such as Austria, the Philippines, Romania and the United Kingdom are all experiencing measles outbreaks.

Other states reporting cases were Arizona, California, Florida, Georgia, Illinois, Indiana, Louisiana, Maryland, Michigan, Minnesota, Missouri, New Jersey, New York City, Ohio, Pennsylvania, Virginia and Washington.

Massachusetts was among the states that were part of a large nationwide measles outbreak in 2019. The CDC counted 1,249 cases that year, with two in Massachusetts. The outbreak was the largest in the U.S. up to that point dating back to 1992.

Most U.S. measles cases this year are among children around 1 year of age who have not yet had measles-mumps-rubella (MMR) vaccinations, the CDC said. The CDC typically recommends two doses of MMR vaccine, the first at age 12 to 15 months and the second at 4 to 6 years, or before starting school for the first time.

Massachusetts is among the states that require MMR vaccinations for anyone in kindergarten through 12th grade, plus some healthcare workers. Pockets of the country continue to have low vaccine coverage, leaving some areas at higher risk for outbreaks.

As of the beginning of the 2022-23 school year, 93.1 percent of incoming kindergarten students had received the necessary doses of MMR vaccine, according to CDC estimates. In Massachusetts, 96.5 percent of kindergarteners entering public school received their MMR shots, according to the estimates. In general, herd immunity happens when 95 percent of a given population has been vaccinated.

But vaccination rates can be much lower at religious and private schools — and some public schools — because state law allows exemptions for medical or religious reasons. Medical exemptions and religious exemptions accounted for about 1.4 percent of all missed immunizations (just over 900 total students) during the 2022-23 school year, according to the state Department of Public Health.

There were more than 150 kindergarten classes in the 2022-23 school year with sub-95 percent MMR vaccination rates. Classes at the Berkshire-Waldorf School in Great Barrington, Blessed Sacrament in Walpole, James Hennigan public in Boston, Benjamin Banneker Charter Public School in Cambridge, James Otis public Boston, Alma Del Mar Charter in New Bedford, Maurice Donahue public in Holyoke and Trinity Catholic Academy (lower campus) in Brockton all had MMR vaccine rates below 70 percent in the 2022-23 school year, according to state data.

The early symptoms of measles include a high fever, cough, runny nose, and pink eye, which can last for about two to four days before a rash appears. The incubation period for measles, from initial exposure to fever, is usually around 10 days. The rash typically starts about 14 days after the initial exposure.

The virus responsible for measles is transmitted through direct contact with infectious droplets or by airborne spread when an infected person breathes, coughs, or sneezes. It can remain infectious in the air and on surfaces for up to two hours after an infected person has left. Infected people are contagious four days before the rash starts through four days after.

Correction: An earlier version of this story incorrectly stated the MMR vaccination rate in Massachusetts. The story has been updated with the correct data.