Measles outbreak in Ohio affects partially vaccinated children, babies too young to be vaccinated

The measles outbreak in Ohio continues to grow, affecting a total of 63 children to date. The number now includes at least three children partially vaccinated against the highly contagious virus and 14 children who are usually too young to be vaccinated.

The measles, mumps and rubella (MMR) vaccine is a two-dose vaccine, with the first dose recommended between 12 and 15 months of age and the second between 4 and 6 years of age. According to the Centers for Disease Control and Prevention, it is estimated that only one dose of MMR 93 percent effective against measles. Two doses are 97 percent effective. People who get their two doses according to the recommended schedule are considered protected for life.

It is not clear whether the three partially vaccinated children were too young to be eligible for a second dose or contracted measles soon after receiving the first dose, potentially before full protection had developed. Health officials in the affected areas of Ohio are promoting vaccinations, which may have prompted some parents to freshen up their eligible children amid heightened awareness. The affected areas in Ohio include at least two counties: Franklin County, which includes Columbus, and Ross County to the south.

Most cases are in completely unvaccinated children who are in the age range acceptable for at least one dose. Out of a total of 63 cases, 49 are between the ages of 1 and 17, and the majority (29) are between the ages of 1 and 2, according to dashboard set up by the Columbus Health Department. At the time of this reporting, the dashboard was last updated on December 8th. Out of a total of 63 cases, 60 were unvaccinated and 46 were aged 1 year or older.

Twenty-five of the 63 cases required hospitalization. In addition to being potentially life-threatening in young children, measles is also suppresses immune reactions weeks to months after infection, leaving children with increased susceptibility to other dangerous infections.

The outbreak, which began in in early November among unvaccinated children with no travel history to explain exposure, is thought to be linked to four travel-related cases reported earlier this year in Ohio.

Measles is considered eliminated in the US, because it has not spread continuously in the country since at least 2000, although it is occasionally introduced into the country through travel exposure. Declining vaccination rates amid dangerous anti-vaccine misinformation and pandemic-related health care disruptions now threaten the country’s status. The USA almost lost elimination status in 2019 in the midst of a protracted epidemic.

At a press conference last week, Columbus Public Health Commissioner Mysheika Roberts said at least 25 percent of 2-year-olds in the area are unvaccinated. She added that the health department is now working closely with the CDC and that the outbreak is expected to last several months.