Columbia University researchers say low vaccination rates along with “measles parties” fueled the outbreak that spread in 2019.
NEW YORK — As far as viral diseases go, pretty much everything has fallen by the wayside to COVID-19, and for good reason. However, a new study from Columbia University warns that New York City may have a major measles outbreak on its hands in the future.
Researchers investigated NYC’s recent measles outbreak in 2018-19, which was the United States’ largest outbreak of that kind in decades. They determined that delayed vaccinations among young children, in combination with lots of contact between infected kids, was largely to blame for the NYC outbreak last year. The study’s authors also pointed to so-called “measles parties,” or get-togethers among unvaccinated NYC children and their families.
Fast forward to today, and 2020 measles vaccinations have plummeted in the wake of COVID-19. In total, measles vaccinations among children are down 63%. That number balloons to 91% among everyone over the age of two over the past few weeks.
The stage is set for a big measles outbreak once social distancing guidelines are relaxed, researchers fear.
“At the moment, chances of an immediate measles outbreak in the City remain low thanks to the recent vaccination campaigns and current social distancing practice. But as the number of unvaccinated children increases and contact resumes, there would be a much greater risk of disease spread. ” says study author Wan Yang, PhD, assistant professor of epidemiology at Columbia University Mailman School of Public Health, in a release.
“Social distancing is needed to protect the population from COVID-19 while researchers work to develop a vaccine,” adds Yang. “Thankfully, for many other life-threatening infections such as measles, mumps, and rubella, we already have vaccinations to protect children from those diseases. It’s crucial that parents work with their doctors to make sure their children are vaccinated timely.”
Lessons Learned From 2019 Measles Outbreak
To analyze the 2018-19 NYC measles outbreak, Yang created a computer model that simulated measles infections within the NYC Orthodox Jewish community between October 2018 and July 2019 using data on confirmed local cases. It was estimated that about 25% of young children between the ages of one and four were susceptible to measles at that time, due to lack of vaccination. But, that fact alone wasn’t enough to account for that outbreak’s high rate of infection, suggesting to the study’s authors that “measles parties” played a prominent role in the outbreak as well.
To contain and stop the outbreak, the NYC Department of Health and Mental Hygiene tried to vaccinate as many people as possible and ordered mandatory vaccinations for everyone living, working, or attending school in the hardest hit zip codes. Those efforts resulted in over 32,000 people under the age of 19 being vaccinated by fall 2019. Around that time, the measles outbreak finally subsided.
According to Yang’s calculations, if NYC hadn’t taken those measures, 6,500-8,100 people could have been infected with measles, instead of the 649 confirmed cases. Most of those cases would have been among young children (one to four years old).
“These findings demonstrate the rippling effects of vaccine hesitancy to all susceptible age groups, particularly to infants too young to receive their first dose of MMR vaccine,” Yang says. “Administration of the first dose of the routine MMR vaccine earlier than the current guideline of 1 year may be needed to protect infants if high levels of vaccine hesitancy persist.”
The study is published in Science Advances.