As Vaccine Rates Drop, Infectious Disease Experts Say Outbreaks Will Become More Common

By Brendan Scanland

WASHINGTON, D.C. — As of Thursday, more than 480 cases of measles have been reported across the country. 

These recent outbreaks are responsible for more than three-dozen hospitalizations, one death reported in Texas and potentially another, which is still under investigation, in New Mexico. 

Measles is a highly contagious respiratory illness, one that can cause serious health risks, especially to unvaccinated individuals. 

“Because they have no protection against measles,” said Dr. Tina Tan, President of the Infectious Diseases Society of America. 

Dr. Tan has been studying infectious diseases for over 30 years. She’s a professor of pediatrics at the Northwestern University Feinberg School of Medicine and an attending physician in pediatric infectious diseases at Ann & Robert H. Lurie Children’s Hospital of Chicago. 

Dr. Tan says measles is one of the most transmissible and contagious viruses. 

“It only takes a very small amount of it to cause an infection, and it has airborne spread. Individuals that cough, that sneeze, that even breathe, who are infected with measles can actually transmit the measles virus in their respiratory droplets,” said Dr. Tan. 

The measles virus was common in the 1950s and 1960s. The introduction of the Measles vaccine in 1963 and then the Measles, Mumps and Rubella (MMR) vaccine shortly thereafter, kept the virus at bay until outbreaks in 1989 among vaccinated children. Those outbreaks prompted medical professionals to recommend a second dose of the MMR vaccine. 

Fast forward to 2025, the virus is reemerging again, but for a different reason. 

“We have seen declines in the MMR vaccination rates and there has been a significant increase in vaccine hesitancy and anti-vaccine sentiments,” said Dr. Tan. 

According to the CDC, when more than 95% of people in a community are vaccinated, most people are protected through community immunity, or herd immunity. However, vaccination coverage among U.S. kindergartners has decreased from 95.2% during the 2019–2020 school year to 92.7% in the 2023–2024 school year, leaving approximately 280,000 kindergartners at risk during the 2023–2024 school year. 

“The problem is, if you continue to let these vaccination rates drop, we’re going to see more measles transmission in the community,” said Dr. Tan. “If we cannot get vaccination rates up to protect more individuals, you’re going to continue to see these measles outbreaks occur.” 

“Vaccines not only protect individual children from measles, but also contribute to community immunity, protecting those who are unable to be vaccinated due to medical reasons,” said Health and Human Services Secretary Robert F. Kennedy Jr. in an op-ed earlier this month. “The measles outbreak in Texas is a call to action for all of us to reaffirm our commitment to public health. By working together parents, healthcare providers, community leaders, and government officials, we can prevent future outbreaks and protect the health of our nation. Under my leadership, HHS is and will always be committed to radical transparency to regain the public’s trust in its health agencies.” 

The recent outbreaks come as the top vaccine regulator at the FDA was reportedly forced out of his position Friday. In his letter of resignation, Dr. Peter Marks said his boss, RFK Jr., “wishes subservient confirmation of his misinformation and lies.” 

In a statement, an HHS spokesperson said, “If Peter Marks does not want to get behind restoring science to its golden standard and promoting radical transparency, then he has no place at FDA under the strong leadership of Secretary Kennedy.” 

Dr. Tan believes the message coming from the nation’s leaders needs to be clear and amplified. 

“The message that’s coming out right now is not encouraging vaccinations and really shows kind of a misunderstanding of how infectious diseases work,” said Dr. Tan. 

According to the CDC, as of March 27 a total of 483 confirmed measles cases were reported in 19 states including Michigan, New York and Pennsylvania. Of the total cases, 97% were unvaccinated or had an unknown vaccination status. Most cases have been reported in the southwest region of the country. As of Friday, Texas reported 400 cases, New Mexico had 44 and Oklahoma with at least nine cases.