Nationwide vaccine hesitancy continues to concern healthcare officials. Since the COVID-19 pandemic, there has been a rise in vaccine misinformation on social media.
In Indiana, the state Department of Health found vaccine rates for children 19 to 34 months peaked at more than 70% in 2020 but declined to 56.4% in 2023.
In Monroe County, full-series vaccination rates peaked at 83% in 2019, falling to 69% in 2023. Despite the drop, the county still ranks in the top 10 for most vaccinated counties in Indiana, placing third highest in 2019 and ninth highest in 2023.
Additionally, for the measles vaccine, 85.3% of eligible infants received the MMR1 vaccine in 2023, down from 91% in 2019.
Libby Richards, professor of public health at Purdue University, said the decrease in vaccination rates can be attributed to COVID-19.
She said during the pandemic, visits to primary care providers and pediatricians decreased significantly, which is where most vaccinations are administered.
Richards also said that inaccurate information is spread online through misconceptions about vaccines, such as myths that vaccines have chemicals or will give you the actual virus. However, the most difficult misinformation to combat comes from people that are highly trusted.
“If somebody's mom passed this information down and, like, you really believe your mom and she thinks she's the best mom ever,” she said. “That's going to be tricky to try to change somebody's mind.”
Richards said vaccination drives and mobile clinics can by increase vaccination rates by making vaccines more easily accessible.
“I think reducing any type of barrier to vaccine is going to help increase rates,” she said. “So sometimes accessibility is a barrier, and so if we bring vaccines to where folks are, that is one way to increase it.”
However, Richards said that increasing vaccination access alone can’t increase vaccination rates. She said a knowledge shift about vaccines is also needed.
The rise in vaccine hesitancy comes amid a surge in measles cases across the U.S., with 483 confirmed cases as of March 27.
In late February, a measles outbreak in Texas and New Mexico killed one person, the first measles-related death in the U.S. in a decade.
According to the Centers for Disease Control and Prevention, 95% of measles cases reported in 2025 were from individuals who are unvaccinated or their vaccination status is unknown.
John Christenson is the associate medical director of pediatric infection prevention at the Riley Hospital for Children in Indianapolis. He said the measles outbreak in the U.S. Southwest is the largest ongoing outbreak, but multiple other states and a few provinces in Canada have reported cases as well.
Measles fall under indirect contact infections, which means it can be spread without direct contact, making it much more dangerous.
Unlike COVID-19 or influenza, which have a reproduction rate of one to two people, measles is significantly more contagious, where one person could potentially infect 12-15 people.
“Measles is definitely — I would say right now circulating around the world is — perhaps the most contagious virus that you'll ever see,” he said.
Christenson said vaccinations are important for measles because humans are the only reservoir for the disease. This means measles can only be spread through humans, and there are no animals or environmental hosts unlike other infectious diseases.
The MMR (measles, mumps and rubella) vaccine is traditionally administered in two doses, with the first dose, MMR1, being given at 12-15 months old, and the second dose, MMR2, being given at 4 to 6 years old.
Lori Kelly, Monroe County Health Department health administrator, said in an email, Monroe County is working to increase vaccine access through mobile outreach clinics and increasing vaccine education.
The Indiana Department of Health and the Monroe County Health Department will host a mobile MMR vaccine clinic on from 1:30-5:30 p.m. March 31 at the southwest branch of the Monroe County Public Library.
In 2023, the CDC found 90.8% of Indiana kindergarteners were fully vaccinated with the MMR vaccine, down from 94.4% in 2019. The Office of Disease Prevention and Health Promotion’s Healthy People 2030 plan has a goal of 95% of kindergarteners vaccinated with the full MMR series, the target for herd immunity.
“When you look at the measles vaccine, children that have received at least two doses are 97% protected,” he said. “So, it's a very effective vaccine.”
Christenson said some side-effects from vaccines such as the MMR include rashes, mild fever and soreness, but there is no evidence vaccines cause harmful developmental problems, a misconception that is commonly circulated. Christenson also emphasized that no caregiver wants to put their children in harm, but misinformation about vaccines creates hesitancy.
“Parents want the best for their children,” he said. “There's no question that that's always the case. Obviously, parents are maybe concerned about the safety of vaccines, you know, the sad part is that there's a lot of misinformation out there and that misinformation comes from all kinds of different sources.”
Christenson said vaccine mandates for attending public schools and universities significantly reduced the spread of infectious diseases in the U.S.
Indiana has around a 3% annual rate of personal vaccine exemptions for kindergarteners, which are non-medical vaccine exemptions. This allows unvaccinated children to circumvent vaccine mandates for public schools and universities, and Christenson advocates for the removal of non-medical vaccine exemptions.
Nationwide, non-medical vaccine exemptions are increasing, jumping from 1.4% in 2011 to 3.1% in 2023.
One of the largest vaccine critics in the U.S., is Children’s Health Defense, founded by Robert F. Kennedy Jr., the current Health and Human Services secretary. Children’s Health Defense claims vaccines can be linked to an increase in chronic diseases, such as autism, as well as claiming development delays more likely in vaccinated people.
Richards said when government officials like Kennedy have mistrust toward vaccines, it increases public mistrust.
Recently, Kennedy announced the CDC is planning to launch additional studies on autism and measles, despite existing studies that vaccines are safe. Richards warns this will increase vaccine mistrust.
Christenson also said numerous studies have shown no correlation between autism and the MMR vaccine, and those funds to fund studies can be allocated to better public health causes.
Christenson said government policy directly impacts vaccination rates, and it is necessary for lawmakers to understand the importance of vaccines.
“We need to talk with our congressmen,” Christenson said, “we need to talk with our senators, we need to talk and send messages as individuals, all of us, to our different politicians and inform them about the importance of vaccinations and that they don't cut back on programs that provide them.”
