A new national analysis from Bader Law reveals a widening divide in how Americans approach vaccination, report adverse events, and respond to public health guidance. The study shows that vaccine behavior is no longer uniform across the country. Instead, it is shaped by political identity, geographic isolation, personal belief systems, and shifting confidence in medical institutions. These divisions have created a patchwork of risk that is now influencing disease outbreaks, exemption rates, and the reporting of vaccine side effects.
The data paints a picture of a country where vaccine decisions vary sharply from state to state, and where the consequences of those decisions are becoming increasingly visible.
COVID‑19 Vaccine Risks and Myocarditis Patterns
The study begins with an examination of myocarditis, a rare heart inflammation associated with both COVID‑19 infection and mRNA vaccination. Federal data shows that COVID‑19 has killed more than 2,000 children and teenagers, including 700 infants. At the same time, an FDA official has linked ten child deaths to COVID‑19 vaccination, citing myocarditis as a contributing factor.
Key findings include:
- Young males ages 12 to 30 face the highest myocarditis risk after vaccination.
- 81 percent of myocarditis patients recovered within three months.
- People infected with COVID‑19 were over seven times more likely to develop myocarditis than vaccinated individuals.
- 61 percent of myocarditis cases occurred in men.
- Only 1.07 percent of cases required hospitalization.
- Fatal myocarditis cases were extremely rare at 0.015 percent.
- Moderna’s vaccine showed the highest myocarditis rate among the vaccines studied.
- Studies from the United States and Mexico reported myocarditis rates nearly three times higher than those in Europe.
These findings highlight a central tension in the national conversation. While the risk of myocarditis after vaccination is low, the presence of any risk has fueled skepticism in some communities, especially when combined with conflicting expert opinions.
Confidence in Vaccines Is Uneven
The study cites a KFF poll showing that Americans remain confident in long‑established vaccines but express significantly less confidence in the COVID‑19 vaccine.
Confidence levels:
- Measles vaccine: 83 percent
- Pneumonia vaccine: 82 percent
- Shingles and flu vaccines: 74 percent
- COVID‑19 vaccine: 56 percent
Political identity plays a major role:
- 87 percent of Democrats express confidence in COVID‑19 vaccines
- 55 percent of independents
- 30 percent of Republicans
This divide has contributed to uneven vaccination uptake and rising nonmedical exemptions.
Nonmedical Exemptions Continue to Rise
One of the clearest indicators of shifting vaccine behavior is the rise in nonmedical exemptions among kindergarteners. During the 2024 to 2025 school year, 3.6 percent of kindergarteners received exemptions, up from 2.2 percent a decade earlier. Medical exemptions remain below 1 percent nationwide, meaning most exemptions stem from personal or religious beliefs.
Top States for Nonmedical Exemptions (2024 to 2025)
| State | Percent of Exempt Kindergarteners |
|---|---|
| Idaho | 15.1% |
| Utah | 10% |
| Oregon | 9.7% |
| Alaska | 9% |
| Arizona | 9% |
| Nevada | 6.7% |
| North Dakota | 6.7% |
| South Dakota | 6.7% |
| Michigan | 6.5% |
| Wisconsin | 6.3% |
ABC News attributes high exemption rates in rural states to limited access to medical providers and lingering concerns about COVID‑19 vaccines that have influenced attitudes toward other vaccines.
Declining Vaccination Coverage and the Measles Surge
The consequences of rising exemptions are already visible. During the 2024 to 2025 school year, national kindergarten vaccination coverage fell to:
- 92.1 percent for DTaP
- 92.5 percent for MMR
- 92.5 percent for polio
Additional findings:
- 286,000 kindergarteners lacked documentation of completed MMR vaccination.
- Exemptions increased in 36 states and the District of Columbia.
- 138,000 kindergarteners were exempt from one or more vaccines.
By December 16, 2025, the United States recorded 1,958 measles cases, the highest total in years.
Measles Case Breakdown (2025)
Age distribution:
- Under 5 years: 512 cases
- Ages 5 to 19: 808 cases
- Over 20: 625 cases
- Unknown: 13 cases
Vaccination status:
- Unvaccinated or unknown: 93 percent
- One MMR dose: 3 percent
- Two MMR doses: 4 percent
Hospitalizations:
- Total hospitalized: 222 people
- Under 5 years: 20 percent
- Ages 5 to 19: 6 percent
- Over 20: 11 percent
Measles Trends Over Time
| Year | Cases |
|---|---|
| 2025 | 1,958 |
| 2024 | 285 |
| 2023 | 59 |
| 2022 | 121 |
| 2021 | 49 |
States With the Most Measles Cases (2025)
| State | Cases |
|---|---|
| Texas | 803 |
| Arizona | 182 |
| South Carolina | 142 |
| Utah | 122 |
| New Mexico | 100 |
The Texas outbreak began in a Mennonite community before spreading to other under‑vaccinated areas, illustrating how quickly measles can spread when immunity levels fall.
States With the Fewest Cases (2025)
- Zero cases: Delaware, District of Columbia, Maine, Massachusetts, Mississippi, New Hampshire, North Carolina, West Virginia
- One case: Alabama, Connecticut
Political Identity and Adverse Event Reporting
The study also examines how political identity influences the reporting of vaccine side effects. A cross‑sectional analysis of 620,456 adverse event reports found that:
- A 10 percent increase in Republican voting correlated with a 5 percent increase in reported COVID‑19 vaccine adverse events.
- Severe adverse event reporting increased 25 percent under the same conditions.
This suggests that political identity affects not only vaccine uptake but also the likelihood of reporting adverse reactions.
Gender Differences in Adverse Events and Fatalities
Among 45,843 adverse events after one vaccine dose:
- 31,018 were female
- 14,688 were male
- 137 unconfirmed
Fatalities from 2020 to 2025 totaled 7,259, including:
- 4,348 male deaths
- 2,847 female deaths
Top States for Male Deaths
| State | Deaths |
|---|---|
| Kentucky | 418 |
| Texas | 294 |
| Michigan | 216 |
| Florida | 191 |
| California | 190 |
Top States for Female Deaths
| State | Deaths |
|---|---|
| Kentucky | 339 |
| Texas | 209 |
| California | 130 |
| Florida | 101 |
| Michigan | 97 |
Kentucky stands out with 757 total deaths, three times higher than expected based on population.
Adverse Event Reporting by State
Highest Number of Adverse Reports (First COVID‑19 Dose)
| State | Reports |
|---|---|
| California | 4,726 |
| Texas | 2,894 |
| Florida | 2,581 |
| Michigan | 2,540 |
| New York | 2,349 |
Lowest Number of Reports
| State | Reports |
|---|---|
| Wyoming | 82 |
| Vermont | 119 |
| District of Columbia | 134 |
| North Dakota | 135 |
| Delaware | 137 |
A Nation Divided in Vaccine Behavior
The study from Bader Law shows that the United States is experiencing a period of fragmentation in vaccine behavior. Confidence in vaccines varies widely, exemption rates are rising, and disease outbreaks are becoming more common in under‑vaccinated communities. At the same time, adverse event reporting is influenced by political identity, and gender differences in reported side effects remain significant.
The result is a public health landscape defined by uneven risk. Some states maintain high vaccination coverage and low disease incidence, while others face rising exemptions, higher adverse event reporting, and growing vulnerability to outbreaks. The data suggests that until vaccine confidence becomes more consistent across the country, these disparities will continue to shape national health outcomes.
