At a Glance
- US likely to lose measles elimination status soon
- Early vaccine delays cut MMR coverage
- CDC shifts hepatitis B timing to 2 months
- Why it matters: Delays increase risk of measles outbreaks
A new study published in JAMA Network Open shows that children who miss early vaccines are less likely to receive the first MMR dose on schedule, threatening the United States’ measles elimination status.
Early Vaccine Delays Cut MMR Coverage
The study examined 321,743 children with regular access to care and found that getting the recommended vaccines in the first four months is the strongest predictor that a child will receive the MMR vaccine between 12 and 15 months. On-time MMR rates fell from 79.9% in 2021 to 76.9% in 2024, with boys and rural children slightly less likely to be vaccinated.
- DTaP (diphtheria, tetanus, pertussis)
- Rotavirus
- Polio
- Pneumococcal
- Haemophilus influenzae type b (Hib)
- Hepatitis B
Changing Schedule Sparks Hesitancy
The CDC’s advisory panel recently advised that newborns wait until 2 months to receive the first hepatitis B shot, a move that has already raised concerns among parents. Other changes to the schedule are expected in 2026, further fueling uncertainty.
| Year | On-time MMR Rate |
|---|---|
| 2021 | 79.9% |
| 2024 | 76.9% |
The decline suggests that schedule changes can erode trust and create a cascade effect on other vaccines.
Impact on Public Health
With more than 2,000 measles cases reported in 2025, the disease is re-emerging in the United States. Experts warn that gaps in immunity, especially during the 6-to-12-month window before the first MMR dose, leave children vulnerable.
Nina Masters said:
> “It was a surprise for me to see how early this was happening. To see that the first visit, that 2-month visit, we’re already seeing a strong effect between parents who are delaying that vaccine and then not getting the MMR vaccine for their child, to me, just indicates that that hesitancy is happening really early.”
Angela Rasmussen said:
> “You’re going to be unprotected for a longer period of time while that delay is in place. There’s no evidence of any of these things.”
Dr Nathan Lo said:
> “If that first dose is delayed even further, say, two years, or what have you, then there’s an even bigger window for there to be gaps in susceptibility that put children at risk of measles, especially when measles is starting to circulate more in the United States.”
Dr Lee Harrison said:
> “Measles is sort of the canary in the coal mine, the smoke alarm. When you start to see declines in coverage rates, then you start to see outbreaks.”
- Early vaccine delays reduce MMR coverage
- CDC shifts hepatitis B timing may erode trust
- Measles cases rising, highlighting vulnerability
Key Takeaways
- Early vaccine delays cut MMR coverage, threatening measles elimination.
- CDC’s change to hepatitis B timing could fuel parental hesitancy.
- Rising measles cases underscore the need to maintain the strict vaccine schedule.
The findings underscore the urgency for parents, clinicians, and policymakers to address vaccine hesitancy early and maintain the rigorous schedule that protects children from measles and other preventable diseases.
