The health landscape in the United States faces several challenges as we approach 2026, particularly concerning infectious diseases. Experts express growing concern over declining vaccination rates and the potential resurgence of diseases that were once under control. Here, we highlight the top five infectious diseases to monitor closely in 2026.
Top 5 Infectious Diseases to Monitor in 2026
1. Influenza
- Current flu season showing significant activity.
- CDC reports around 15 million cases, 180,000 hospitalizations, and over 7,400 deaths so far, including 17 pediatric fatalities.
- Flu vaccination coverage among children is less than 50%, the lowest in six years.
Public health experts anticipate the flu season this year could mirror last year’s severity, which saw 280 deaths among children. The CDC’s recent shift in flu vaccination guidelines has raised concerns among pediatricians about creating confusion among parents.
2. Measles
In 2025, the U.S. reported over 2,000 measles cases, marking the highest totals in decades. Measles, once eliminated in 2000, highlights the dangers of insufficient vaccination and public reluctance toward established vaccines. Experts stress the importance of the measles vaccine, which has saved countless lives over the years.
3. Polio
- Polio is a serious concern as vaccination rates decline.
- The disease remains prevalent in countries like Pakistan and Afghanistan.
The U.S. successfully eliminated polio through vaccination efforts, but skepticism about vaccines poses risks. Experts fear a return of polio if unvaccinated populations remain susceptible.
4. Disease X
Disease X is not a currently known virus but a placeholder for any future epidemic or pandemic potential. Health experts emphasize the importance of preparing for such unknown threats. The experience from past pandemics calls for increased vigilance and proactive measures in public health policy.
5. Bird Flu
- Currently, there is a low public health risk from bird flu.
- Close monitoring is ongoing due to outbreaks in wild birds and sporadic human cases.
While the transmission of bird flu between humans has not been documented, the wide range of affected species raises concerns. A total of over 70 human cases and two deaths have been recorded since 2024, prompting continued vigilance from health authorities.
As we look ahead to 2026, understanding these infectious diseases is vital. The interplay of vaccination rates, public perception, and health policies will play a crucial role in safeguarding the population’s health. Awareness and proactive measures are required to mitigate the risks of these potential outbreaks.
