- Diseases like whooping cough and measles are resurging globally after years of decline
- Japan saw a sharp pertussis surge in 2025, reflecting a worldwide increase since 2021
- Pandemic disruptions, vaccine hesitancy, waning immunity, and inequities drive disease comeback
Diseases once thought to be under control are making an alarming comeback across the world. From whooping cough (pertussis) to measles, public health experts are reporting a steady rise in cases, often in regions that had previously achieved strong immunisation coverage. A recent analysis, examining Japan's sharp pertussis surge in 2025, underscores a broader global trend: vaccine-preventable diseases are resurging, sometimes years after being suppressed. What's worrying is that this resurgence is not limited to one country.
Data from global health agencies show similar patterns in the United States, parts of Asia, and Europe, where outbreaks of measles and pertussis have increased significantly post-pandemic. The reasons are complex, ranging from disruptions to routine vaccination during Covid-19, to growing vaccine hesitancy and waning immunity over time.
These diseases are not just statistics. They can cause severe illness, long-term complications, and even death, particularly among children and vulnerable populations. The re-emergence of such infections raises an urgent question: are we losing ground in the fight against preventable diseases? Here's a science-backed look at what's driving this global comeback.
Whooping Cough: A Global Surge
Whooping cough, caused by the bacterium Bordetella pertussis, is a highly contagious respiratory disease often referred to as the "100-day cough" due to its prolonged symptoms. Japan witnessed one of the most striking surges in 2025. Surveillance data showed that reported cases in just the first half of the year were already several times higher than the total cases recorded in 2024.This reflects a broader global pattern, with the World Health Organization (WHO) noting a rising trend in pertussis cases across multiple regions since 2021. In the United States, cases increased sharply in 2024 and remained elevated in 2025 compared to pre-pandemic levels, according to the Centers for Disease Control and Prevention.
Experts say pertussis tends to follow cyclical outbreaks every few years, but the current spike is amplified by declining vaccination rates and reduced immunity in older populations.
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Measles: The Most Contagious Threat
If pertussis is concerning, measles is even more alarming. Measles is among the most infectious diseases known, capable of spreading rapidly in under-immunised populations. The WHO has reported a sharp increase in measles cases across East Asia and the Pacific in 2025, with countries like Vietnam, Mongolia, and the Philippines seeing thousands of infections. Globally, measles often acts as an early warning signal of falling vaccination coverage. Even small gaps in immunisation can trigger outbreaks, as the virus spreads quickly among unvaccinated individuals.
Why Are These Diseases Coming Back?
- Pandemic Disruptions: During COVID-19, routine vaccination programmes were severely disrupted. Millions of children missed essential immunisations, creating immunity gaps that are now surfacing as outbreaks.
- Vaccine Hesitancy: Misinformation and declining trust in vaccines have contributed to lower uptake in several countries. Even small declines can weaken herd immunity, allowing diseases to spread.
- Waning Immunity: Immunity from some vaccines, including pertussis, decreases over time. Without booster doses, adolescents and adults can become susceptible again, and unknowingly transmit infections.
- Global Inequities: Access to vaccines remains uneven. Low- and middle-income countries often face supply and distribution challenges, leaving large populations unprotected.
- Pathogen Evolution: Some studies suggest that pathogens like Bordetella pertussis may be evolving, potentially reducing vaccine effectiveness over time.
Other Diseases Re-Emerging
Beyond measles and pertussis, experts warn of a broader resurgence of vaccine-preventable diseases, including:
- Diphtheria
- Polio
- Rubella
- Meningococcal disease
Why This Matters For India
India has made significant progress in immunisation through programmes like Mission Indradhanush. However, experts warn that even temporary drops in vaccine coverage, such as those seen during the pandemic, can increase outbreak risks. Given India's large population and regional disparities in healthcare access, maintaining high vaccination coverage is critical to preventing similar resurgences.
What Can Be Done?
Health organisations emphasise several key steps:
- Strengthening routine immunisation programmes
- Catch-up vaccination campaigns for missed doses
- Public awareness to counter misinformation
- Monitoring outbreaks through surveillance systems
- Ensuring booster doses where needed
The resurgence of diseases like whooping cough and measles is a stark reminder that progress in public health is fragile. While vaccines have dramatically reduced illness and death over the past decades, gaps in coverage, whether due to disruptions, hesitancy, or access issues, can quickly reverse these gains. The recent surge in Japan and rising cases globally highlight the urgent need to rebuild and strengthen immunisation systems. Preventing the comeback of these diseases will depend not just on medical advancements, but on sustained public trust, policy support, and equitable access to vaccines.
Disclaimer: This content, including advice, provides generic information only. It is in no way a substitute for a qualified medical opinion. Always consult a specialist or your own doctor for more information. NDTV does not claim responsibility for this information.
