Diphtheria Could Re-emerge-WHO Warns

The World Health Organisation has warned that diphtheria, an acute and highly contagious bacterial disease that usually affects the mucous membranes of the nose and throat, which has since been defeated in many countries, risks re-emerging.

In a statement shared during the World Immunisation Week, which ends on Thursday, the organisation expressed fears that this disease and others, which have long been held at bay or virtually disappeared, could come back as immunisation efforts face challenges of misinformation, population growth, humanitarian crises, and funding cuts.

Already, the organisation reports, outbreaks of diseases such as measles, meningitis and yellow fever are rising globally.

“Vaccines have saved more than 150 million lives over the past five decades,” said WHO Director-General, Dr Tedros Adhanom Ghebreyesus. “Funding cuts to global health have put these hard-won gains in jeopardy. Outbreaks of vaccine-preventable diseases are increasing around the world, putting lives at risk and exposing countries to increased costs in treating diseases and responding to outbreaks. Countries with limited resources must invest in the highest-impact interventions – and that includes vaccines.”

Measles is making an especially dangerous comeback. The number of cases has been increasing year on year since 2021, tracking the reductions in immunisation coverage that occurred during and since the COVID-19 pandemic in many communities. Measles cases reached an estimated 10.3 million in 2023, a 20% increase compared to 2022.

The global health body, together with other UN agencies, warns that this upward trend is likely to continue into 2024 and 2025, as outbreaks have intensified around the world. In the past 12 months, 138 countries have reported measles cases, with 61 experiencing large or disruptive outbreaks — the highest number observed in any 12 months since 2019.

According to figures published by the WHO, meningitis cases in Africa also rose sharply in 2024, and the upward trend has continued into 2025. In the first three months of this year alone, more than 5500 suspected cases and nearly 300 deaths were reported in 22 countries. This follows approximately 26,000 cases and almost 1400 deaths across 24 countries last year.

When it comes to yellow fever, cases in the African region are also climbing, with 124 confirmed cases reported in 12 countries in 2024. This comes after dramatic declines in the disease over the past decade, which experts attribute to global vaccine stockpiles and the use of yellow fever vaccine in routine immunisation programmes.

Now, in the WHO Region of the Americas, yellow fever outbreaks have been confirmed since the beginning of this year, with a total of 131 cases in 4 countries.

These outbreaks come amidst global funding cuts. A recent WHO rapid stock take with 108 country offices of WHO—mostly in low- and lower-middle-income countries—shows that nearly half of those countries are facing moderate to severe disruptions to vaccination campaigns, routine immunisation, and access to supplies due to reduced donor funding. Disease surveillance, including for vaccine-preventable diseases, is also impacted in more than half of the countries surveyed.

At the same time, the number of children missing routine vaccinations has been increasing in recent years, even as countries make efforts to catch up on children missed during the pandemic. In 2023, an estimated 14.5 million children missed all of their routine vaccine doses—up from 13.9 million in 2022 and 12.9 million in 2019. Over half of these children live in countries facing conflict, fragility, or instability, where access to basic health services is often disrupted.

UNICEF Executive Director Catherine Russell says the global funding crisis is severely limiting their ability to vaccinate over 15 million vulnerable children in fragile and conflict-affected countries against measles.

According to her, immunisation services, disease surveillance, and the outbreak response in nearly 50 countries are already being disrupted, with setbacks at a similar level seen during COVID-19.

With such a grim picture, experts call upon parents and politicians to strengthen support for immunisation. The agencies, for instance, emphasise the need for sustained investment in vaccines and immunisation programmes and urge countries to honour their commitments to the Immunisation Agenda 2030, which puts countries at the forefront of ensuring immunisation targets are met. 

“Increasing outbreaks of highly infectious diseases are a concern for the whole world. The good news is we can fight back, and Gavi’s next strategic period has a clear plan to bolster our defences by expanding investments in global vaccine stockpiles and rolling out targeted preventive vaccination in countries most impacted by meningitis, yellow fever and measles,” said Dr Sania Nishtar, CEO of Gavi, the Vaccine Alliance in a statement. “These vital activities, however, will be at risk if Gavi is not fully funded for the next five years…”