FROM THE EDITOR

World Immunization Week - world agencies reflect on the gains and challenges of vaccine initiatives

World Immunization Week, usually in the last week of April, has just been celebrated. This time around there were many concerns clouding the achievements over the decades. Misinformation, population growth, humanitarian crises and funding cuts threaten immunisation efforts. Progress made through the decades is endangered. The World Health Organization (WHO), United Nations Children's Fund (UNICEF) and the Vaccine Alliance (Gavi) warned during the week that millions of children, adolescents and adults are vulnerable and at risk.^[1] They called for sustained investments in immunisation efforts in the face of funding cuts, which are either already in place or imminent.

The WHO reports that outbreaks of vaccine-preventable diseases such as measles, meningitis and yellow fever are on the increase globally. In addition, diseases that have been contained and prevented from progressing for long and sustained periods, such as diphtheria, are at risk of resurfacing. This also applies to diseases that have virtually disappeared in many countries. Vaccines protect against >30 life-threatening diseases.^[2]

Over the last 50 years, essential vaccines have saved 154 million lives. This translates to six lives a minute, every day, for five decades. During this time, there has been a 40% improvement in infant survival, and 'more children now live to see their first birthday and beyond than at any other time in human history'.^[2] The measles vaccine alone accounts for 60% of those lives saved.

Substantial progress has also been made in other areas of immunisation. Africa has the highest cervical cancer burden in the world. In a concerted global effort to eliminate cervical cancer, the human papillomavirus (HPV) vaccine coverage nearly doubled between 2020 and 2023, from 21% to 40%, in the African Region. Increases in global coverage of pneumococcal conjugate vaccines, mostly in the South-East Asia Region but also being introduced in parallel in Chad and Somalia, where there is a high disease burden, are just some of the other advances made in immunisation. In addition, remarkable progress has been made in the context of malaria vaccines in Africa, where there has been subnational introduction of these vaccines in nearly 20 countries, paving the way for saving half a million additional lives by 2035 as the vaccines are taken up by more countries, and vaccination programmes are rapidly expanded.^[1]

Despite these many achievements, concerns abound. There have been several reports on the alarming resurgence of measles. Since 2021, the number of cases has been increasing year on year. This follows the pattern of reductions in immunisation coverage that was seen during and since the COVID-19 pandemic in several population groups. It is estimated that there were 10.3 million measles cases in 2023, a 20% increase compared with 2022. The WHO, UNICEF and Gavi warn that this upward trend is likely to continue into 2025, with outbreaks intensifying around the world. The past 12 months have evidenced the highest number observed in any 12-month period since 2019, with 138 countries reporting measles cases, and 61 experiencing large or disruptive outbreaks.^[1]

In Africa, meningitis cases also rose sharply in 2024, and this pattern continues into 2025. There were >5 500 suspected cases and nearly 300 deaths reported in 22 countries in January, February and March alone this year. In 2024, there were approximately 26 000 cases and almost 1 400 deaths across 24 countries. Africa has also seen a climb in yellow fever cases. In 2024, there were 124 confirmed cases reported in 12 countries, despite the dramatic decline in the disease over the last 10 years. The latter was made possible because of global vaccine stockpiles and use of yellow fever vaccine in routine immunisation programmes. Since January this year, yellow fever outbreaks have been confirmed in the WHO Region of the Americas, where there have thus far been 131 cases in 4 countries.^[1]

These outbreaks started before and continue into the era of global funding cuts. A recent WHO rapid stock-take^[3] in 108 WHO countries (mostly low- and lower-middle-income countries) has revealed that nearly 50% of those countries are facing moderate to severe disruptions to vaccination campaigns, routine immunisation and access to supplies as a result of reduced donor funding. Disease surveillance, including for vaccine-preventable diseases, has also been impacted.^[1,3] Concurrently, there has been an increase in the number of children missing routine vaccinations in recent years, despite countries making efforts to catch up with children missed during the pandemic. Alarmingly, ~14.5 million children missed all of their routine vaccine doses in 2023. This displays a rising trend from 12.9 million in 2019 and 13.9 million in 2022. More than 50% of these children live in countries where there is conflict, fragility, or instability, and poor or no access to basic health services.^[1] The global funding crisis exacerbates the situation even further.^[1]

As we celebrate the great achievements that progress in vaccines has made, it is also prudent for us to reflect on how to address the dangers these gains are now facing. We must remember that vaccines are one of the highest-impact interventions. Governments need to invest in ensuring that countries catch up where they lag behind. The public, parents and the private sector have roles to play too. The public sector could consider investing in vaccines as part of its corporate social investment initiatives. This is where shared responsibilities among these stakeholders could go a long way to save lives and prevent diseases.

Ames Dhai
Acting Editor
Ames.Dhai@wits.ac.za

References

1. World Health Organization. Increases in vaccine-preventable disease outbreaks threaten years of progress, warn WHO, UNICEF, Gavi. Geneva: WHO, 2024. https://www.who.int/news/item/24-04-2025-increases-in-vaccine-preventable-disease-outbreaks-threaten-years-of-progress--warn-who-unicef--gavi (accessed 25 April 2025).         [ Links ]

2. World Health Organization. World Immunization Week 2025. Geneva: WHO, 2025. https://www.who.int/campaigns/world-immunization-week/2025 (accessed 25 April 2025).         [ Links ]

3. World Health Organization. The impact of suspensions and reductions in health official development assistance on health systems. https://www.who.int/publications/m/item/the-impact-of-suspensions-and-reductions-in-health-official-development-assistance-on-health-systems (accessed 25 April 2025).         [ Links ]