The world is presently witnessing the resurgence of the monkeypox virus, reigniting global attention on infectious diseases beyond the COVID-19 pandemic. The spread of the virus mimics that of the SARS-CoV-2 outbreak on several fronts, characterised by affecting a broader range of populations than previously seen, and posing new challenges for public health systems.

With the virus evolving and spreading, although less spontaneously, the situation calls for enhanced vaccine development efforts in parallel. This article explores how the 2024 monkeypox outbreak is influencing the future of vaccines and how the global community is responding. 

The 2024 monkeypox outbreak: a new wave of challenges

Monkeypox (mpox) is a zoonotic virus endemic to the regions of West and Central Africa, where the virus has been found historically. Prior to 2022, disease outbreaks were sporadic in non-endemic areas, such as the UK, where cases were typically linked to travel or else direct contact with infected individuals from endemic countries. Between 2018 and 2021, for example, the number of mpox cases reported totalled only seven, with all cases tied to imported infections and with no sustained community transmission.¹

However, 2024 has witnessed a dramatic transition in the resurgence and extent of disease spread. The African Union alone has reported over 20,000 mpox cases across 13 countries, with the Democratic Republic of Congo (DRC) most affected, accounting for more than 19,000 cases and 575 deaths. Children under the age of 15 years comprise a sizable proportion of cases and fatalities, exacerbated by poor healthcare access and concurrent disease outbreaks.

Citing this important development, on 12 August 2024, the Africa Centres for Disease Control and Prevention declared a public health emergency. In the regions highlighted above the virus was, and still remains, a substantial public health threat.¹

On the other hand, non-endemic regions like the UK witnessed relatively fewer instances of illnesses in this wave; as of 31 July, the UK reported 286 cases. Although the risk of widespread transmission is small, a matter of significant concern is the increasing number of imported cases. This has raised public health concerns and prompted the European Centre for Disease Prevention and Control (ECDC) to elevate the risk level of clade I, a variant of the virus, for the general population.^1,2

The importance of vaccine development in managing monkeypox

Just as vaccine development campaigns were used as a means to control the spread of COVID-19, the same is true for containing a mpox outbreak. For bringing viral transmission to a halt, vaccines serve as a critical tool in breaking chains of spread and preventing further outbreaks. The revival of monkeypox in 2024 reiterates the importance of rapid and adaptive vaccine development in the face of a rising humanitarian crisis.

The Ebola outbreak in 2014 offered valuable lessons. This crisis not only lasted for two years, resulting in 11,000 casualties, but also presented an opportunity to develop and roll out a vaccine. Despite the discovery of a vaccine that demonstrated efficacy, deployment was delayed due to the prolonged duration of the epidemic.³

COVID-19 on the contrary was a different ball game altogether in that the entire research and development process—from the sequencing of the SARS-CoV-2 virus to the interim analyses of vaccine efficacy trials—was completed in under 300 days. Several factors contributed to this rapid response, driven by global collaboration, emergency use authorisations, and advances in mRNA vaccine technology.³

Monkeypox should derive important lessons from outbreaks in Ebola and COVID-19, concentrating efforts in the context of vaccine development. Given the evolving nature of the virus, a timely vaccine can be the distinguishing factor between containing an outbreak and allowing it to escalate. With new technologies, such as mRNA, there is potential to develop vaccines for monkeypox at pace and with broader immunity.

Vaccine development challenges in previous outbreaks

The following table provides a comparison of the key challenges faced across past disease outbreaks.^3,4

The current eligible vaccines for the mpox outbreak in 2024 may not provide optimal protection against emerging strains of the virus as genetic mutations have been observed. In addition, many endemic regions in Africa are vulnerable to the challenges associated with the uneven distribution of vaccines.

Historically, these regions have received medical interventions later than wealthier nations due to lack of local manufacturing. Weak healthcare infrastructure, limited cold-chain logistics, and financial dependence on global donors, further contribute to inadequacies in distribution.

Collaborative efforts to solve vaccine challenges

Global health organisations have played a pivotal role in addressing these challenges. In the fight against Ebola, organisations like the World Health Organization (WHO), the Coalition for Epidemic Preparedness Innovations (CEPI), and GAVI, the Vaccine Alliance, collaborated with pharmaceutical companies to expedite vaccine research and distribution.

With COVID-19, governments around the world provided emergency use authorisations (EUAs), allowing vaccines to be administered before completing all phases of clinical trials. Funding from organisations such as CEPI helped accelerate research into mRNA technology, which now holds promise for monkeypox vaccines.⁵

In the case of monkeypox, these organisations have again stepped in to facilitate vaccine development and distribution. The WHO and Africa CDC have been instrumental in tracking viral spread and coordinating response efforts.⁶ Meanwhile, pharmaceutical companies are racing to develop new vaccines that address the challenges posed by emerging monkeypox variants.

Current status of monkeypox vaccine development

In response to the 2024 outbreak, several technological advancements in vaccine development are being explored to enhance the effectiveness and availability of monkeypox vaccines. Genomic surveillance has played a key role, allowing scientists to track viral mutations and adapt vaccines accordingly. mRNA vaccine platforms, which were proven effective during COVID-19, are being studied for their potential to offer rapid and scalable responses to monkeypox outbreaks.⁷

Public-private partnerships have also accelerated the production of vaccines, with organisations like CEPI, WHO, cross-country donations, and pharmaceutical companies working together to ensure that new vaccines can be delivered quickly and equitably.^8,9,10 The timeline of events since the beginning of the outbreak this year is represented below. 

This timeline visually depicts the major international collaborations, initiatives, and key responses to infectious disease outbreaks.

How to solve current challenges

To address the current challenges in vaccine distribution, efforts should focus on increasing immunisation rates, especially among high-risk populations. Continuous surveillance is essential to identify areas with low vaccination coverage and guide outreach efforts. This will ensure resources are directed where they are needed most, particularly in vulnerable communities.

Targeted outreach programmes, such as health fairs and public service announcements, can raise awareness about monkeypox virus and the benefits of vaccination. These initiatives should emphasise confidentiality and avoid stagmatising high-risk individuals.

Public perception and vaccine hesitancy have also emerged as obstacles in non-endemic regions. Misinformation during the COVID-19 pandemic has led to increased skepticism around new vaccines, including those for monkeypox. Addressing this hesitancy will require targeted public health campaigns and clear communication about the safety and efficacy of vaccines.

Summary

The 2024 monkeypox outbreak has highlighted the urgent need for innovation in vaccine development and distribution. Drawing on lessons from past outbreaks, such as Ebola and COVID-19, global health organisations, governments, and pharmaceutical companies have made significant strides in developing more effective vaccines. However, challenges remain in ensuring equitable access, addressing public hesitancy, and adapting vaccines to emerging virus strains.

Sustained investment in vaccine research and development, coupled with strengthened global collaboration, will be essential in managing future monkeypox outbreaks and other emerging infectious diseases. By building on the progress made in recent years, the global health community can better prepare to respond swiftly and effectively to the next public health crisis.