The Democratic Republic of the Congo (DRC) is no stranger to mpox, an infection that is spread via close contact with symptoms including rash, fever and swollen lymph nodes. First discovered in 1958, the monkeypox virus responsible for the infection has caused thousands of cases in the African nation every year since 2005 and led to a global outbreak in 2022.
This year, a new type of mpox called clade Ib has contributed to an upsurge in the DRC and neighbouring countries, with almost 28,000 confirmed or suspected mpox cases and over 700 deaths reported in 15 African nations since January. In response, the World Health Organization (WHO) declared the outbreak a public health emergency of international concern in August and called for help in fighting the outbreak.
This month, the WHO granted prequalification approval to Bavarian Nordic’s U.S.-approved smallpox and mpox vaccine Jynneos to accelerate its progress to the front lines of the ongoing emergency in Africa and beyond. The organization is preparing to screen other vaccine candidates for the same process, including the smallpox vaccine LC-16 by KM Biologics and ACAM2000, another smallpox vaccine developed by Emergent BioSolutions. With donated doses coming in and supply agreements ongoing, the DRC is now expecting to roll out a vaccination campaign at the start of October, according to Reuters.
Obstacles to rolling out mpox vaccines
However, even with these vaccines in the pipeline, it will be a difficult task to carry out mpox vaccinations in the DRC.
“There are logistical challenges, political uncertainties, and a landscape of civil discord and ethnic violence,” said Kelly McKee, chief medical officer of the U.S. company Geovax, which is developing an mpox vaccine. “There is also the availability of the vaccine and the approvals that everybody needs to navigate to get the vaccine to the people that really need it.”
Another issue is the cost. While Bavarian Nordic doesn’t discuss its pricing publicly, the price of Jynneos – the most well known vaccine for mpox – is likely to be around $100 per dose, McKee said. For the DRC and other low-income nations, vaccinating a significant proportion of its 110 million-strong population at such prices is a daunting prospect.
A way to overcome the economic barrier is to implement a ring vaccination strategy, where vaccinations are limited only to those that are close contacts of confirmed mpox cases. The approach was successfully used in controlling smallpox and Ebola, but often requires rapid vaccination with a single dose. Therefore, it is unclear if Jynneos vaccinations, which require two doses weeks apart, could work in this situation, McKee explained.
A representative at Bavarian Nordic told BioPharma Reporter that the price of Jynneos is determined by many factors, importantly volume and commitment. Additionally, the company recently presented real-world effectiveness data for one and two doses respectively. However, two doses are the current recommendation and it is too early to speculate on the actual strategy being deployed in the different regions, the representative said.
While the one-dose ACAM2000 could be an option for a ring vaccination strategy, this older-generation vaccine carries the risk of serious adverse effects including myopericarditis and cardiomyopathy. For this reason, taking that route “requires that public health and policymakers in the DRC have the conviction that controlling mpox provides sufficient benefit to offset the risks of using ACAM2000,” especially in populations containing people with a suppressed immune system, said Seth Lederman, co-founder, CEO and chairman of Tonix Pharmaceuticals, which is developing its own mpox vaccine candidate.
More effective vaccination strategies
Geovax and Tonix are part of a group of companies gunning to produce more vaccine options for mpox. For example, Geovax’s preclinical-stage candidate is based on the same type of weakened virus as Jynneos and could compete to lower prices, McKee said. Meanwhile, another preclinical-stage candidate by Tonix is based on a weakened form of the horsepox virus and is designed to require just a single dose to protect against mpox.
Another way to smooth the process is to refine the supply chain. “One of the real shortcomings has been the fact that these vaccines are manufactured in the West and have to be exported to Sub-Saharan Africa,” McKee explained.
This can be tackled by bringing manufacturing close to the action, as the mRNA vaccine giant Moderna aimed when it drew up plans for an mRNA production facility in Kenya before hitting the pause button this year. However, there are efforts to strengthen the local vaccine manufacturing muscle in Africa with the establishment of the African Vaccine Manufacturing Accelerator (AVMA) last year.
In a broader sense, there is also encouraging progress in other disease control strategies, such as the diagnostics front. The WHO has helped the DRC to scale up mpox testing in the country this year with dramatic improvements in testing rates.
“There's a lot of R&D efforts ongoing to boost the diagnostic capabilities in Africa. During the Ebola outbreak, diagnostics rapidly emerged on the fly,” said McKee. “That's a model that probably will be replicated for the mpox situation as well.”