Bavarian Nordic Launches Mpox Vaccine Trials for Pregnant Women and Infants in DRC

Bavarian Nordic, a leading biotechnology company, has commenced two significant Phase III clinical trials to evaluate the safety and immunogenicity of its mpox vaccine, Jynneos, in vulnerable populations, specifically pregnant and breastfeeding women, as well as infants under the age of two. These trials are being conducted in the Democratic Republic of Congo (DRC), the epicenter of the ongoing mpox outbreak, which has raised serious concerns about the health risks faced by these groups.

The first of these studies (NCT06844487) aims to recruit 344 infants aged between four months and two years, while the second trial (NCT06844500) will involve 359 pregnant and breastfeeding women. This initiative is part of the broader PregInPoxVac project, which is led by the University of Antwerp and the University of Kinshasa, with support from various partners including ACE Research in Kenya and the Penta Foundation in Italy. The project is funded by the European Union Global Health EDCTP3 program and the Coalition for Epidemic Preparedness Innovations (CEPI), alongside Bavarian Nordic.

Bavarian Nordic’s CEO, Paul Chaplin, emphasized the importance of these trials, stating, "Through partnerships, we have made significant advances by expanding access to our mpox vaccine for children and adolescents. These new studies will fill the gap by providing important data about the use of MVA-BN in infants and pregnant women, which could help support a label expansion for MVA-BN to include the most vulnerable populations."

The Jynneos vaccine, which is a non-replicating vaccine initially developed for smallpox, has shown efficacy against mpox and is currently approved in several regions, including the United States, European Union, Switzerland, Singapore, and the United Kingdom, where it is marketed as Imvanex.

The urgency of these trials is underscored by the ongoing mpox outbreak in the DRC. Recent reports indicate rising cases of mpox, particularly affecting infants and pregnant women, who are at a heightened risk of severe disease. The World Health Organization (WHO) has recognized the need for targeted vaccination strategies in these demographics, citing the vulnerability of such populations in outbreak scenarios.

As part of its commitment to global health, Bavarian Nordic previously pledged to deliver 2.5 million doses of the Jynneos vaccine to Africa through a collaboration with UNICEF, which included support from the Global Alliance for Vaccines and Immunization (GAVI). However, recent changes in U.S. funding priorities—specifically the announcement by U.S. Health Secretary Robert F. Kennedy, Jr. that the United States would cease financial support for GAVI—may impact future vaccine distribution efforts.

Bavarian Nordic's shares saw a 7% increase following the company’s Q1 financial announcement, driven by strong vaccine sales. Additionally, the company recently secured $160 million from the sale of a priority review voucher, although the buyer remains undisclosed.

In summary, the initiation of these clinical trials represents a critical step in addressing the health crisis posed by mpox in the DRC, particularly for its most vulnerable populations. The outcomes of these studies could pave the way for expanded use of the Jynneos vaccine, ensuring better protection for pregnant women and infants in regions affected by this outbreak. As global health dynamics continue to evolve, the successful execution of these trials will be pivotal in shaping future public health responses to mpox and similar infectious diseases.