Merck Collaborator Instituto Butantan Announces Results from Its Phase 3 Vaccine Candidate Trial for the Prevention of Dengue Disease


December 16, 2022 7:00 am ET

RAHWAY, N.J., Dec. 16, 2022 – At Merck (NYSE: MRK), known as MSD outside of the United States and Canada, we are highly encouraged by the tremendous progress scientists and clinicians at the Instituto Butantan have made in developing their single dose dengue disease vaccine candidate. We are working with Instituto Butantan to conduct a detailed analysis of these results in order to determine next steps for our own dengue vaccine candidate (V181).

Instituto Butantan’s announcement represents an important clinical research milestone for the global health community. Both Merck and Instituto Butantan’s investigational vaccines are derived from materials licensed from the U.S. National Institutes of Health (NIH) and both institutions are evaluating formulations analogous to the NIH TV003 formulation. Under the collaboration agreement announced in December 2018, Merck and Instituto Butantan are sharing clinical data and other learnings from their respective dengue vaccine development programs.

This collaboration is an example of how Merck is engaging the global public health community to develop vaccines for important diseases primarily affecting tropical and subtropical regions of the world.

About dengue

Dengue is one of the fastest growing mosquito-borne diseases that affects not just the health but often the economic stability of people across the globe. It is a leading cause of serious and sometimes debilitating illness in tropical and subtropical countries.1 With approximately half of the world’s population, or four billion people, at risk for dengue disease, dengue is a critical public health challenge. Globally, 400 million dengue infections occur annually, according to the WHO2, with 50-100 million infections being symptomatic.3,4 While the majority of infections are uncomplicated, serious illness caused by dengue can be severe and lead to death5 (~500,000 cases per year are severe enough to require hospitalization and ~2.5% of severely affected individuals may die6). Mild dengue fever is characterized by a high fever, rash, and muscle and joint pain. A severe form of dengue fever, (dengue hemorrhagic fever) can cause severe bleeding, a sudden drop in blood pressure and death.7

About Merck

At Merck, known as MSD outside of the United States and Canada, we are unified around our purpose: We use the power of leading-edge science to save and improve lives around the world. For more than 130 years, we have brought hope to humanity through the development of important medicines and vaccines. We aspire to be the premier research-intensive biopharmaceutical company in the world – and today, we are at the forefront of research to deliver innovative health solutions that advance the prevention and treatment of diseases in people and animals. We foster a diverse and inclusive global workforce and operate responsibly every day to enable a safe, sustainable and healthy future for all people and communities. For more information, visit and connect with us on TwitterFacebookInstagramYouTube and LinkedIn.

Forward-Looking Statement of Merck & Co., Inc., Rahway, N.J., USA

This news release of Merck & Co., Inc., Rahway, N.J., USA (the “company”) includes “forward-looking statements” within the meaning of the safe harbor provisions of the U.S. Private Securities Litigation Reform Act of 1995. These statements are based upon the current beliefs and expectations of the company’s management and are subject to significant risks and uncertainties. There can be no guarantees with respect to pipeline candidates that the candidates will receive the necessary regulatory approvals or that they will prove to be commercially successful. If underlying assumptions prove inaccurate or risks or uncertainties materialize, actual results may differ materially from those set forth in the forward-looking statements.

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1WHO | Dengue and severe dengue. Published online 2022. Accessed November 28, 2022.

2WHO | Dengue and severe dengue. Published online 2022. Accessed November 28, 2022.

3Russell KL, Rupp RE, Morales-Ramirez JO, et al. A phase I randomized, double-blind, placebo-controlled study to evaluate the safety, tolerability, and immunogenicity of a live-attenuated quadrivalent dengue vaccine in flavivirus-naïve and flavivirus-experienced healthy adults. Hum Vaccin Immunother. Published online 2022:1-12. doi:10.1080/21645515.2022.2046960

4Messina JP, Brady OJ, Golding N, et al. The current and future global distribution and population at risk of dengue. Nat Microbiol. 2019;4(9):1508-1515. doi:10.1038/s41564-019-0476-8

5WHO | Dengue and severe dengue. Published online 2022. Accessed November 28, 2022.

6WHO | Dengue and severe dengue. Published online 2021. Accessed June 6, 2022.

7Mayo Clinic | Dengue fever. Published online 2022. Accessed November 28, 2022.,pressure%20(shock)%20and%20death.

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