Butantan dengue vaccine estimated to be 81% effective against severe disease for at least 5 years

News brief

Vaccine in syringe — *rogerashford / iStock*

The single-dose dengue vaccine developed by Brazil’s Butantan Institute is 80.5% effective against hospitalization for the mosquito-borne disease for at least five years, per a phase 3 clinical trial published in Nature Medicine.

Led by Butantan Institute researchers, the double-blind, placebo-controlled trial estimated the safety and effectiveness of the live, attenuated, tetravalent (four-strain) Butantan-DV vaccine in participants aged two to 59 years. Participants were randomly assigned to receive the vaccine (10,259 people) or placebo (5,976) at 16 Brazilian research centers from 2016 to 2019.

The main goal was to evaluate the vaccine effectiveness (VE) against symptomatic dengue 28 days post-vaccination due to any dengue virus serotype (variant), regardless of serostatus (antibody presence or absence). Secondary endpoints were VE by serotype, by serostatus, and protection against severe dengue or dengue with warning signs (combined).

The Brazilian Health Regulatory Agency approved Butantan-DV in November 2025 for use in people aged 12 to 59 years.

“The spread of dengue has greatly increased worldwide over the past two decades,” the authors wrote. “Natural infection by one dengue virus (DENV) serotype allows homotypic protection [against the same strain] but subsequent heterotypic infection by another of the four DENV serotypes (DENV-1 through DENV-4) can result in severe disease.”

Individual protection, reduced viral circulation

Over five years, no vaccinated participants were hospitalized. VE against symptomatic dengue was 65.0%. VE was 77.1% in previously infected participants, 58.9% in dengue-naive participants, 73.0% against DENV-1, and 55.7% against DENV-2. Cases of DENV-3 and DENV-4 weren’t observed.

This vaccine is establishing itself as a very important tool in the fight against dengue in Brazil, with the potential to contribute to reducing the circulation of the virus, in addition to individual protection.

Fernanda Boulos, MD, PhD

VE against dengue with warning signs or severe dengue was 80.5% (95% confidence interval, 50.8% to 92.4%). The most common solicited systemic adverse event (AE) was headache (36.7% of vaccine recipients, 31.1% of placebo recipients).

In a press release, corresponding author Fernanda Boulos, MD, PhD, of Butantan Institute, said, “This vaccine is establishing itself as a very important tool in the fight against dengue in Brazil, with the potential to contribute to reducing the circulation of the virus, in addition to individual protection.”

WHO releases guidance for urgently needed new antibiotics

News brief

Chris Dall, MA

The World Health Organization (WHO) yesterday published blueprints to guide development of urgently needed new antibiotics for three types of bacterial infections.

The three new target product profiles (TPPs) focus on new antibiotics for:

Severe multidrug-resistant gram-negative infections caused by carbapenem-resistant Enterobacterales, Acinetobacter baumannii, and Pseudomonas aeruginosa
Severe antibiotic-resistant gram-positive infections in immune-suppressed and critically ill patients, with a focus on Enterococcus faecium
Community-acquired and health care-associated bacterial meningitis

Antibiotic-resistant bacteria in petri dish — TopMicrobialStock / iStock

The purpose of TPPs is to help accelerate the drug development process—and establish priorities for researchers, funders, and developers—by outlining the desired characteristics for new antibiotics. They describe the intended use, target populations, mechanism of action, and route of administrations, and define clear targets for quality, safety, efficacy, pharmacokinetics, access, and affordability.

“They are intended to facilitate the most expeditious development of novel antibiotics addressing the greatest and most urgent public health needs posed by antimicrobial resistance (AMR),” the WHO said.

Antibiotic development not keeping up with resistance

All three of the targeted infection types are currently treated with antibiotics that are becoming less effective as drug resistance rises, and there are few candidates in the antibiotic pipeline to provide new treatment options. WHO officials say the aim of the three new TPPs is to align antibacterial product development with the WHO’s bacterial priority pathogens list, prioritize infections that lead to high morbidity and mortality, and incentivize and de-risk antibiotic development.

“The scientific community has developed and approved new antibiotics in recent years. This is good, but unfortunately not sufficient to catch up with evolving drug-resistance bacteria, especially against those of greatest concern,” Yvan Hutin, MD, PhD, director of antimicrobial resistance at the WHO, said in a press release. "We need a reliable pipeline with new antibacterial agents that are innovative, affordable, accessible to all those who need them.”

Avian flu strikes more Indiana poultry facilities

News brief

Stephanie Soucheray, MA

Indiana continues to be a hotbed of avian flu activity, according to this week’s reports from the US Department of Agriculture (USDA) Animal and Plant Health Inspection Service (APHIS).

The state had eight outbreaks of highly pathogenic avian flu in the past week in three counties, Elkhart, Lagrange, and Jay. Jay County had the largest outbreak, involving 20,600 birds on a commercial turkey meat farm. Elkhart County had four separate outbreaks, three of which involved duck meat facilities.

Wisconsin reported two major outbreaks among egg-laying chickens on farms in Jefferson and Walworth counties, with more than 3 million birds affected.

14 million birds affected in past month

Also of note this week: another detection of avian flu at a live-bird market in Queens, New York, affecting 40 birds.

In the past 30 days, APHIS has confirmed 77 avian flu outbreaks that affected 41 commercial farms and 36 backyard flocks, with 13.98 million birds affected.

Wild-bird avian flu detections continue across the country, but have slowed down in the past week with only 29 noted by APHIS, including waterfowl in Kentucky and a bald eagle in Kansas.