Gavi launches vaccine programs for Ebola, meningitis, rabies, and hepatitis B

News brief

Gavi, the Vaccine Alliance, and its partners today announced that lower-income countries can now apply to four more vaccine programs, which cover Ebola for high-risk groups, rabies vaccine for postexposure prophylaxis, multivalent meningococcus, and hepatitis B. 

child vaccination
Doune Porter/GAVI Alliance/Flickr cc

The four vaccine programs were approved earlier by Gavi's board, but were put on hold because of either the COVID-19 pandemic, availability of suitable products, or appropriate policy recommendations.

Access for lower-income nations

In a statement, Gavi said the latest expansion of its vaccine portfolio fits with the group's goal of ensuring that lower-income countries have access to key vaccines as soon as possible. 

For the Ebola vaccine, Gavi will begin funding preventive doses in countries most at risk, targeting populations at greatest risk, including frontline health workers and outbreak responders. The meningitis vaccine in Gavi's program targets five serogroups, A, C, W, Y, and X, and has already been used to protect about 5 million people in outbreaks involving serogroups C and W in Niger and Nigeria. 

Gavi and its partners have been working since 2018 to prepare for the launch of a rabies postexposure prophylaxis vaccine program. The disease is a serious health problem in 150 countries, mostly in Africa and Asia and mostly in children ages 5 to 14 years old. The group has also been working on a hepatitis B birth dose program since 2018.

Rapid test for urinary tract infections wins Longitude Prize

News brief

The Longitude Prize on antimicrobial resistance (AMR) was awarded to Sysmex Astrego AB yesterday for the development of a rapid antimicrobial susceptibility test for urinary tract infections (UTIs).

The PA-100 AST System, developed at Sweden's Uppsala University, uses nanofluidic technology to detect bacteria in a urine sample in 15 minutes and identify the right antibiotic in as little as 45 minutes, and requires no specialized laboratory testing expertise. Sysmex Astrego was among more than 250 teams vying for the £8 million (US $10.2 million) prize, which aims to incentivize the development of transformative point-of-care tests that will improve antibiotic treatment decisions. 

"Winning the Longitude Prize is the first true and biggest recognition that what we have been doing all these years was for a very important global cause," Ozden Baltekin, PhD, Sysmex Astrego director of program management, said in a press release.

Sysmex Astrego launched the PA-100 AST System in Europe in 2023. The company says the prize will enable it to accelerate efforts to expand the global market for the test.

CARB-X to fund rapid test for chlamydia, gonorrhea

In other diagnostic news, CARB-X announced today that it will award Fuse Diagnostics up to $1 million to develop a rapid diagnostic test for chlamydia and gonorrhea.

The funding will help Fuse demonstrate proof-of-concept and feasibility of Apex CT/NG, a molecular, instrument-free diagnostic for the detection of Chlamydia trachomiti and Neisseria gonorrhoeae. The hope is that the low-cost test would be ideally suited for areas in low- and middle-income countries with limited access to secondary healthcare and centralized laboratory testing.

According to the World Health Organization, there were an estimated 129 million chlamydia and 82 million gonorrhea infections in 2020. If left untreated, they can cause pelvic inflammatory disease and infertility in women. 

"We need rapid diagnostics that allow healthcare workers to test and treat gonorrhea out of the gate, as inappropriate treatment has led to the point that only one effective antibiotic remains," Erin Duffy, PhD, chief of research and development at CARB-X (Combating Antibiotic-Resistant Bacteria Biopharmaceutical Accelerator), said in a press release.

Study details reduced Tamiflu susceptibility in H1N1 flu cases

News brief

A study yesterday in Emerging Infectious Diseases spotlights recent H1N1 flu cases with reduced susceptibility to oseltamivir (Tamiflu), the most common antiviral used to limit symptoms from seasonal flu. 

The reduction in susceptibility has been seen in viruses collected from five continents—with most cases in Europe—from May 20203 to February 2024. The viruses showed a 13-fold reduced inhibition by oseltamivir while retaining normal susceptibility to other antiviral drugs, the authors said. 

The detections were made as part of standard genetic sequencing of influenza viruses, and included 2,039 H1N1 viruses from the United States (1,274) and 38 other countries (765).

Most detections made in Europe 

The viruses that lost susceptibility to Tamiflu had acquired a novel combination of neuraminidase mutations, NA-I223V + S247N. Overall detection frequency of these two mutations was low (0.67%). Of 101 viruses with this double mutation, 67 were found in Europe. 

"The first dual mutant was collected from Canada in May 2023, and the latest were collected from 4 countries (France, the Netherlands, Spain, and the United Kingdom) during January–February 2024," the authors wrote. 

The Netherlands had the most detections (30), followed by France (24), Bangladesh (11), Oman (9), and the United Kingdom (9). Hong Kong had 4 detections, followed by Niger (3), Australia (2), Spain (2), and the United States (2). One dual mutant each was detected in Canada, Ethiopia, Maldives, Norway, and Sweden.

Our study highlights the need to closely monitor evolution of dual mutants .

"Our study highlights the need to closely monitor evolution of dual mutants because additional changes may further affect susceptibility to antiviral drugs or provide a competitive advantage over circulating wild-type viruses," the authors concluded. 

Low-cost, at-home antibody test can flag low immunity against COVID-19, researchers say

News brief
SARS-CoV-2 antibodies
ktsimage / iStock

An at-home antibody test can gauge users' immunity to COVID-19, alerting to the need for a vaccine booster dose, a University of North Carolina–led research team reports in Science Advances.

The investigators evaluated the performance of the low-cost lateral-flow antibody test in 168 healthcare workers with weak COVID-19 vaccine responses. They also measured SARS-CoV-2 neutralizing antibody and T-cell responses among all participants before and after a third vaccine dose.

By the end of 2022, more than 96% of Americans 16 years old or older had SARS-CoV-2 antibodies from infection or vaccination, the study authors wrote. "However, immunity against SARS-CoV-2 tends to wane over time and is typically less effective against evolving SARS-CoV-2 variants." 

Positive results don't necessarily show adequate immunity

A negative result on the test indicated low immunity, while a positive result didn't necessarily indicate sufficient immunity. Those who tested positive had higher antibody concentrations than those who tested negative. After wild-type SARS-CoV-2 booster vaccination, all participants gained systemic antibodies against evolving SARS-CoV-2 and related viruses.

Our research suggests that an antibody test taken at home will allow at-risk individuals to conveniently identify inadequate immunity to COVID-19 in a world in which population immunity is declining.

John Lafleur, MD, PhD

"Our research suggests that an antibody test taken at home will allow at-risk individuals to conveniently identify inadequate immunity to COVID-19 in a world in which population immunity is declining," coauthor John Lafleur, MD, PhD, of George Washington University (GWU), said in a GWU news release. "This can be important information for those who are considering booster vaccination, but question whether or not it is needed."

Booster uptake in the United States has been low despite its ability to reduce the risk of severe disease. "Even among 65 and older US residents, the bivalent booster uptake has been reported as under 41%, suggesting the need for new strategies to build confidence and promote the use of the SARS-CoV-2 vaccine," the authors wrote.

They noted difficulties interpreting negative results: "Redesigning the tests to specifically detect negative Ab [antibody] results with clear instructions for interpreting those results will prevent any positive results that could mislead people into believing they are completely protected against COVID-19."

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