Tag: diphtheria

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Fridge-free Tetanus-diphtheria Vaccine Shows Promise of Reaching Millions Worldwide

On By ModernMedia
Nurse and participant in the vaccine trial.

The world-first trial of a fridge-free tetanus-diphtheria vaccine has produced encouraging results that could improve access worldwide to crucial treatments, while reducing carbon emissions.

Around half of vaccines are wasted globally each year, according to the World Health Organization. Millions of doses are lost because of temperature changes during storage and transport. Fridge-free vaccines have the potential to transform vaccine delivery by reducing this dependence on refrigeration. This would improve access in more isolated communities and cut the environmental impact by reducing vast amounts of energy that lead to emissions.

This phase I study, led by the University of Southampton and University Hospital Southampton NHS Foundation Trust, found the vaccine was well tolerated, with no vaccine-related serious adverse events. Results are published in The Lancet group’s eClinicalMedicine.

Saul Faust , Professor of Paediatric Immunology and Infectious Diseases at the University of Southampton and Director of the NIHR Clinical Research Facility in Southampton, who led the study, said: “Keeping vaccines cold from the factory to the patient is one of the biggest challenges facing immunisation programmes worldwide. Our study suggests that this vaccine can remain safe and effective without refrigeration.

“If larger studies confirm these findings, this technology could help transform the way vaccines are stored and delivered around the world.”

The trial

The trial took place in the National Institute for Health and Care Research (NIHR) Clinical Research Facility at University Hospital Southampton and was delivered through the NIHR Biomedical Research Centre: Southampton . The reformulated vaccine, known as SPVX02, was developed by UK-based biotech company Stablepharma using its StablevaX technology.

The research shows that SPVX02 can be stored at temperatures of up to 30°C for at least two years without losing its effectiveness. Scientists are now investigating whether it can remain stable for as long as four years. Researchers have also demonstrated that the vaccine remains stable, and fully potent, after three cycles of extreme temperature fluctuation from -20°C to +40°C.

The randomised trial, which also involved the Medicines Evaluation Unit (MEU) in Manchester, enrolled 60 healthy adults. By 28 days after vaccination, all participants receiving SPVX02 achieved protective antibody levels against both tetanus and diphtheria, demonstrating immune responses comparable to licensed vaccines.

Next steps

The eClinicalMedicine publication follows the launch of a Phase 2b trial that will further assess the vaccine in a larger group of participants. Stablepharma’s technology platform, StablevaX, can be applied to vaccines, small molecules, peptides and biologics. They are currently working with a partner to thermostabilise small molecule oncology and anti-infective products, in addition to other vaccines.

Özgür Tuncer, Stablepharma CEO and Executive Director, said: “This peer reviewed validation represents a pivotal moment for our StablevaX platform and the future of thermostable vaccines. These findings strengthen the scientific and global health case for a new generation of fridge free vaccines, particularly in regions where cold chain limitations hinder equitable access.”

Health and Social Care Minister Diana Johnson said: “This pioneering research demonstrates how British innovation is helping to tackle some of the biggest challenges in global healthcare, and providing life-saving breakthroughs for use around the world.

“Right now, people are dying of preventable diseases all over the world, not due to a lack of vaccines, but a lack of refrigeration. Fridge-free vaccines have the potential to be a game-changer for global health, especially for people in remote communities, or regions affected by conflict.

“Backed by NIHR’s world-leading research, this breakthrough shows once again how our investment in science and life sciences is driving better health outcomes, while supporting economic growth and reinforcing the UK’s position at the forefront of medical innovation.”

Stablepharma’s SPVX02 vaccine has been developed with support from Innovate UK, part of UK Research and Innovation (UKRI). It is a reformulated version of the WHO-prequalified Tetadif tetanus-diphtheria vaccine. Scientists from the UK Health Security Agency (UKHSA) provided specialist laboratory testing.

Stablepharma expects to complete the clinical development programme for SPVX02 by 2027.

Source: University of Southampton

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Diphtheria Resurfacing as a Threat As it Evolves Antibiotic Resistance

On By ModernMedia

Diphtheria is resurfacing as a threat worldwide as it evolves antibiotic resistance and could escape vaccine containment, scientists warn.

Diphtheria cases in recent years have doubled what they were in previous decades, to 16 651 cases in 2018. Although babies are vaccinated against it in high-income countries, there is less coverage in middle- and low-income countries.

Diphtheria is mainly caused by Corynebacterium diphtheriae, spread by coughs and sneezes or close contact with the infected. Usually, the bacteria cause acute infections, driven by the diphtheria toxin—the main target of the vaccine. However, non-toxigenic C. diphtheria can also cause disease.

A team of researchers from the UK and India used genomics to map infections, including a subset from India, where more than half of the globally reported cases occurred in 2018.

Analysing the genomes of 61 bacteria isolated from patients and combining these with 441 publicly available genomes, the researchers were then able to understand how they spread. They also used this information to assess the presence of antimicrobial resistance (AMR) genes and assess toxin variation.

The researchers found clusters to genetically-similar bacteria isolated from different continents, most commonly Asia and Europe. This indicates that C. diphtheriae has been travelling with humans as they spread across the planet.

The diphtheria toxin ch is encoded by the tox gene, for which the researchers found 18 different variations, of which several had the potential to change the structure of the toxin.

Professor Gordon Dougan from the Cambridge Institute of Therapeutic Immunology and Infectious Disease (CITIID) said: “The diphtheria vaccine is designed to neutralise the toxin, so any genetic variants that change the toxin’s structure could have an impact on how effective the vaccine is. While our data doesn’t suggest the currently used vaccine will be ineffective, the fact that we are seeing an ever-increasing diversity of tox variants suggests that the vaccine, and treatments that target the toxin, need to be appraised on a regular basis.”

First author Robert Will, a PhD student at CITIID, said: “The C. diphtheriae genome is complex and incredibly diverse. It’s acquiring resistance to antibiotics that are not even clinically used in the treatment of diphtheria. There must be other factors at play, such as asymptomatic infection and exposure to a plethora of antibiotics meant for treating other diseases.”

Erythromycin and penicillin are commonly recommended to treat early-stage diphtheria, although there are other classes capable of it. Variants resistant to six of these classes in isolates from the 2010s were identified by the team.

Study leader Dr Ankur Mutreja from CITIID, said: “It’s more important than ever that we understand how diphtheria is evolving and spreading. Genome sequencing gives us a powerful tool for observing this in real time, allowing public health agencies to take action before it’s too late.
“We mustn’t take our eye off the ball with diphtheria, otherwise we risk it becoming a major global threat again, potentially in a modified, better adapted, form.”

Source: Medical Xpress

Journal information: Will, RC et al. Spatiotemporal persistence of multiple, diverse clades and toxins of Corynebacterium diphtheria. Nat Comms; 8 Mar 2021; DOI: 10.1038/s41467-021-21870-5