Universal coronavirus vaccine mosaic on nanoparticles, toad venom depression therapy, medieval Winchester leprosy, and exoplanet 55 Cancri e atmosphere via JWST

Podcast at a glance

The Naked Scientists episode surveys a Cambridge vaccine mosaic approach that glues shared coronavirus coat regions onto nanoparticles to train the immune system, a modified Sonoran Desert toad venom line aimed at treating depression without hallucinogenic effects, evidence of leprosy transfer between humans and red squirrels in medieval Winchester, and the James Webb Space Telescope discovery of an atmosphere around rocky exoplanet 55 Cancri e.

Key insights

• Universal coronavirus vaccine strategy using mosaic proteins
• Toad venom derivatives seek antidepressant effects without hallucinogenic trips
• Leprosy cross-species transmission detected in medieval humans and squirrels
• Atmosphere detected around rocky exoplanet 55 Cancri e via secondary eclipse analysis

Introduction and scope

The Naked Scientists episode brings together several science stories from Cambridge and beyond. The central thread in the first segment is a vaccine technology from the University of Cambridge that uses a mosaic of viral proteins attached to a protein nanoparticle. This approach is designed to train the immune system to recognize parts shared across a range of coronaviruses, potentially offering protection against future viruses that might emerge in the same family. The discussion emphasizes the goal of a ready-to-use vaccine library that could be deployed in future pandemics, including the possibility of a universal flu vaccine, which remains a substantial challenge due to the diversity of influenza viruses.

Universal coronavirus vaccine mosaic

Participants explain that the basis is a protein nanoparticle that displays eight different coronavirus spike protein components. Rather than picking specific targets a priori, the strategy trains the immune system to focus on parts shared among related viruses. Outputs used to assess protection include antibody binding measured by ELISA, pseudovirus neutralization assays, and live-virus neutralization tests. The results in animals are promising, with neutralizing responses against included and related, but not identical, viruses. A notable point is the ability to generate strong responses even when the vaccine lacks the exact coronavirus stimulus, indicating a robust cross-protective potential. The long-term vision described is to have a panel of pre-validated vaccines that can be deployed rapidly in a future outbreak.

Experts also discuss the challenges of applying similar strategies to influenza, highlighting the virus’s enormous diversity and the need for vaccines that not only bind but neutralize effectively, a higher bar for flu vaccines than for some coronaviruses.

From bench to bedside: outputs and future steps

Three main outputs are used to gauge potential protection: 1) verifying that antibodies bind the viral proteins (ELISA), 2) testing the ability of antibodies to block infection with a modified, non-dangerous virus carrying a coronavirus spike (pseudovirus neutralization), and 3) evaluating whether antibodies protect against the actual virus in cell culture. The team reports strong protection in these assays, including instances where a Covid-related virus is not present in the vaccine.

Looking ahead, the scientists envision a future where vaccine libraries validated for safety and efficacy could be stockpiled and rapidly deployed during pandemics. The dialogue also touches on the broader challenge in flu vaccines that require not just binding but true neutralization of a highly variable target.

Toad venom and depression therapy

The episode then moves to a Nature study on a modified version of the Sonoran Desert toad venom. Researchers aim to separate the antidepressant effects from the powerful hallucinogenic properties of 5-MeO-DMT. Using computer-assisted receptor modeling and in silico pharmacology, they identify variants that selectively engage pathways linked to mood improvement while avoiding the 5-HT2A receptor signature responsible for trip effects. Early tests in mice show selective activity at the 5-HT1A receptor, which is associated with stress-related circuits and some antidepressant mechanisms. The next steps involve validating these compounds in humans and addressing past clinical challenges faced by earlier compounds that resembled 5-MeO-DMT derivatives and had significant side effects.

Experts caution that translating this to clinical practice will require careful safety assessments, given the controversial nature of psychedelics in medicine and the historical difficulties with psychedelic compounds in trials.

Leprosy transmission between humans and squirrels

The podcast then explores archaeology and biology research from Winchester, where medieval leprosy (Mycobacterium leprae) DNA has been detected in human teeth and in the fur-trade waste pits containing squirrel remains. The scientists analyze dental pulp to recover pathogen DNA and compare bacterial sequences between ancient humans and squirrels to reconstruct transmission networks. The modern squirrel populations show differences in their bacterial strains, suggesting that leprosy moved between species in the past and may have persisted in animal reservoirs. The researchers highlight a potential circular dynamic where humans and local wildlife can exchange infection repeatedly, a pattern also seen in other pathogens such as certain bird flu viruses and coronaviruses. The study emphasizes the need to consider animal hosts in eradication strategies for diseases historically viewed as human-only pathogens.

55 Cancri e atmosphere and exoplanet science

The program then covers astronomy news from the James Webb Space Telescope. 55 Cancri e, a rocky, highly irradiated “super-Earth” around a nearby star, is found to have a substantial atmosphere. Using a secondary eclipse technique, astronomers compare light before and after the planet passes behind its star, effectively isolating the planet’s emission. The best-fitting atmospheric models point to a mix of carbon dioxide and carbon monoxide, implying a dense atmosphere on a hot, molten surface. The discussion covers the implications for exoplanet demographics and the eta-Earth parameter, the estimated fraction of stars hosting Earth-like planets. The takeaway is that atmospheres around rocky planets may be more common than previously thought, which has exciting implications for the search for life beyond Earth.

Question of the week: plastic aging and brittleness

Rounding out the program, a question about why new plastic is flexible while old plastic becomes brittle leads to a detailed chemistry discussion. Polymers are long chains that can slide past one another; factors such as branching, cross-linking, and plasticizers determine flexibility. Environmental aging, including heat, light, and oxygen exposure, can break polymer chains or promote cross-linking, and plasticizers can diffuse out, all contributing to brittleness or changes in mechanical properties over time. The conversation also touches on a notable Barbie-doll preservation issue, illustrating real-world aging of PVC products and the loss of plasticizers. The segment ends by pointing listeners to further resources and inviting more questions for future episodes.

Closing remarks

The show signs off with the host, highlighting the Cambridge Institute of Continuing Education as the venue and noting support from partner institutions, before inviting listeners to engage with the forum and contribute questions.