This episode of This Week in Virology (TWiV 1217) covers critical science news, including the controversial appointment of Vinay Prasad to the FDA's SBER, the Gates Foundation's 20-year plan to disburse its funds, and a new executive order imposing restrictions on gain-of-function research. The scientific discussion centers on two papers: one from Cell that refines the timeline and geographic origins of bat viruses ancestral to SARS-CoV-1 and SARS-CoV-2, implicating recent circulation (1-6 years prior to human emergence) and wildlife trade in their spread; and another from Nature Communications detailing a promising single-dose, self-replicating RNA vaccine for Sudan virus, which, delivered via a LION nanocarrier, provided complete protection in a guinea pig model. The episode also features listener emails and diverse picks of the week.
TWiV 1217: SARS Origins, Sudan Vaccine, and Science in a Shifting Landscape
0:02:56 Multi-Pathogen Diagnostics: Discussion highlights the availability of comprehensive PCR panels (e.g., from BioFire) that can test for numerous respiratory pathogens simultaneously, moving beyond single-pathogen tests. This was prompted by an anecdote of a patient sequentially infected with COVID-19 and then Metapneumovirus.
0:06:25 Concerns over FDA SBER Leadership Change: The appointment of Vinay Prasad as the new SBER director at the FDA raises concerns among the hosts due to his "contrarian" views on COVID-19 measures and criticisms of the drug industry. They worry about potential negative impacts on vaccine approval standards and regulatory predictability.
0:11:56 Gates Foundation to Sunset by 2045: Bill Gates announced plans for the Gates Foundation to spend all its funds within the next 20 years. Key aspirations include preventing maternal/child deaths from preventable causes, eradicating deadly infectious diseases, and lifting millions from poverty.
0:16:20 Executive Order on Gain-of-Function Research: A new presidential executive order aims to restrict "dangerous gain-of-function research." The hosts critique its vague definitions, political motivations, and potential to hinder legitimate scientific inquiry, noting its implicit link to SARS-CoV-2 lab-leak theories.
0:25:01 SARS-CoV-1 & -2 Ancestral Origins (Paper 1): A Cell paper used phylogenetic analysis of non-recombinant viral genome regions to estimate that bat virus ancestors of SARS-CoV-1 and SARS-CoV-2 circulated 1-6 years before their emergence in humans. Their likely geographic origins were over 1000 km from emergence sites (Guangzhou/Wuhan).
0:45:04 Wildlife Trade Implicated in SARS Emergence (Paper 1): The study suggests that the ancestral viruses of SARS-CoV-1 and SARS-CoV-2 reached their human emergence locations too quickly for natural bat dispersal alone, implicating human-mediated transport of infected animals via the wildlife trade. This finding reinforces calls to address risks from such trade.
0:54:49 Novel Sudan Virus Vaccine Candidate (Paper 2): A Nature Communications paper details a self-replicating RNA (replicon RNA) vaccine against Sudan ebolavirus. This platform aims for single-dose efficacy, crucial for outbreak response where multi-dose regimens are challenging.
0:59:54 LION Delivery System Shows Promise (Paper 2): The Sudan virus replicon RNA vaccine utilized a LION (Localizing Cationic Nanocarrier) delivery system, where RNA is adsorbed to the surface of an oil-in-water emulsion, potentially reducing reactogenicity compared to LNPs. A single dose provided 100% protection against lethal Sudan virus challenge in guinea pigs.
1:15:27 Rabies Vaccination for Veterinarians Clarified: Listener emails from veterinarians confirm that rabies vaccination (currently a two-dose pre-exposure series in the US) and subsequent titer checks are standard and often mandatory for veterinary students and professionals in North America, correcting a previous discussion.
1:42:38 Unprecedented 2023 Summer Warmth: Vincent's pick of the week highlights a Nature study concluding that the Northern Hemisphere's summer of 2023 was the warmest in the past 2,000 years, exceeding natural climate variability significantly and underscoring the urgency of addressing anthropogenic climate change.