This episode of This Week in Virology (TWIV 1218, recorded May 14, 2025) features Vincent Racaniello and Daniel Griffin discussing current topics in infectious diseases. The hosts express concern over the termination of a federal advisory committee on healthcare infection control, linking it to perceived attacks on science and public health funding. Updates on global outbreaks include rising Empox cases in Sierra Leone, avian influenza virus infections in felines as a potential zoonotic risk, and widespread measles outbreaks in the US, Canada, and Mexico, highlighting issues of vaccine misinformation and low coverage, particularly discussing unvaccinated populations and quarantine measures. The discussion covers the severity of the past flu season, noting high pediatric mortality rates primarily among unvaccinated children, and reviews studies on a potential pediatric flu treatment (Baloxavir) and the positive impact of new prevention products (maternal vaccine, Nirsevimab) on reducing infant RSV hospitalizations. COVID-19 updates include low wastewater levels, confirmation of wastewater surveillance as a predictor of clinical cases, strong scientific evidence supporting a zoonotic origin for SARS-CoV-2 (contrasting with lab leak theories), the increased risk of early pregnancy loss following COVID-19 infection, and the development of a promising combined Flu/COVID mRNA vaccine (mRNA 1083) which may face licensing challenges. Finally, they discuss the effectiveness of Remdesivir for hospitalized COVID-19 patients versus its high cost, and updates on long COVID, noting associations with excess weight and the identification of objective biomarkers. The episode concludes with listener questions covering various public health and medical topics, including vaccine adverse events and advocacy for science funding.
TWIV 1218: Clinical Update with Daniel Griffin
0:48 Concerns about Science Funding & HICPAC Termination: The hosts discuss the Trump administration's termination of the Healthcare Infection Control Practices Advisory Committee (HICPAC), an evidence-based federal advisory group established in 1991, criticizing it as a detrimental cut to public health infrastructure likely driven by political or budgetary reasons.
5:40 Empox (Monkeypox) in Sierra Leone: An update on the outbreak in Sierra Leone, noting a surge with around 100 new cases daily, driven by the global clade 2B strain. It's highlighted that a significant proportion (32%) of cases are female and most (93%) are HIV negative, differing from earlier outbreak demographics.
7:18 Bird Flu (AIV) in Felines: Discussion of a systematic review showing over 600 reported avian influenza infections in cats (domestic and wild felids) globally over two decades, including over 300 deaths. Cats are identified as a potential pathway for zoonotic spillover to humans, emphasizing the need for increased surveillance.
10:29 Widespread Measles Outbreaks: Updates on ongoing measles outbreaks in the US (exceeding 1,000 cases nationally by early May, including 717 in Texas and spread to Dallas), Canada (over 1,500 cases by late April), and Mexico (an outbreak centered in a Menonite community in Chihuahua with over 900 cases and 1 death).
11:00 Unvaccinated Quarantined in North Dakota: In response to a local measles outbreak, officials in Williams County, North Dakota, quarantined 188 unvaccinated school children for 21 days, enforcing a state law.
11:35 Misinformation and Distrust Hinder Vaccination: The hosts stress that vaccine misinformation, financial motivations behind it, and widespread distrust of government and health authorities (including the CDC) are major obstacles hindering measles vaccination efforts and exacerbating outbreaks.
17:08 Severe Pediatric Flu Season: The 2024-2025 flu season was particularly harsh for children, with 226 pediatric deaths reported nationally by the CDC. New York State recorded its highest number of pediatric flu deaths ever (25) this season.
18:35 High Risk for Unvaccinated Children: Approximately 90% of pediatric flu deaths occurred in unvaccinated children, with a significant portion previously healthy before rapid deterioration.
18:54 Potential Baloxavir Use in Infants: A Phase 3 study of Baloxavir (Xofluza) in children under one year old showed promising safety and efficacy, including significantly reducing viral shedding time to 24 hours, suggesting potential benefits for severely ill infants.
21:44 Positive Impact of New RSV Prevention: An MMWR report indicates that the introduction of maternal RSV vaccination and Nirsevimab for infants is associated with a substantial reduction (up to 43% overall) in RSV-associated hospitalizations among infants and young children during the 2024-2025 season compared to pre-pandemic years.
24:58 RSV Prevention Linked to Reduced Infant Mortality: An AP report suggests that the decrease in the US infant mortality rate in 2024 is partly attributable to increased RSV prevention measures.
26:30 Evidence for Zoonotic Origin of SARS-CoV-2: A Cell journal article provides phylogenetic evidence supporting a natural zoonotic origin for SARS-CoV-2, showing that bat virus ancestors were recent and likely transmitted to humans via the wildlife trade, countering lab leak theories which the hosts argue are politically motivated.
33:11 COVID-19 Increases Early Pregnancy Loss Risk: A study found that women with a history of mild or moderate COVID-19 infection before or during pregnancy had a 2-3 fold increased risk of miscarriage before 20 weeks gestation.
34:43 Development of Combined Flu/COVID mRNA Vaccine: A Phase 3 trial of Moderna's mRNA 1083 vaccine (combining seasonal flu and next-gen COVID components) showed non-inferior immune responses compared to separate standard vaccines with an acceptable safety profile, offering the convenience of a single shot.
37:29 Potential Licensing Barriers for mRNA Vaccines: Concerns are raised that despite promising data, political bias against mRNA technology within the administration/FDA may hinder the licensing of new mRNA vaccines, including the combined Flu/COVID shot.
39:11 Remdesivir Effectiveness for Hospitalized COVID-19: A real-world data study found Remdesivir treatment associated with a statistically significant 37% reduction in inpatient mortality for hospitalized COVID-19 patients, consistent with previous trial results.
44:47 Remdesivir Cost Impacts Access: The high cost of Remdesivir ($2,000/course) is discussed as a significant challenge for hospitals, leading to restricted use ("stewardship") and raising concerns about the financial burden of providing evidence-based therapy.
45:55 Long COVID Updates (Obesity & Biomarkers): A meta-analysis links excess weight/obesity to increased prevalence of neurological and neuropsychiatric long COVID symptoms. A study identified objective plasma biomarker signatures associated with specific long COVID manifestations, providing biological evidence for the condition.
48:45 Fundraiser Announcement: Reminder and encouragement to donate to the Parasites Without Borders / FIMRC fundraiser (May-July) supporting healthcare initiatives in Uganda.
49:18 Listener Questions & Advocacy: The hosts address listener questions, including recommendations for contacting members of Congress using the "Five Calls" app to advocate for science funding and public health, concerns about future COVID vaccine availability, discussion on pertussis vaccine waning immunity and schedules, and addressing a listener's query about a potential vaccine-related adverse event involving vision loss.