Okay, here is the abstract and summary for the provided TWiV transcript.
Abstract:
This episode of This Week in Virology (TWiV 1206) features Drs. Vincent Racaniello and Daniel Griffin discussing current viral outbreaks and clinical updates as of April 3rd, 2025. A major focus is the escalating measles crisis in the US, with discussion on suppressed CDC risk assessments, rising case numbers (over 483 confirmed, 70 hospitalized), widespread geographic distribution, low national vaccination rates, and outbreaks extending into Canada. The conversation touches on H5N1 avian flu found in recalled raw cat food, declining but still present influenza and RSV activity, and a UK study showing real-world RSV vaccine effectiveness in older adults.
COVID-19 remains a key topic, with updates on decreasing national trends but discussion of a preprint study demonstrating the significant incremental benefit of the updated (KP.2) Moderna mRNA booster in reducing hospitalizations (~53%) and medically attended illness (~40%), particularly in adults 65+. This is contrasted with the high burden of influenza. Concerns are raised about the FDA delaying full approval for the Novavax COVID vaccine, potentially limiting non-mRNA options. Dr. Griffin critically reviews a study on metformin use in COVID-19 patients, concluding it doesn't support starting the drug for acute infection but may correlate with milder diabetes. Finally, the discussion covers Long COVID, highlighting a preprint indicating increased PASC risk following SARS-CoV-2 reinfection in children and new comprehensive Canadian guidelines for Long COVID diagnosis and management. Listener questions address measles vaccination nuances for immunocompromised individuals and Zika risk assessment.
TWiV 1206 Clinical Update: Measles Crisis, Vaccine Efficacy, and Long COVID Insights
00:00:03 Introduction: The podcast episode is identified as TWiV 1206, recorded April 3, 2025.
00:00:33 Fungal Disease Neglect: Discussion on WHO highlighting neglected fungal disease surveillance and the prevalence of conditions like Coccidioidomycosis, often misdiagnosed as bacterial/viral pneumonia.
00:02:05 Theme - Stigma and Disease: Quotation from John Green's book "Everything is Tuberculosis" emphasizing that biology has no moral compass and disease stigma is harmful and inaccurate. Relevance drawn to avoiding patient blaming.
00:04:27 Measles - CDC Muzzling: Reports that CDC leadership ordered staff not to release expert assessments highlighting high measles risk in areas with low vaccination rates near outbreaks. Key Takeaway: Concerns raised about suppression of critical public health information.
00:07:02 Measles - US Statistics Update: As of March 27, 483 confirmed US cases across 20 jurisdictions, with 70 hospitalizations (not for quarantine). A quarter of hospitalized cases are under 5 years old. Key Takeaway: The outbreak is significant and severely impacting young children.
00:08:40 Measles - Vaccination Rates: A map shows many US states are below the crucial 95% vaccination rate needed for herd immunity. Key Takeaway: Low vaccination coverage is a major driver of the current outbreaks.
00:10:26 Measles - Geographic Spread & Canada: Texas identified as a major hotspot (422 cases, 42 hospitalizations), with cases widespread across the US. Ontario, Canada also reports a large outbreak (572 cases).
00:12:10 Avian Flu (H5N1) in Cat Food: H5N1 confirmed in recalled "Savage Cat" brand raw chicken cat food after cats consuming it became infected. Key Takeaway: Highlights a potential transmission pathway via contaminated pet food.
00:13:19 Influenza Update: Wastewater and ER visits show declining flu activity nationally, though still high in some regions like New York. Future vaccine composition mentioned.
00:14:05 RSV Update & Vaccine Efficacy: RSV activity is decreasing. A Lancet study from England shows the RSV vaccine (Pfizer's Abrisvo) provided ~30% reduction in RSV-related hospitalizations among vaccinated older adults (75-79). Key Takeaway: Real-world data confirms significant protection from the RSV vaccine in the elderly.
00:16:27 COVID-19 Update: National wastewater and ER visit trends for COVID-19 are currently low or medium and generally decreasing.
00:18:49 COVID-19 - Moderna Booster Study (Preprint): Discussion of a large (N>465k) retrospective matched cohort study evaluating the effectiveness of the Fall 2024 Moderna (mRNA1273.KP.2) booster.
00:21:01 COVID-19 - Moderna Booster Efficacy: The study found the updated booster provided ~52.8% effectiveness against COVID-related hospitalization and ~40% against medically attended COVID-19 over ~2 months, compared to no fall booster, primarily in adults 65+. Key Takeaway: Recent boosters offer significant, measurable additional protection against severe outcomes.
00:22:10 COVID-19 - Booster Impact: Estimates suggest fall boosters potentially prevented ~150,000 hospitalizations and over 1 million outpatient visits during the season.
00:23:50 COVID-19 vs. Flu Burden: Comparison highlights the massive number of flu visits (20-34M) and hospitalizations (560k-1.2M) this season, suggesting flu vaccination impact could be enormous even with moderate efficacy.
00:25:35 COVID-19 - Novavax Vaccine Issue: The FDA missed its decision deadline for full approval of the Novavax vaccine; concerns raised it may not be approved soon, and current stock expires end of April. Key Takeaway: Access to the primary non-mRNA COVID vaccine option is currently threatened.
00:27:05 COVID-19 - CDC Recommendations Recap: Reminder of current CDC COVID vaccine recommendations (yearly for most, twice yearly for 65+ or immunocompromised).
00:27:51 COVID Treatment - Metformin Study Review: Analysis of a study in Scientific Reports looking at prior metformin use in elderly diabetics hospitalized with COVID. While some associations with lower severity/inflammation markers were seen (mainly >60 yrs), significant limitations (observational, small differences, confounding by diabetes severity) exist. Key Takeaway: Study does not support starting metformin for acute COVID; observed benefit likely related to better baseline diabetic control.
00:35:43 COVID Treatment - Standard Recommendations: Paxlovid (cost-effectiveness now questioned), Remdesivir, steroids, anticoagulation remain standard tools depending on disease phase/severity.
00:37:18 Long COVID - Reinfection Risk (Recover Preprint): A Recover consortium preprint study on individuals under 21 found that a second SARS-CoV-2 infection significantly increased the risk (Relative Risk ~2.08) of developing PASC (Long COVID) and specific conditions like myocarditis (~4x risk increase). Key Takeaway: Reinfection carries a substantial risk of long-term health issues in children and adolescents.
00:41:27 Long COVID - Canadian Guidelines: Researchers led by McMaster University have developed Canada's first comprehensive guidelines for diagnosing and managing Long COVID, including recommendations for prevention (Paxlovid), diagnosis (NASA lean test), and therapies (considering PEM). Key Takeaway: Provides a needed clinical framework for managing Long COVID.
00:44:05 Q&A - Measles Vaccine Transmission: Reassurance that receiving the MMR vaccine is highly unlikely to cause transmission of measles to others, even immunocompromised contacts.
00:45:24 Q&A - Measles Vaccine & CLL: For individuals with early-stage CLL ('watch and wait'), the decision to get an MMR booster (if needed due to age/previous vaccine type) is complex. Recommendation: Consult an infectious disease specialist to weigh individual risks based on CLL severity.
00:48:17 Q&A - Zika Risk in Bermuda: Currently, Bermuda is considered Zika-free. However, given concerns about CDC updates, monitoring reliable travel health sources closer to the May travel date is advised for pregnant individuals.