TWiV 1319: An earful of SARS-CoV-2

This Week in Virology episode 1319 explores two major scientific developments: the ongoing challenges with poliovirus eradication and the discovery that SARS-CoV-2 can directly infect inner ear neurons, potentially causing hearing loss. The discussion begins with a review of a new study published in mBio detailing the emergence of vaccine-derived poliovirus type 2 (VDPV2) in the Central African Republic despite the use of the improved Novel OPV2 (NOPV2) vaccine. The paper reveals that recombination with non-polio enteroviruses—particularly enterovirus C—has enabled these strains to regain neurovirulence, undermining the safety improvements of NOPV2. The hosts debate the limitations of oral polio vaccines in low-resource settings and argue that the long-term solution lies in transitioning to inactivated polio vaccine (IPV), despite logistical challenges. The second major topic is a Cell Reports study showing that SARS-CoV-2 can infect spiral ganglion neurons in the inner ear via the spike protein, leading to stress granule accumulation, mTOR pathway inhibition, and apoptosis—suggesting a non-inflammatory mechanism for long COVID-related hearing dysfunction. The hosts critique the lack of hearing assessments in the mouse model and call for further research into treatments targeting mTOR or antivirals. The episode also includes listener emails on topics ranging from endangered viruses to hedgehog arterivirus outbreaks, as well as picks on environmental DNA sampling and citizen science time-lapse projects.