Ear infection by coronavirus may explain hearing, balance problems

The coronavirus can infect cells of the inner ear, researchers found in a study that may help explain the balance problems, hearing loss and tinnitus, or ringing in the ears experienced by some COVID-19 patients.

Using cellular models of the human ear, plus samples of inner ear tissues from mice and humans, researchers found that inner ear cells “have the molecular machinery to allow SARS-CoV-2 entry” and that the virus can indeed infect those cells, according to a report published on Friday in Communications Medicine by the team from MIT and Massachusetts Eye and Ear Hospital in Boston.

The virus might enter the ears via the eustachian tube, which connects the nose to the ear, or it might travel via nerves that carry smells from the nose to brain and from there via nerves that connect to the inner ear, the authors speculate.

They hope now to use their human cellular models to test possible treatments for inner ear infections caused by SARS-CoV-2 and other viruses.

CDC, FDA tally side effects from 300 million vaccines

Safety data from nearly 300 million doses of COVID-19 mRNA vaccines administered in the first six months of the U.S. vaccination program show the majority of reported adverse events were mild and brief, researchers from the U.S. Centers for Disease Control and Prevention and the U.S. Food and Drug Administration said this week. Between mid-December 2020 and mid-June this year, more than 298 million doses of the vaccines from Pfizer/BioNTech and Moderna were administered, the researchers reported on Thursday on medRxiv ahead of peer review.

The Vaccine Adverse Event Reporting System (VAERS) received more than 340,000 reports of side effects, of which 6.6% were serious but not deadly and 1.3% were fatal. Among roughly 8 million users of the CDC’s v-safe app, which surveys people about their COVID-19 vaccination experiences, more than half reported some kind of reaction, usually one day after the injection, and more often after the second dose, but fewer than 1% reported seeking medical care. “Based on the most current information,” the report concludes, serious side effects of the vaccines “are rare.”