It has a mutation that may help the coronavirus partially evade COVID-19 vaccines.
The study researchers focused on the spike protein, the structure that allows coronaviruses to bind to and enter human cells.
The seasonal flu shot is a yearly vaccine administered to protect against the flu, or influenza. In the United States, flu shots are recommended for everyone ages 6 months and older.
Lab studies found that the variant was 40% better at infecting human cells compared with earlier strains.
A lifesaving operation turned tragic when a Michigan woman contracted COVID-19 from her double lung transplant last year and died soon after.
The findings highlight "the importance of preventing infections among educators in particular," the authors said.
The adorable clone, named Elizabeth Ann, was created using cells that were frozen more than three decades ago.
The researchers saw "nodules" at the back of patients' eyes, which can be signs of inflammation or direct damage to the eye.
Known as CAL.20C, the variant now accounts for nearly half of COVID-19 cases in Southern California.
In a study of 43 men who had recovered from COVID-19, nearly 20% had azoospermia, or the total absence of sperm in semen.
Called xylazine, the drug is a sedative used in veterinary medicine, and is not approved for use in humans.
Experts are particularly alarmed by this variant because of its potential to "escape" protection from current vaccines.
The case is unusual because the woman had not been previously hospitalized with COVID-19 or put on a ventilator.