Covid variant Stratus' main symptom could be easily missedThe 'Stratus' Covid variant has two forms, XFG and XFG. ‌The Stratus variant, which has two forms, XFG and XFG. Typically, Covid symptoms mirror those of common respiratory illnesses such as the flu, including fever, cough, sneezing or a runny nose. ‌However, the most frequent initial symptom of Stratus is a hoarse or raspy voice, which may precede more traditional Covid symptoms. Speaking to SFGATE, he said: "There's a little bit more sore throats with some people.