[debono]

Yellow phlegm is not COVID la. Most likely bacteria infection...see a doc to take antibiotic. COVID got white phlegm and the cough will continue non stop....almost like can rest for a few mins each hour only...then the flu will come and the phlegm also white and your nose will be blocked and you will be weaken and become difficult to breathe....your symptom is more like eat something unhygenic and the germs infect your throat.

I agree with your prognosis, he need antibiotics to clear his sore throat.... ............