Hi, these are oral effects of flu. Here are a few suggestions for you- 1. Continue with the prescribed medicines. Symptoms usually subside in 7-10days. 2. Keep yourself hydrated. 3. Maintain good oral hygiene. But avoid vigorous brushing of teeth. Avoid using a tongue scraper for cleaning tongue, you can gently clean your tongue with a toothbrush only. 4. Replace your toothbrush after every cold or flu episode to prevent recurrence. 5. Use a mouthwash if you feel bad taste too, u can safely use green tea water as a mouthwash as the other mouthwashes have alcohol and that can irritate your mouth. 6. Cut down on your sugar intake. Follow up with your dentist if symptoms persist for longer time. T.C. Wish you a speedy recovery.