With a slight sore throat and new sinuses first time in over 15 years how to treat with postnasal drip and does it effect immunities and covid19? no traveling except local in n c. have 3 daughters 20,24,27 can you have covid19 with out fever?

Sure: Throat pain can be from a strep throat infection, a cold or influenza, or from some other cause such as allergies. Usually, a person sees the doctor (call first) if the sore throat is bothersome, recurrent, or doesn't go away quickly. COVID-19 infections tend to have cough, whereas strep usually lacks cough but has more throat pain. Many COVID-19 patients have no fever in early symptoms.