I got infecfed with covid aftter two dozes of pfizer. my mother, 66 also got the infection after 1 dose of astrazeneca and one of pfizer. we both have high fever and cough. what is the outlook according to science, now?

As soon as it is available and your symptoms of "fever and cough" disappear, a booster shot is recommended after 5-6 weeks have elapsed after the second vaccine shot. "Breakthrough" infections have been recorded even after a three shot regimen, but symptoms are usually mild. If you or your mother sustains respiratory compromise, go to an ER for an exam.

I hope Omicron is also dominant in Serbia. You should be fine but your mom is above 60 years old so you need to monitor her fever and oxygenation closely. I hope you have a pulse oximeter in your home. As long as the number above 92% she should be fine, Bring her to the hospital if it drops below 90%. At her age, tx with monoclonal antibodies is indicated but I do not thick it's available there.