Talk to General Physician on Vaccination Related Query

She is 57 years old, had right breast cancer but done with partial mastectomy on 13-october-2018. After that; she started receiving four sessions of chemotherapy and later she received radiotherapy for almost 3 weeks. She is in continuous contact with her doctor and now her latest mammography and bone scan reports are normal as expected from doctor. She is only taking 'Exemestane Normon 25mg' one tablet per day from January 2019, which her oncologist prescribed for 5 years. I just want to ask which vaccine is suitable for her? Local Chinese like Sinovac and Sinopharm or foreign ones like Pfizer, Moderna ? Which vaccine has proven least side effects for post cancer patients?