Walmart Inc, Walgreens Boots Alliance Inc, CVS Health Corp and Rite Aid Corp have told Reuters demand for flu shots at their U.S. pharmacies is up sharply - in some cases double from last year - as people try to protect themselves from influenza in the midst of a worsening COVID-19 pandemic. The pharmacies are giving millions more flu shots than they have in past years, filling a gap from COVID-19 wary consumers who are avoiding the doctor’s office.