COVID-19 vaccine booking system launches at 8 a.m. today for those aged 80 and up.Qualifying residents can visit the online portal or call a hotline to book their appointment.But Premier Doug Ford is urging those who don’t yet qualify for a shot to keep off the website so that it doesn’t crash.Some of Ontario’s 34 public health units have already established their own systems for booking vaccination appointments, but the provincial portal will either enhance or replace those setups in many areas.