Most clinics have walk-in appointments, so it shouldn’t be a problem. If you’re going to be late to your appointment, it’s best to contact the location where you’re scheduled to see if you can still get vaccinated. You can call 211 to cancel or reschedule at any time. If it is 48 hours or fewer before your appointment, you can cancel or reschedule by following the link in the reminder notice that you get by text or email.