Anyone 60 and over in addition to First Nation, Inuit and Metis (and their non-indigenous household members 18 and over) are now eligible for fourth doses. Previously, the second booster was only available for residents of long-term care and retirement homes, in addition to those who are immunocompromised.
The recommended interval between third and fourth shots is five months although the required time between doses can be as short as three months.
Vaccines have been shown to be very protective against serious illness and death but studies has shown that antibody immunity can wane within several months (although "memory cell" protection is thought to last much longer). Additional booster shots can restore antibody levels that have faded since your last shot. Those who got a second dose last year but have not yet received a third one should strongly consider doing so now in order to restore their level of protection.
Those over 60 - the age group with the highest level of serious Covid illness - who have only three doses should strongly consider getting a fourth. Those who are uncertain may wish to consult their family doctor.
All doses are readily available at the City's vaccine clinics. I found it easy to book a fourth dose for Saturday at Willowdale's excellent Mitchell Field clinic.
To book a shot at a City clinic click here or call 1-833-943-3900 (TTY 1-866-797-0007).
For a list of pharmacies offering fourth doses click here.