The invitations will begin with seniors living near polyclinics or vaccination centres.
The ministry says it expects to have opened a vaccine centre near each town by mid-March, so all seniors can be covered. This will bring the total number of centres to 31 from 11 as at Feb 19.
It adds that all seniors should receive their letters by the first week of March.
Following the vaccinations of seniors aged 70 years and above, seniors aged between 60 and 69 years will receive their invitation letters around mid-March. Their vaccinations will commence around end-March.
Letters will be mailed to their official residential addresses.
As at Feb 18, about 250,000 individuals have received their first dose of the Covid-19 vaccine.
Some 110,000 among this number have received their second dose.
