Scheduled appointments are being sent to hundreds of thousands of people who have not yet had their booster jab.
Latest figures show that 83.5% of eligible adults in Scotland have now been fully vaccinated with primary doses and a booster.
From Tuesday, blue envelopes are being sent to the remainder in a “national mailshot” to encourage them to come forward for their jab.
Around 580,000 eligible adults aged 18-59 will be offered booster appointments from February 7 onwards.
Health Secretary Humza Yousaf urged people to get their booster.
He said: “While the number of Omicron cases continues to decline and restrictions are being lifted, it remains crucial that people complete their vaccination course in order that this improvement can be sustained.
“We know that in people who have had two vaccinations, protection against the virus wanes after time.
“However, recently published Health Security Agency (UKHSA) data indicates that initial vaccine effectiveness against hospitalisation of older people increases to around 90% two weeks after a booster dose.
“This is why it is so vital to get your booster so you can maximise the level of protection against serious illness.
“We urge those who haven’t yet received their booster to take up the invitations being sent out this week in the distinctive blue envelopes so that we can continue to build on the nation’s defences.
“Scotland has one of the highest uptake rates for vaccination anywhere in the world, and I hope this national mailshot will encourage the remaining adults to join the 83.5% of eligible Scots who have already received their booster or third dose.
“Vaccination continues to be the cornerstone of our battle against Covid-19, the very high vaccination rates achieved so far have helped us considerably on our path back to normality.”
Adults can receive a booster 28 days after they tested positive or if it has been at least 12 weeks since their second dose.
The letters will contain details of how to rearrange any appointment which is not convenient.
