Those who have not yet had their spring Covid booster are being urged to come forward amid “another wave” of infections of the virus in Scotland.
Additional vaccinations have been offered to people over 75 or those aged over 12 who have underlying health conditions.
It comes just 11 days before clinics are set to close on June 30.
Scotland’s national clinical director has caught coronavirus for the first time amid warnings that infection numbers could be “substantially higher” than one in 30.
Jason Leitch shared an image of his positive lateral flow test on Saturday as he said “global and Scottish cases are rising”.
Public health experts have warned the lack of surveillance monitoring means infection levels were unknown.
In April, the Scottish Government ended regular testing of the public with free lateral flow kits no longer available.
PCR sites closed and people with symptoms were no longer told to seek a test.
The Office for National Statistics estimates one in 30 people are infected with coronavirus, but public health experts have warned the number could be “substantially higher”.
Health secretary Humza Yousaf said: “I am pleased so many people have come forward for their spring booster, which provides important extra protection for our most vulnerable groups.
“Vaccination has been our most effective tool against coronavirus. However, the degree of protection offered wanes over time.”
Before the changes to routine testing were made, Emma Thomson, professor in infectious disease at the Centre for Virus Research, told STV News maintaining the ability to do surveillance was “critical”.
Professor Thomson said the biggest concern was an ongoing threat of immunity waning in the general public making people more vulnerable to the virus and the emergence of new variants which are even more immune evading than Omicron.
The European Centre for Disease Prevention and Control reclassified Omicron sub-lineages BA.4 and BA.5 from variants of interest to variants of concern in May.
“We are seeing higher numbers of infections across our communities at the moment which is why booster vaccination is needed to maintain the best protection against Covid-19 for those at highest risk of severe effects from the virus,” Yousaf said.
“Almost 90% of over-75s and around two thirds of those who are aged over 12 and are immunosuppressed have already taken up the offer of a spring booster and if you have missed yours for any reason then you can rearrange it online at NHS Inform or by calling the helpline on 0800 030 8013 seven days a week between 8am and 8pm.
“We continue to encourage everyone to receive the doses they are eligible for as and when they become available.”
Anyone in the eligible groups can book online or call the national vaccination helpline to book an appointment.
Some health boards are also operating drop-in clinics and details can be found on their websites.