Almost 6,500 COVID-19 vaccination slots were snapped up within the first hour of the appointments portal opening for 53 and 54-year-olds on Friday.
All Pfizer jab allocations were taken within 60 minutes despite many more AstraZeneca vaccines made available.
According to the Health Ministry, a total of 6,425 bookings were made in the first hour, with the vast majority (5,060) being Pfizer jabs.
Only 1,365 people eligible to book an appointment picked the troubled AstraZeneca shot.
The portal opened at 7.30 am Friday with some 15,020 appointments made available. It will remain open until 8 pm on Saturday.
On Thursday, the portal opened for those aged 61 to 63, with 9,000 appointments, but it soon crashed for several hours.
A total of 8,844 appointments were taken up, of which 5,389 were for Pfizer and 3,455 for AstraZeneca.
Cyprus aims to vaccinate people aged 45 and above with at least one dose by early May and cover 60% of the population by the end of June.
Cypriots are reluctant to choose the AstraZeneca vaccine after highly publicised deaths linked to rare blood clotting incidents after taking the jab.
People rushing book anything, but AstraZeneca knocked the portal offline twice in one week.
On Thursday, Cabinet ministers who had not been vaccinated received their first AZ jab, in a show of support, after the public shunned the vaccine.
So far, Cyprus has vaccinated over 20% of its 900,000 population.