Patricia Donnelly said people can get their booster doses at a number of vaccination clinics running this week.
She also emphasised that vaccine first doses for everyone aged 12 and over continue to be available at Health Trust vaccination centres.
Ms Donnelly said: “Our great vaccination teams will be hard at work once again this week, providing boosters to as many people as possible.
“There are so many opportunities across Northern Ireland for people to get their booster dose before the start of the New Year.
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“I know some people had been putting it off until after Christmas and I would appeal to them to delay no further.
“We are facing a very serious threat from Covid-19 and getting boosted is the single most important thing you can do to protect yourself.”
She added: “The Health Trust vaccination centres are also continuing to offer first doses to people aged 12 and over. Young people can therefore get their jab before the end of the school holidays.
“People aged 18 and over are also still coming forward for their first jabs. To those not yet vaccinated, my same plea applies - please don’t delay any further.”
Details of Trust vaccination centre opening hours this week are published online.
For the very latest information, check Trust websites and Trust social media channels.
Booking for booster jabs at Health Trust vaccination centres is open to everyone aged 18 and over. To be eligible for a booster, it must be at least three months since your second jab.