Most people over-50 will be vaccinated within weeks, according to a senior member of the UK's vaccine committee.
Professor Anthony Harnden, deputy chairman of the Joint Committee on Vaccination and Immunisation, said that all over-50s will be vaccinated within the next few weeks.
He told BBC Breakfast: “In primary care, we’re still vaccinating cohort six – all with underlying illness – and some of seven.
“But, throughout the country, we’re going down to cohort nine.
“Most people over the age of 50 will be vaccinated really within the next few weeks – so it is tremendously successful.
“Those first nine priority groups included 99% of all hospitalisations and deaths, certainly in wave one of the pandemic, so we’re feeling very optimistic.
“We’re seeing a very sharp reduction in the deaths and hospitalisations throughout the country.”
Those aged 50 and above can now book their Covid-19 vaccination in Northern Ireland, the Department of Health said.
People have the choice of being contacted by their GPs and receiving a jab, or booking themselves in at one of the seven regional centres, if they have not already been invited to receive the vaccine by their doctor.
Vaccination centres are being migrated to AstraZeneca for first doses, to maximise use of available Covid-19 vaccine supplies.
Increasingly, the same vaccine will be provided by GPs and the regional centres.
Anyone who received the Pfizer vaccine as a first dose will still receive Pfizer for their second dose.
Health Minister Robin Swann said: “Vaccination is our bridge to better, safer and more normal times for everyone.
“Already a large and growing proportion of our adult population has received a first jab.
“Vaccination is providing vital protection from Covid-19.”
