Injections of the Oxford/AstraZeneca coronavirus vaccine start in Northern Ireland GP practices on Monday.
A batch of 50,000 doses has been allocated, while those aged over 80 will be prioritised initially.
The region has moved to accelerate delivery of the jab as the pace of the pandemic has picked up.
The new and more infectious variant of Covid-19 has been detected in the North, as the number of coronavirus infections has increased rapidly.
Chief medical officers across the UK have decided to delay delivery of the second shot of vaccines.
The intention is that the maximum number of people receive their first jab, with its partial protection, as quickly as possible to help step the tide of cases which threatens to overwhelm the health service.
Northern Ireland is in the second week of a six-week lockdown in which non-essential retail is closed.
The region has recorded a further 1,662 cases of Covid-19.
A total of 11,810 people have tested positive in the last seven days, the Department of Health said on Sunday.
Another six people have died.
