LISBON: Portugal's health authority said on Wednesday it had approved the use of AstraZeneca's COVID-19 vaccine for those aged over 65 as new studies revealed its effectiveness in preventing infection and lowering hospitalisations among elderly people.

The decision means that all people aged over 18 can now receive the shot, the DGS authority said, after it was approved for those under 65 in late January.

Portugal, a nation of just over 10 million people, faced a tough battle against the pandemic in January, but the number of daily infections and fatalities has dropped sharply since then.

It reported 847 new infections and 30 deaths on Tuesday, bringing the total to 811,306 and 16,595 respectively. Around 748,000 people have so far received one dose of a COVID-19 vaccine, of whom 295,515 have had a second dose.

Other vaccines being used in Portugal include those developed by Pfizer and Moderna.

On Wednesday, the DGS also added people with Down syndrome as well as school staff to the list of priority groups for vaccination, which has thus far included frontline health workers, firefighters, care home residents and over-80s.

The decision comes a day before the government is expected to announce a plan to gradually ease lockdown restrictions that have been in place since Jan. 15, with schools expected to be the first places to reopen.