MELBOURNE, Dec 5 (Reuters) - Australia"s medicine regulator on Sunday provisionally approved the Pfizer Inc coronavirus vaccine for children between the ages of 5 and 11, with the health minister saying the rollout could begin from Jan. 10. The Therapeutics Goods Administration "have made a careful, thorough assessment, determined that it is safe and effective and that it is in the interests of children and Australians for children 5 to 11 to be vaccinated," said Health Minister Greg Hunt. After initial delays with its general COVID-19 inoculation programme, Australia has swiftly become one of the world"s most-vaccinated countries, with nearly 88% of Australians over the age of 16 having received two doses. The high vaccination has helped slow the spread of the virus and promote a speedy economic recovery, with the government planning to raise its 2022 growth forecast within weeks.The efficacy of vaccines against the new Omicron variant, which is spreading in Australia, remains unknown. The most populous state, New South Wales, reported two more Omicron cases on Sunday, bringing the total to 15 cases, and the Australian Capital Territory confirmed its second. Parliament House was closed over the weekend to the public until further notice after a staffer to a member of parliament tested positive to COVID-19 after the legislature"s final sitting week of the year on Friday. The variant of that infection case has not been disclosed, but health authorities said the staff was fully vaccinated. While nationwide vaccinations are voluntary, states and territories have mandated shots for many occupations, and some require full vaccination to access most hospitality services and non-essential retail. Australia"s overall childhood immunisation coverage is also one of the highest in the world, with 95% of 5-year-olds inoculated with vaccines recommended for their age, health data showed. The Pfizer vaccine for those children still needs the approval of the Australian Technical Advisory Group on Immunisation. Once approved, it will be available to about 2.3 million children in the 5-to-11 age group. Despite battling many outbreaks this year, leading to months of lockdown in Sydney and Melbourne - Australia"s largest cities - the country has had only about 834 confirmed COVID-19 cases and 7.9 deaths per 100,000 people, according to the World Health Organisation, a fraction of the toll in many other developed nations. Australia has had just under 217,000 cases in total and 2,042 deaths.