The United Arab Emirates will consider “strict measures” to limit the movement of people unvaccinated against the coronavirus, as it seeks to ramp up a national inoculation campaign that has already administered more than 9.9 million shots.

“Strict measures are being considered to restrict the movement of unvaccinated individuals and to implement preventive measures such as restricting entry to some places and having access to some services, to ensure the health and safety of everyone,” Saif Al Dhaheri, a spokesman for the UAE’s National Emergency Crisis and Disaster Management Authority, said in a statement late Tuesday.

No further details were given for the “preventive measures” beyond restrictions on access to certain places and services in the country. The new measures would add to public health measures already in place aimed at keeping the virus at bay during the holy month of Ramadan.

The announcement sparked some negative responses online. One Twitter user by the handle Fawzia al Hashemi wrote, “Why restrict when vaccine is freedom of choice, not mandatory? When majority have taken vaccine, we are worried on them [sic] from the ones not taken? How!”

Another user by the name of Abeer Essa tweeted, “Where were the constraints on the travelers coming from the countries that were suffering from wide spread?”

The UAE’s coronavirus cases hit a peak of some 4,000 per day in late January, but have since fallen to fewer than 2,000 per day. The peak was due in large part to travelers coming to the UAE’s commercial capital Dubai for tourism, particularly from the U.K., which was then gripped by a new and more contagious variant of the virus. Dubai did not shut its doors to tourists nor restrict the movement of visitors or residents.

The UAE has overseen the second-fastest vaccination campaign in the world after Israel, announcing on Wednesday that 9.9 million vaccine doses had been administered to its mostly-expat population of roughly 10 million.

Abu Dhabi approves Pfizer-BioNTech jab

Abu Dhabi approved the use of the Pfizer-BioNTech vaccine on Wednesday, reversing course on its previous strategy of only using the Chinese-made Sinopharm vaccine.

Residents of neighboring Dubai, the Gulf country’s most populous emirate, can choose from Sinopharm, Pfizer-BioNTech, Oxford-AstraZeneca, or Russia’s Sputnik V vaccine free of charge, though Sinopharm was made universally available to adults months before the others. The UAE became the first country to approve the shot for use last year, and partnered with China, a major buyer of Gulf oil, to manufacture vaccines locally.

“The more tools we have at our disposal, the better,” Simon Bland, CEO of the Global Institute for Disease Elimination told CNBC on Wednesday. “Many countries have got several vaccine candidates that they’re using and I don’t think there is anything unusual in that, I think some diversity is valuable.”

Authorities said the Pfizer-BioNTech vaccine would be available at designated vaccination centers by appointment only. The Sinopharm vaccine, which has been the only available shot in Abu Dhabi for the general public since December, would still be available to use.

“We call on the public, both citizens and residents above the age of 16 who did not get vaccinated, to visit the nearest vaccination center and get the vaccine” NCEMA’s Al Dhaheri said. “Delaying or refraining from taking the vaccine poses a threat to the safety of society. The vaccine is our best means to recover and return to a normal life.”

Abu Dhabi opted for a Chinese-only strategy for its local vaccination drive. Most people in the emirate received the Sinopharm shot, despite a lack of details surrounding its efficacy results and peer-reviewed data.

It wasn’t clear how the decision to rollout Pfizer-BioNTech alongside Sinopharm would impact Gulf Pharmaceutical Industries, also known as Julphar, which signed a contract with Abu Dhabi’s G42 to produce the vaccine locally. A new vaccine plant with an eventual production capacity of 200 million doses a year was scheduled to be operational this year.

Julphar, G42 and The Abu Dhabi Media Office did not reply to CNBC requests for comment.