More than 5,000 volunteers involved in the Covid-19 vaccine trial in Abu Dhabi have received their first of two inoculations. On Thursday, authorities said the milestone was a "testament to the national spirit of volunteerism and strength of the healthcare system". Thousands of volunteers have signed up to take part in the clinical trial for an inactive Covid-19 vaccine, which contains a killed version of the germ that causes the coronavirus. The trial began on July 16 and first in line was Sheikh Abdullah bin Mohammed Al Hamed, acting undersecretary of the Department of Health Abu Dhabi. The department is overseeing Phase 3 of the trials in partnership with Group 42 and Chinese pharmaceutical company Sinopharm. Sheikh Abdullah received his second and final vaccine on Wednesday. "After having the first dose of the vaccine, we felt no side effects at all," he said. The tests are one of four Phase 3 clinical trials for Covid-19 to be listed by the World Health Organisation. The others include one American, one British and two Chinese. The trial being conducted in the UAE is for one of the Chinese vaccines, developed by the Wuhan Institute of Biological Products and Sinopharm. Sinopharm's inactivated vaccine passed Phases 1 and 2 of clinical trials in China without showing any serious adverse reactions. All volunteers involved in the trials generated antibodies after two doses in 28 days. The UAE was chosen as the location for the trial because of its varied demographics. To date, more than 80 nationalities are being represented in the trial. If the UAE trial is successful, the vaccine will be approved for use among the public and manufacturing will begin to produce it at scale. Nearly 5,000 people living in the capital and Al Ain signed up to volunteer within the first 24 hours, the Department of Health Abu Dhabi previously said. Thousands more have since volunteered. Among those inoculated on Thursday were Sheikh Mohamed bin Abdullah Al Qassimi and Maj Gen Faris Al Mazrouei, commander-in-chief of Abu Dhabi Police. The pair were given their first vaccination at Abu Dhabi National Exhibition Centre, where a facility able to inoculate up to 1,000 volunteers a day has been established. "I am so happy to be participating in this campaign. Thankfully, everything went well. We hope that all citizens and residents will take part in this campaign," said Maj Gen Al Mazrouei. "Today is a day we can give back something small as this vaccine is for the sake of the whole world and humanity." This week, it was announced the Phase 3 trial had been expanded nationwide, to include Sharjah. Al Qarain Health Centre has capacity for 500 volunteers and will operate daily for walk-in registrations, screenings and vaccinations. Up to 15,000 volunteers are needed for the trial, which will last between three and six months, and they must be in good health and between the ages of 18 to 60. Volunteers must visit testing centres at least 17 times over roughly 42 days and so cannot travel abroad during this time. After the trial, they should be available for regular phone consultations for up to six months. To volunteer for the Abu Dhabi trial, register your details at <a href="http://4humanity.ae/">4humanity.ae</a> or call 02 819 1111.