[note 1][3] Many early cases were linked to Jamek Mosque Sri Petaling in Kuala Lumpur, which held a large Tablighi Jamaat ijtema event[4] at the end of February 2020.

[7] On 12 January 2020, the World Health Organization (WHO) confirmed that a novel coronavirus was the cause of a respiratory illness in a cluster of people in Wuhan City, Hubei Province, China, which was reported to the WHO on 31 December 2019.

[3][16] He began experiencing symptoms on 7 March and was subsequently admitted to the National Isolation Centre in Tutong.

[3] By 10 March, five additional cases were reported, all of whom were close contacts of the initial patient, bringing the total to six.

[19] On 12 March, the MoH reported 14 new cases, bringing the total to 25, with ten linked to the same event and one involving a man who had traveled to Kuala Lumpur and Cambodia.

[40] On 3 January 2021, the MoH announced the detection of 15 new COVID-19 cases in Brunei, all of which involved males aged 19 to 21 who had arrived on flight BI004 from London on 21 December 2020.

[42] To help Bruneians adjust to the new normal, the MoH announced some easing of restrictions on 7 March 2021, allowing gatherings of up to 1,000 attendees, an increase from the previous limit of 350.

Cinemas, restaurants, daycare facilities, libraries, mosques, gyms, and swimming pools were also permitted to operate at full capacity.

[44] With seven domestically transmitted cases reported on 7 August 2021, Brunei experienced a sharp increase in COVID-19 infections, prompting the reinstatement of stringent regulations.

By August 18, there were a record 513 confirmed cases, which prompted Sultan Hassanal Bolkiah to speak to the country and call for repentance and prayer for Brunei's safety.

[43] On 18 September, the government began widespread swabbing to identify illnesses in response to the continuous rise in cases.

Due to the prompt reintroduction of strict controls, case numbers started to decrease even if they were still higher than during the first wave.

[45] With commitments from Australia and Japan for 100,000 doses each, it was confirmed on 18 September that AstraZeneca would be the country's default vaccination.

[46][47] The MoH announced that priority for the second vaccine dose would be given to vulnerable groups, including the elderly, pregnant women, and disabled individuals, until the supply situation improves.

[50] Due mostly to vaccine shortages, by August 2021, just 30.3% of the population had gotten their first dosage of Brunei's mass immunisation campaign for both citizens and tourists.

The government then changed the opening time of the bridge to 6 am to 6 pm as a precautionary measure to reduce the spread of COVID.