Timeline of the COVID-19 pandemic in Vietnam

The first two confirmed cases in Vietnam were admitted to Cho Ray Hospital, Ho Chi Minh City on 23 January 2020. They were a 66-year-old Chinese man and his son, the former have traveled from Wuhan to Hanoi to visit his son who was believed to have contracted the virus from his father when they met in Nha Trang.[1] The first cluster also appeared in Son Loi Commune, Bình Xuyên District, Vĩnh Phúc after a few workers returned from a business trip in Wuhan and infected other people in close contact with them.[2] The Vietnamese government immediately locked down Bình Xuyên District until 4 March 2020 to prevent the disease from spreading all over the country. Having known cases early is one of the main reasons why Vietnam was successful in fighting the virus. For the first 16 cases of the disease, the medical staff had to treat different types of patients, including infants, the elderly and people with underlying conditions. This is like "an exercises" for the Vietnamese medical system in order to prepare and study the new virus.[3][4]

When the pandemic spreads across the globe, the coronavirus cases in the country also surged, and on the evening of 6 March, Hanoi Department of Health confirmed the first case in the capital, a 26-year-old woman who had travelled to Europe. This is the 17th case in Vietnam.[5] On the afternoon of 20 March, the Ministry of Health announced 2 new COVID-19 patients, the 86th and 87th, who were two female nurses at Bach Mai Hospital with no history of contact with any COVID-19 patients.[6] In March and April 2020, the number of cases increased rapidly due to the large number of people coming from European countries and the appearance of clusters such as Bach Mai Hospital, Ha Loi Commune in Hanoi and Buddha Bar in Ho Chi Minh City.[7][8][9]

After 21 March 2020, Vietnam suspended entry for all foreigners from midnight of 22 March, and introduced concentrated isolation for 14 days in all cases of entry for Vietnamese citizens.[10] From 1 April, Vietnam implemented nationwide isolation for 15 days.[11] On the same day, Prime Minister Nguyen Xuan Phuc announced the nationwide outbreak of COVID-19.[12] The drastic epidemic control measures had positive results and the country did not confirm any cases of local transmission from mid-April to the end of July.[13][14]

The country entered a second wave of infection when the Ministry of Health announced the 416th case in Da Nang, which was the first case with an unknown source of infection in 99 days.[15][16] On 28 July, the Da Nang authorities immediately locked down the city for 15 days.[17] Hundreds of cases across the country with epidemiological factors related to Da Nang were furthermore detected,[18] and the first death was also recorded on 31 July.[19][20][21] After two months, by using the same strategies that have been used in the first outbreak, Vietnam has successfully contained the disease for the second time and has resumed almost all economic activities, including international commercial flights.[22][23] Sporadic community infections continue during November and December, causing public scare and heightened measures.[24][25]

The third wave of infections began on 28 January 2021, when Vietnam recorded an additional 84 community transmission cases within a single day in Hai Duong and Quang Ninh provinces. These cases are all related to patients 1552 and 1553, who both came into close contact with a Hai Duong migrant worker diagnosed with the UK coronavirus variant by Japanese authorities after arriving in Osaka on 17 January.[26]

On 14 January, two Chinese tourists with fever symptoms from Wuhan were quarantined by the authorities and placed under observation after they landed at Da Nang International Airport. Hanoi dispatched a medical team to the coastal city and called an emergency meeting the next day on prevention efforts.[27]

On 23 January, Vietnam confirmed the first two cases of COVID-19.[28] Vietnam Ministry of Health issued two hotline numbers for information on the coronavirus disease, and advised citizens to contact the nearest healthcare center if they had its symptoms.[28] On 24 January, Acting Minister of Health Vũ Đức Đam ordered the activation of the Emergency Epidemic Prevention Centre.[29] Vietnamese doctors documented and reported the two cases to medical journal The New England Journal of Medicine, at that time this was the first concrete evidence to the scientific community about human-to-human transmission of the disease outside China.[30][31] On 29 January, the 2nd COVID-19 patient had fully recovered and was discharged.[32] His father, who was the 1st COVID-19 patient in Vietnam, was discharged on 12 February.[30]

On 29 January, the Ministry of Health established 40 mobile emergency response teams, on stand-by to assist affected locations, for quarantining, disinfecting, and transporting patients or suspected patients.[33] A week after the first two cases, three positive cases were confirmed by the Ministry of Health, involving Vietnamese nationals who had returned from Wuhan. Case No. 3 (25-yr-old female) was quarantined and cured in Thanh Hóa Province, while the other two cases (#4: 29-yr-old male; #5: 23-yr-old female) were hospitalised in Hanoi.[34][35] Case No. 5 was discharged on 3 February, fully recovered and after testing negative for the virus.[36]

Vietnamese panic buying instant noodles in supermarket during the pandemic.

On 1 February, a 25-year-old woman (#6) was declared coronavirus-positive in Khánh Hòa Province. She has worked as a receptionist and had direct contact with the Chinese father and son (cases #1–2).[37] This case was discharged from the hospital on 4 February.[38] Noticeably, this case was the first domestic transmission in Vietnam, leading to an epidemic declaration signed by the Vietnamese Prime Minister and calls for border tightening, aviation permits revoked, and visa restriction.[39][40][41][42]

On 2 February, a Vietnamese American (#7) got infected with coronavirus, due to two-hour layover in Wuhan airport during his trip from the US.[43]

After 3 February, everyone entering from China to Vietnam must comply with the 14-day epidemiological check-up and health-monitoring procedure to ensure that the COVID-19 epidemic does not getting worse.[44]

On 3–4 February, Vietnam announced their eighth and ninth case: a 29-year-old female (#8) and a 30-year-old male (#9). They belonged to the same training team with the previous confirmed cases of three (cases #3-through-5).[45][46]

Later on 4 February, the 10th case was identified. A 42-year-old female met and greeted with the case No. 5 during Lunar New Year holiday.[47] Mother (49-year-old, #11) and younger sister (16-year-old, #12) of the case No. 5 were also transmitted on 6 February.[48]

On 7 February, Vietnam confirmed their 13th case, a 29-year-old worker, a member of the same training crew as the 5 previously confirmed cases (case #3,4,5,8,9).[49]

Earlier of the same day, Vietnam declared to have successfully cultured and isolated the virus in the lab, one of the early countries to do this, along with Singapore, Australia, Japan and China.[50]

On 9 February, a 55-year-old woman, a neighbour of case No. 5, tested positive; the 14th case.[51]

On 10 February, three more cases: #4, #5 and #9 were declared to be recovered.[52]

The 15th case was identified on 11 February, a 3-month-old grandchild of case No. 10.[53] This case also marked the 10th case found in Vinh Phuc and prompted Vinh Phuc province leadership to implement quarantine of the at-risk village named Son Loi with more than 10,600 people, activating mobile food shops and handing out free masks to all villagers, in an effort to contain the spread of the virus.[54] 10,600 villagers were divided into groups of 50–60 households each, each group assigned to a supervision team responsible for daily household visits and health-checks. The quarantine of Son Loi village was scheduled to last 14 days.[55]

On 13 February, father of case No. 5 was tested positive, making the number of cases in Vietnam 16.[56]

On 25 February, the 16th was released from the hospital after being tested negative from the COVID-19, temporarily made Vietnam cleared from COVID-19 outbreak.[57] However, quarantine measures continue to be imposed until further notice.[58]

On 3 March, after 20 days without new case of coronavirus, Son Loi village was approved to remove quarantine.[59]

CGV Cinema temporarily closed at Hanoi Times City in March 2020.

A quarantine area in Vietnam during COVID-19

On 6 March night, Hanoi urgently announced a new case of coronavirus, the first one found in the capital of Vietnam. The patient (case #17), a 26-year-old woman, had been travelling across Europe during the outbreak. She had been exhibiting several symptoms, but didn't cooperating with the authorities about her travel history or health conditions to avoid quarantine.[60][61] Within the night, the government proceeded to track and isolate roughly 200 people who either had close contact, lived on the same street, or had been on the same flight VN0054 from London as patient No. 17.[62][63] The incident also sparked a wave of stockpiling purchases across the city.[64]

On 7 March afternoon, a 27-year-old Vietnamese was diagnosed with COVID-19 and moved into quarantine in Ninh Bình Province for treatment, making this the 18th case. This patient had previously been in Daegu for several days in February and, prior to testing positive, had already been quarantined – along with all passengers on the same flight from South Korea – since he re-entered Vietnam.[65] Just 2 hours later, the Vietnamese Ministry of Health confirmed 2 more cases (#19-#20) in Hanoi, both related to the 17th case.[66] The same day, Hanoi city expanded the scope of contact tracing to F5 and raised the quarantine procedures by one level, meaning F1 to be quarantined in hospitals and treated the same as a patient case, F2-F3 to be moved into central quarantine, and F4-F5 to self-quarantine at home, with temperature checked twice per day.[66]

On 8 March, another case in Hanoi was announced, which was a 61-year-old man.[67] Later this day, 9 more cases was announced, with 4 cases in Quảng Ninh, 2 cases in Lào Cai, 2 cases in Đà Nẵng and 1 case in Thừa Thiên – Huế. All ten cases (#21-#30) were foreigners tracked from the same flight into Vietnam with case No. 17.[68]

On 9 March evening, a 49-year-old British man was tested positive (case #31) and put into quarantine in Quảng Nam Province, previously on the same flight with patient number 17.[69]

On 10 March, a 24-year-old Vietnamese woman who had just returned from England and previously had close contact with case No. 17 while in London, tested positive (case #32). She had flown back to Vietnam in a private jet with quarantined cabin – after becoming aware that case No. 17 was infected – to seek healthcare in her home country.[70] Later that day, another British man was found infected with the virus (case #33), who was on the same flight with case No. 17.[71] Before the end of the day, the 34th case was identified, a 51-year-old businesswoman who had visited the United States, with a brief transit in Korea and Qatar during the trip.[72]

On 11 March, Vietnam confirmed their 35th case of COVID-19, a 29-year-old woman who works in an electronics supermarket in Da Nang, and had physical contact with two infected British tourists.[73] Within the same day, 3 more case were discovered (#36-#38), all are related to patient number 34.[74]

On 12 March morning, Vietnamese Ministry of Health reported the 39th case of the country. This case is a 29-year-old tour guide in Hanoi, who had contact with patient number 24 during a trip to Ninh Binh.[75] Evening of the same day, five more cases were announced (#40-#44), all are related to patient number 34.[76]

On 13 March three more cases (numbers 45 to 47) were announced, related to case No. 34, case No. 17, and the flight VN0054 from London.[77][78]

On 14 March 6 cases were announced (numbers 48 to 53). Aside from cases related to flight VN0054 and patient 34, there are 3 unrelated cases: A Vietnamese came back from Paris, a Vietnamese overseas student who has been travelling across Europe, and a Czech national.[79]

On 16 March, a new case was reported in Vietnam, known as the 61st patient. The patient, a Muslim from the Cham minority, had participated in the Tablighi Jamaat in Sri Petaling mosque, Malaysia, where he got infected before returning to Vietnam and attended the Jamiul Muslimin Mosque in Ho Chi Minh City before returning home in Ninh Thuận. Due to the wide range of people he contacted, it raised the fear of the patient being a super spread patient. Eventually, the Vietnamese authorities decided to isolate and quarantine the whole province, as well as shut the mosque.[80][81][82] Subsequently, a new-found case connected with the man were also discovered the following days.[83] On 22 March, another case also related to the Islamic activities is a fellow Muslim who returned from Malaysia also attended in the same Sri Petaling mosque, before went back to Vietnam and still did Islamic praying five times a day in Jamiul Anwar mosque, despite being asked to quarantine at home.[84]

On 22 March, Vietnam recorded over fourteen new patients, surpassing over 100 patients for the first time. Many returned from various countries, including Britain, Malaysia, and France; which were at the time severely hit by coronavirus.[85]

On 26 March 12 more cases were confirmed.[86]

Doctor taking blood sample for COVID-19 rapid testing at Hoang Mai Market, Hanoi.

From 17 to 23 April, no new cases were confirmed.[87][88] However, there were reports of cases who tested positive again after being discharged.[89][90] On 22 April, People's Committee of Đồng Văn District decided to lockdown Dong Van town for six days after confirmed the first cases in the province on 16 April.[91]

On 24 April, two more cases were confirmed: both were Vietnamese students who came back from Japan and quarantined on arrival.[92]

A previously discharged patient in Hà Nam was pronounced dead on 4 May, later confirmed to have died from liver failure and not COVID-19. The patient had previously gone to the hospital on 20 March to treat last stage of liver disease, before testing positive for COVID-19 on 7 April. He received treatment for it and was subsequently discharged on 17 April after testing four times negative from coronavirus.[93][94]

On 15 May, Vietnam confirmed 24 new cases, all of them from a repatriating flight from Russia and quarantined after arrival in Thai Binh and Quang Ninh, raising the total number of COVID-19 cases to 312.[95]

On 29 May, after a long period without any confirmed cases of local transmission, Vietnam Airlines announced that it had completely restored its domestic flights after months under lockdown; international flights, however, remain suspended.[96]

On 25 June, a flight from Japan to Vietnam took off from Narita International Airport; this was the first flight since the two countries agreed to ease travel restrictions which were imposed due to the COVID-19 pandemic. More flights to Vietnam are scheduled in the coming months by other countries.[97][98]

On 6 July, a group of doctors who had been overseeing the treatment of “Patient 91”, a British pilot who was Vietnam's most critical COVID-19 case, announced that he “has made substantial progress and his health condition allows him to travel”. The patient was discharged from Cho Ray Hospital in Ho Chi Minh City a few days later.[99][100]

As of July, Vietnam had gone more than three months without new COVID-19 cases from local transmission. All recent cases were people who had been infected abroad and who had been placed in government quarantine facilities after arrival in Vietnam.[101]

Da Nang C Hospital. After detecting the patient positive with COVID-19 visited there, the authorities decided to quarantine the hospital with everyone inside it for at least 14 days.

On 22 July, a 57-year-old man went to Da Nang C Hospital coughing and feeling tired. After diagnosing him with pneumonia, the doctors took samples for testing for COVID-19, and got a positive result. His samples were sent to the Pasteur Institute in Nha Trang and to the National Institute of Hygiene and Epidemiology in Hanoi for more tests and the results also came back positive.[102]

The night of 23 July, the Da Nang Center for Disease Control and Prevention (Da Nang CDC) took samples from more than 100 people thought to have been in contact with the man during the previous days, including his family members, and all of them tested negative. More than 50 people who had been in contact with the suspected patient at the Da Nang C Hospital were quarantined immediately and the hospital was locked down the next day. In the afternoon of 24 July, the man suspected of being infected with COVID-19 was suffering from acute and severe pneumonia and had to be supported by ECMO. The Ministry of Health determined that the possibility it was a positive case was very high. The Deputy Director of the Da Nang Department of Health said the patient was being treated at the Da Nang Hospital Department of Tropical Medicine.[103]

On the same day, the Vietnamese Acting Minister of Health Nguyễn Thanh Long ordered the city authorities to suspend all international flights at Da Nang International Airport.[104] The ministry rolled out extensive countermeasures and immediately sent a group of doctors from Cho Ray Hospital in Ho Chi Minh City to Da Nang to assist with the case. Deputy Prime Minister Vũ Đức Đam, head of the National Steering Committee for COVID-19 Prevention and Control, urged all competent forces to remain vigilant and stand ready to deal with new developments of the pandemic.[105] On 25 July, the Ministry of Health confirmed the case in Da Nang, ending 99 continuous days of Vietnam not confirming any local transmission cases.[106][107]

After the case was confirmed, Prime Minister Nguyễn Xuân Phúc ordered the Ministry of Public Security to investigate and deal with a crime ring that illegally trafficked foreigners into Da Nang and Quang Nam. The police arrested three people, including two Vietnamese nationals and one Chinese national for "organizing illegal entry into Vietnam" after they found that dozens of Chinese nationals were illegally crossing the border. Recent reports of a large number of foreigners, mainly Chinese, illegally entering the country, showing "lax immigration management".[108]

On 26 July, Da Nang confirmed three more cases in community. Case #418, a 61-year-old man living in Hải Châu District, was in serious condition, and had to use a ventilator. Authorities are investigating whether this case related to the previously discovered patient in Da Nang one day earlier. Two remaining cases (Case #419 and #420) are a 17-year-old teenager and a 71-year-old woman, all of whom were related with Da Nang C Hospital.[109][110]

Four days later, the country confirmed dozens of cases in five cities and provinces all related to Da Nang.[111][112][113][114]

On 31 July, Vietnam confirmed 82 new cases, including 45 cases in Da Nang, 20 cases in Hanoi, 8 cases in Quang Nam Province, 6 cases in Ba Ria-Vung Tau Province, and 3 cases in Ho Chi Minh City.[115][116] On the same day, the first two deaths due to COVID-19 occurred in Vietnam: patient 428 and 437, two elderly 70 and 61 years old man respectively, who appeared to have contracted the virus in Da Nang.[117][118]

Bulkhead barrier in a restaurant in Hanoi. From the 19th of August, bars and restaurants which do not follow epidemic prevention protocols will be fined and forced to close.[119]

More than 200 health workers from all over Vietnam are sent to the central coastal provinces to support the epidemic prevention. The Cuban government also sent a team of health experts into the epicenter, Da Nang.[120]

On 6 August, Vietnam confirmed its tenth death, the first to be diagnosed as having COVID-19 after death.[121] The authorities began mass testing around the country for people coming from Da Nang in July.[122]

On 7 August, an officer of the 377th Air Defence Division tested positive and the local health officials immediately quarantined 14 close contacts. This was the first case related to military personnel in the country.[123]

On 14 August, the Vietnamese government decided to isolate Hải Dương city for 15 days after four residents tested positive, none of whom had travel history to Da Nang.[124] On the same day, the Ministry of Health announced that Ho Chi Minh City had 1 new case of COVID-19, patient 912, a Chinese man who crossed the northern border illegally into Vietnam.[125] Out of 152 cases of illegal entry discovered in Ho Chi Minh City since May, Chinese people account for 72%, Cambodians 11%, and the rest were Vietnamese and Korean, the Center for Disease Control in Ho Chi Minh City (HCDC) said. This raises concerns about an outbreak from people who entered illegally into the city area.[126]

On 30 August, Vietnam recorded its first day without new cases since the beginning of the second outbreak.[127]

From 1 September, Vietnam started charging people coming from other countries for quarantine and reduced the 14-day centralized quarantine policy to maximum seven days for foreign experts, investors, managers, and diplomats entering the country for less than two weeks. After this period of time, if a person tests negative for the coronavirus, they can remain in Vietnam.[128][129] The Civil Aviation Administration of Vietnam (CAAV) have prepared detailed plans for resuming commercial flights to six Asian destinations such as Seoul, Guangzhou, Tokyo and Taipei from 15 September with around 5,000 foreign passengers scheduled to arrive in Vietnam per week. Passengers must provide COVID-19 negative certificate issued by the host country within three days before boarding.[130]

After the central government considered that the COVID-19 outbreak has been brought under control, on 7 September, Da Nang has decided to ease its social distancing restrictions, and all passenger transportation and business enterprises resumed normal operations.[131] On the same day, all 180 bars and discos in Ho Chi Minh City re-opened.[132]

As of 28 October, Vietnam has not found any new cases of community transmission.[133] However two cases who had just left the country were detected by the Japanese authorities. The first one was a 33-year-old Japanese businessman who had been working in Hai Phong since June. When he arrived at Kansai International Airport, he was tested by PCR and on 5 October the result came back positive.[134] After being informed about the case, the Hai Phong Department of Health isolated 152 close contacts and quarantined the hotel he had stayed. Two days later, all 152 test results came back negative.[135] The second case was a 48-year-old South Korean expert who was residing in Ho Chi Minh City and tested positive for COVID-19 after leaving the city for Japan on 25 October. City health officials quarantined 343 close contacts and tested them; all the tests were negative.[136]

On 29 November, the Ministry of Health recorded a newly confirmed case of COVID-19 known as patient 1342, he was a 28-year-old male Vietnam Airlines flight attendant who returned to Vietnam from Japan on 14 November. Upon arrival in country, the flight crew members were quarantined in a quarantine facility of Vietnam Airlines in Ho Chi Minh City. After two negative tests, the flight attendant was allowed to be home-quarantined at his rented apartment in Tân Bình District. During the home-quarantine, the flight attendant has had direct contacts with three people including his mother and his two friends (one male and one female). On 28 November, sample was taken from the flight attendant for the third time and showed positive results for SARS-CoV-2. Investigation revealed that previously, during the period of 14–18 November, while in the centralized quarantine facility, patient 1342 had contact with a colleague known as patient 1325 from another flight from Romania.[137]

On 30 November, the Ho Chi Minh City Center for Disease Control (HCDC) announced one case tested positive for COVID-19, a 63-year-old female in Hóc Môn District (mother of patient 1342), without confirming the case. After an investigation, 5 people who had had close contact with the patient were identified; none of them wore face masks. The authorities also conducted disinfection procedures at the places the patient lives and had visited.[138] On the same day, the HCDC confirmed one more case, an English teacher (friend of patient 1342) living in District 6. On the afternoon of 30 November after receiving the information, Minister of Health Nguyễn Thanh Long convened an emergency meeting with the Ho Chi Minh Department of Health to implement full pandemic prevention measures across the city. At the meeting, it was announced that the newly discovered positive case was directly related to patient 1342 announced on 29 November. This was the first new case after the city went four months without confirmed cases from community transmission.[139][140]

On 1 December, Ho Chi Minh City announced two more cases. One was a one-year-old boy in District 6. His parents had sent him to patient 1347's home to look after him a few days previously. On 30 November, after patient 1347 tested positive, the HCDC put him and the mother in quarantine at the City Children's Hospital. The father and other family members were quarantined at home. The second one was a 28-year-old female student of patient 1347 at an English language center. Nine people in close contact with this female student were quarantined.[141] Eight primary, secondary, and high schools closed,[142] 12 universities have been closed since 2 December until further notice, consequently approximately 8,200 pupils, 160,000 university students and 6,000 lecturers are off from schools and universities, all school exams, meetings, conferences, out-door activities have been cancelled or postponed, three residential areas with 148 households and 485 people are on temporary lockdown. In Hanoi, the authorities also requested suspension of unnecessary mass gathering events.[143][144] After contact tracing for the latest four patients, the city has placed under supervision 861 close contacts (F1), 1,400 people exposed to F1 (F2) and 1,002 others. They have all tested negative for the virus, the HCDC announced on 7 December.[145]

In the emergency meeting in response to the COVID-19 outbreak on 1 December in Hanoi, PM Nguyễn Xuân Phúc announced that international commercial flights would be halted and everyone entering the country would have to be quarantined in military barracks or local quarantine areas. Enterprise-managed quarantine was abolished after one person quarantined at a Vietnam Airlines facility spread COVID-19 to the community. From January 2021, foreigners will not be allowed to enter Vietnam to ensure safety for the major political event of the country, the 13th National Congress of the Communist Party.[146]

On 9 December, following the instructions of the People's Committee of Ho Chi Minh City, the HCDC had conducted random COVID-19 testing at Mien Dong Coach Station to ensure that no infections are missed in the community. This is the largest bus station in Ho Chi Minh City in terms of the number of passengers transported each year and in terms of daily bus traffic.[147]

On 26 December, a 32 years-old man known as patient 1440, live in Vinh Long Province has tested positive for the COVID-19 after illegally entering Vietnam. He was driven to a border gate in southern Vietnam two days ago then to Ho Chi Minh City, then got on a different bus to Vinh Long. Throughout his journey, he had made contact with several other people. On 28 December, four apartment blocks in District 5, Ho Chi Minh City were locked down after a man in the area tested positive. The 23-year-old man had stayed with patient 1440 in Myanmar before they crossed the Vietnamese border with other seven people.[148][149] On 29 December, two more people in that group tested positive.[150]

On 2 January, Vietnam reported a detection of the UK variant of SARS-CoV-2 in a 45-year-old female, a resident of Tra Vinh province who returned from the United Kingdom on 22 December on flight VN50. All the 305 passengers from this flight were quarantined upon the arrival in Tra Vinh (147 people), Vinh Long (137 people), Can Tho (17 people) and Ho Chi Minh City (4 people). The patient is being treated at Tra Vinh Tuberculosis and Lung Disease Hospital with fever and sore throat. Full genome sequencing of the case revealed variant VOC 202012/01 that was reported from the UK, it was also discovered that this strain also had the D614G mutation, which is believed to spread rapidly in Da Nang 4–5 months ago.[151] On 5 January, PM Phuc ordered to suspend flights from countries and territories infected with the new variant, the first two are South Africa and the United Kingdom.[152]

On the same day, a 22-year-old man, known as patient 1498 left the quarantine facility before receiving positive result. Epidemiological investigation showed during the 14-day quarantine period, he had tested negative for the virus once. On 4 January, after completed isolation, his samples were taken for a second test, and without waiting for results, this person was released from the facility. Five family members picked him up by car and returned to Ha Long were subsequently quarantined and had their samples taken. The hotel where he and his family had stayed has been temporarily locked down while authorities also disinfected the nearby restaurant and car in which they traveled.[153] Patient 1498 were put in quarantine at the 59th Infantry Regiment in Chuong My District from 21 December 2020 with 88 other people. This group of people was tested twice by Hanoi CDC. The first time, they tested negative for COVID-19. The second time, 84 negative samples returned on 3 January, 5 samples had no results. On January 4, Hanoi CDC returned the test results of the remaining 5 people, including patient 1498. However, the deputy director of Chuong My District Medical Center mistook the number of people with negative test results. So he signed an end of quarantine term with two negatives for all 89 people, instead of 84 people. This is the main reason why patient 1498 are allowed to end the quarantine period before the second test results are available.[154]

In January 2021, Vietnamese government announced a stricter quarantine policy to “protect the country” during 2021 Lunar New Year. Everyone entering country must be isolated for at least 14-day at the government’s quarantine facilities, only special diplomats identified as such by the Ministry of Foreign Affairs would be exempt. The Ministry of Defence ordered the military to bolster troop numbers along borders to prevent illegal entrants trying to enter the country through trails to avoid being quarantined, since a large number of Vietnamese working in neighboring countries are seeking to return home for Tết in many ways.[155][156]

On 28 January, Vietnam Ministry of Health confirmed two community cases of Covid-19 in Hải Dương and Quảng Ninh. The first patient was a 34-year-old woman working for Vietnam Poyun Electronics in Hải Dương, she had come into close contact with another female worker who had been confirmed positive when arriving in Japan on 17 January. The second patient was a 31-year-old staff at the Van Don International Airport in Quảng Ninh, this airport has served many repatriation flights amid the pandemic. Both patients are treated at the National Hospital for Tropical Diseases in Hanoi.[157] On the same day, the Japanese authorities announced the RT-PCR results of the 32-year-old girl imported from Vietnam on 17 January, according to the announcement, she had infected with the new coronavirus variant discovered in the UK. Vietnamese authorities are still unable to explain why she has this variant since she has never had contact with people infected with COVID-19.[158] In the noon of 28 January, the country reported 84 new cases in Hai Dương and Quang Ninh, being the highest number of new cases in a day. These cases are all related to patients 1552 and 1553, who both came into close contact with a Hai Duong migrant worker diagnosed with the UK coronavirus variant by Japanese authorities.[159][160] In response, all public transportation including flights cannot enter or leave northern Quang Ninh Province from 06:00, 28 January;[161] while Hai Duong commenced province-wide social distancing measures six hours later.[162]

The Health Ministry on 29 January ordered all medical facilities across the country to urgently testing for all healthcare workers amid the resurgence of COVID-19. Hospitals are also required to take samples of all patients in departments of emergency, emergency resuscitation, intensive care and random samples of at least 30% of patients in the remaining departments to early detect potential cases.[163]

At a meeting on 31 January, Hanoi People's Committee announced the decision to close all bars, karaoke parlors, and discotheques, residents are required to avoid non-essential gatherings from 1 February. The city also tested people who traveled from Hai Duong Province's Chi Linh City from 1 January and Van Don International Airport from 5 January.[164]

As of 6 February 2021, Vietnam had four large COVID-19 clusters:[166][167]

• Van Don International Airport cluster: appeared first with the first recorded case, he was a security officer known as “Patient 1553”. From this case, Quang Ninh officials have tracked 4,395 contacts and took 1,252 samples, 13 are positive, all of the cases were from airport staffs. The source of the infection and when it started is unknown. Some experts assumed the source might be from people entering the airport. Right from the beginning of the pandemic, the airport became a specialized place for humanitarian flights from abroad. Therefore, this place has a very high chance of infection from immigrants. After detecting the case, Van Don airport stopped operating flights and conducted sterilization. Quang Ninh Province People's Committee decided to lockdown Cai Rong for 21 days from 30 January after it registered infections linked to this cluster.

• Dong Trieu town cluster: appeared a little later on 28 January. The leader of Quang Ninh province said, after the detection of a community infection in Dong Trieu town, they established a Quick Response Task Force, which mobilized 500 medical staff and students from medical schools to prevent the pandemic. The authorities traced 5,091 contacts and took 721 samples, 3 samples are positive. On 3 February, the town were locked down to contain the virus.[168] By the end of 6 February, a total of 48 people in Quang Ninh were reported to have COVID-19, the authorities have been traced over 100,000 people had epidemiological factors with COVID-19 patients and tested nearly 33,100 people.[169]

• POYUN company cluster: Is the largest cluster. Of all 290 confirmed cases in the province, at least 280 are linked here.[170] By the morning of January 29, Hai Duong had collected a total of 1,936 samples at the company. The authorities of Chi Linh City moved more than 2,000 workers who are in quarantine at the company to six quarantine locations around the city.[171]

• Tan Son Nhat International Airport cluster: On 6 February, HCDC detected two new positive cases are cargo handler at Tan Son Nhat airport and his brother, both of these cases were not related to an outbreak in Hai Duong. After received information, Binh Duong province's government quarantined an apartment where they live with more than 3,000 people in Vinh Phu ward, Thuan An city.[172] Two days later, during tracing process, the authorities found that four of his colleagues and 25 of their close contacts live in Ma Lang - the largest slum in the city and six other districts, were tested positive for coronavirus.[173]

In just one week after third wave began, Vietnam recorded 398 cases in community in 12 cities and provinces. According to WHO, a total of more than 10,9 million people have been placed under quarantine since the beginning of the pandemic.[174]