Between 11th–25th June 2021, 69 healthcare workers were tested positive for SARS-CoV-2. 23 complete genome sequences were obtained. Viral loads of breakthrough Delta variant infection cases were 251 times higher than those of cases infected with old strains detected between March-April 2020.
The 23 complete genome sequences all belonged to the Delta variant, and were phylogenetically distinct from the contemporary Delta variant sequences obtained from community transmission cases, suggestive of ongoing transmission between the workers.
Time from diagnosis to PCR negative was 8–33 days (median: 21). Neutralizing antibody levels after vaccination and at diagnosis of the cases were lower than those in the matched uninfected controls. There was no correlation between vaccine-induced neutralizing antibody levels and viral loads or the development of symptoms.
Interpretation: Breakthrough Delta variant infections are associated with high viral loads, prolonged PCR positivity, and low levels of vaccine-induced neutralizing antibodies, explaining the transmission between the vaccinated people. Physical distancing measures remain critical to reduce SARS-CoV-2 Delta variant transmission.
“The pressure to treat Covid-19 patients is too large and too heavy”. More than 6,000 Covid patients are being treated at 107 medical facilities [in Vietnam], of which 37 are critical and 11 are ECMO interventions, putting pressure on the treatment system.
According to the Subcommittee on Treatment, the Ministry of Health, by the afternoon of June 9, more than 6,000 Covid-19 cases were being treated, the largest number of patients ever, of which more than half were in Bac Giang with more than 4,000 cases. Next is Bac Ninh, Ho Chi Minh City and Hanoi.
Among the patients, 97 had severe prognosis, 125 severe cases required oxygen, 43 severe cases required non-invasive ventilation, 26 critical cases required invasive ventilation; and 11 critical cases requiring ECMO (extracorporeal circulation).
VNExpress.com report (in Vietnamese)
“There is no new hybrid variant in Vietnam at this moment based on WHO definition,” Kidong Park, the WHO representative in Vietnam, told Nikkei Asia on Wednesday. “The variant detected is Delta variant (B.1.617.2), with additional mutations, and needs more observation. We need to monitor during next couple of weeks,”
“This is within the existing [Delta] variant. It is an additional mutation” Park explained, adding “as for now, there is no alarming alert from WHO. Park also stressed the Delta variant is dangerous as it is highly contagious and spreads very quickly.
Bac Giang province will move all 4,000 workers and people at the Covid-19 outbreak in Nui Hieu village, Quang Chau commune, Viet Yen district, to concentrated isolation. On the evening of June 2, Vice Chairman of Bac Giang Provincial People’s Committee, said that after moving all people out of Nui Hieu village, the government will disinfect and clean the environment. People in the village after finishing 21 days of concentrated isolation will be tested and ensure safety before returning to the area. It is expected that a part of workers will be moved out of the village from tomorrow 3rd June 2021 and continue in the following days.
Previously, from the end of May, Bac Giang transferred 3,000 workers in Nui Hieu village to districts and cities concentrated isolation and more than 2,300 workers quarantine at military facilities.
Deputy Director of the Medical Examination and Treatment Administration, Vietnamese Ministry of Health, assessed that young people without underlying diseases develop lung damage very quickly, just a few days after symptoms appear white on both sides of the lungs.
“Especially in this epidemic, the clinical manifestations of patients are different from the previous epidemic with mutations. Specifically, even young people without underlying diseases, lung damage is also very rapid, often occurs from the 7th to the 10th day, as soon as symptoms appear, after a few days, white blur appears on both sides of the lungs, “said Khoa. “Therefore, the risk of death may be in age groups, not only in the elderly and those with underlying diseases. Therefore, the treatment work also requires posing the problem of coping, responding to possible situations”.
VNExpress.net report (in Vietnamese)
Vietnam has detected a coronavirus hybrid variant with characteristics from the existing B16172 Delta variant and B117 Alpha variant, the Ministry of Health announced Saturday. Minister Nguyen Thanh Long said a new coronavirus variant has recently been detected in Vietnam with characteristics from both the Alpha and the Delta variants. More specifically, it is a Delta variant B.1.617.2 with mutations that originally belong to the Alpha variant B.1.1.7.
Laboratory cultures of the new variant, which is much more transmissible than the previously known types, revealed that the virus replicated itself very quickly, explaining why so many new cases appeared in different locations in a short period, Long was quoted as saying.
According to the Central Institute of Hygiene and Epidemiology, the results of viral gene sequencing of 32 Covid-19 patient samples, detected 4 samples infected with the Delta B16172 strain but carrying a gene mutation of the Alpha B117 strain.
“We found that there is a Y144 deletion mutation on the S protein of the virus B.1.617.2 (first detected in India). This mutation is similar to the mutation detected on variant B.1.1.7 (first detected in the UK)”, Professor Le Thi Quynh Mai, Deputy Director of the Central Institute of Hygiene and Epidemiology, said on the evening of May 29.
Up to now, Vietnam has recorded a total of 7 strains of nCoV, including: B.1.222, B.1.619, D614G, B.1.1.7 (Alpha variant), B.1.351, A.23.1 and B.1.617.2 (Delta variant).
The Covid-19 research team of the Ho Chi Minh City Hospital for Tropical Diseases has just conducted rapid decoding of the genome of SARS-CoV-2 from patient 4514. This is a resident Covid-19 case, living in Thu Duc city, Ho Chi Minh City was recorded on May 18 and officially announced this morning by the Ministry of Health on May 19.
Dr. Nguyen Van Vinh Chau, Director of Ho Chi Minh City Hospital for Tropical Diseases – representative of the research team, said that the team used an RNA sample extracted from the oropharyngeal swab of patient 4514 on May 18, performed gene sequencing using Illumina MiSeq and MinION techniques, with Genious genome assembly software.
The results of identification by Pangolin software show that the obtained genome belongs to the B.1.617.2 variant. The results of mutation identification by COV-GLUE showed that the genome carried 6 typical aminoacid mutations (T19R, L452R, T478K, D614G, P681R, D950N) and a deletion mutation (156-158) on the protein region. spikes of the mutant B.1.617.2.
This leads to the conclusion: Patient 4514 is infected with a variant B.1.617.2 similar to the one causing epidemics in some places in the North.
Variant B.1.617.2 is one of three sub-branches of strain B.1.617 from India. According to TS-BS Nguyen Van Vinh Chau, this strain B.1.617.2 carries a double mutation of L452R and T478K. The T478K mutation is also expected to specifically affect the affinity of the spike protein for the ACE2 receptor and make it easier for the virus to rapidly enter cells.
Vietnam has been left relatively unscathed by the Covid-19 pandemic so far as can be seen below
Wuhan, capital of Central China’s Hubei Province, has launched an epidemiological investigation after the coronavirus was discovered on two packages of beef imported from Brazil and on one package of fish imported from Vietnam, local health authority announced on Saturday.
None of the products were distributed to the market, local authority noted.
The samples were discovered among imported Brazilian beef in a warehouse freezer in the Donghu New Area district and on imported Vietnamese bass in another warehouse freezer in the Jiang’an district, according to local authority.