We studied the development and persistence of neutralizing antibodies against SARS-CoV-2 ancestral strain, and Delta and Omicron (BA.1 and BA.2) variants in Vietnamese healthcare workers (HCWs) up to ...15 weeks after booster vaccination. We included 47 HCWs, including group 1 (G1, N = 21) and group 2 (G2; N = 26) without and with breakthrough Delta variant infection before booster immunization, respectively). The study participants had completed primary immunization with ChAdOx1-S and booster vaccination with BNT162b2. Neutralizing antibodies were measured using a surrogate virus neutralization assay. Of the 21 study participants in G1, neutralizing antibodies against ancestral strain, Delta variant, BA.1, and BA.2 were (almost) abolished at month 8 after the second dose, but all had detectable neutralizing antibodies to the study viruses at week 2 post booster dose. Of the 26 study participants in G2, neutralizing antibody levels to BA.1 and BA.2 were significantly higher than those to the corresponding viruses measured at week 2 post breakthrough infection and before the booster dose. At week 15 post booster vaccination, neutralizing antibodies to BA.1 and BA.2 dropped significantly, with more profound changes observed in those without breakthrough Delta variant infection. Booster vaccination enhanced neutralizing activities against ancestral strain and Delta variant compared with those induced by primary vaccination. These responses were maintained at high levels for at least 15 weeks. Our findings emphasize the importance of the first booster dose in producing cross-neutralizing antibodies against Omicron variant. A second booster to maintain long-term vaccine effectiveness against the currently circulating variants merits further research.
In Southeast Asia, climate change will potentially have negative consequences for urban transportation infrastructure (UTI). It is necessary to improve the understanding of climate change-associated ...loss and damage in relation to UTI to ensure the sustainability of existing transportation assets and for prioritizing future investments. However, there is currently limited knowledge on how to practically assess loss and damage for UTI in the context of climate change and then to incorporate appropriate adaptation measures and strategies to future-proof transportation planning. This study presents the results and experiences from assessing climate change-related loss and damage to UTI in six cities of Cambodia, Thailand and Vietnam. One pilot city from each country was selected for assessment by applying NK-GIAS software to determine loss and damage for urban roads. It was found that the six selected cities were highly vulnerable to climate change given their location and exposure to sea-level rise, storm surge, flooding, and salinity intrusion. Through analyses conducted using NK-GIAS software, economic losses for different flood scenarios were determined. The linkage between flooding and road damage was demonstrated, with maximum damage estimations under the most extreme flooding scenario of approximately 20 million USD for Hoi An, 3 million USD for Kampot and 21 million USD for Samut Sakhon, corresponding to water levels of 3.4 m, 4.0 m and 2.7 m respectively. Damage to the road network was identified as a key impact related to climate change. Further research is recommended to develop appropriate damage curves through laboratory analysis, addressing both flood depth and duration, to strengthen the NK-GIAS analyses undertaken in this study.
An evaluation of three new rapid diagnostic test kits for human immunodeficiency virus types 1 and 2 (HIV-1/2), hepatitis B surface antigen (HBsAg), and syphilis involved a two-phase comparison of ...rapid diagnostic assays using prospectively collected from hospitals and clinics in Ho Chi Minh City, Vietnam. After specificity and sensitivity testing, three new rapid diagnostic test kits were tested in parallel with six commonly used diagnostic test kits. The Determine HIV-1/2 test had fewer indeterminate or equivocal results than the Capillus HIV-1/HIV-2 or HIV Blot 2.2 tests. However, the Determine HIV-1/2 test yielded one false-positive result when compared with the Serodia HIV, HIV Blot 2.2, and microparticle enzyme immunoassay (IMx) HIV tests. The Serodia HBsAg test yielded more false-negative results when compared with the Determine HBsAg diagnostic test kit. The results of the syphilis diagnostic tests evaluated in this clinical trial consistently agreed with those of the rapid plasma reagin test for syphilis. The Determine Syphilis Treponema pallidum (TP) test had three false-positive results compared with the Serodia TP and the Serodia TP x particle agglutination (PA) tests, which had two false-positive results that were confirmed as negative by an ELISA. Application of these serologic tests within this comparative evaluation framework, using the World Health Organization alternative testing strategies, proved to be an effective way to determine serostatus related to HIV, hepatitis B, and syphilis.
With a population exceeding 630 million (8% of the global population), the ten member states of the Association of Southeast Asian Nations (ASEAN) accounted for approximately 61 million (7.9%) of ...global COVID-19 cases and 808 166 (11.6%) of deaths, with case fatality rate (CFR) of 1.3% by the end of 2023 1. The global response to the COVID-19 pandemic has highlighted the importance of collaborative networks within ASEAN, particularly in scientific information, technology and research exchange, resource mobilisation, and capacity building. In response to COVID-19, ASEAN launched several initiatives, including the ASEAN Comprehensive Recovery Framework (ACRF) 2, the ASEAN Travel Corridor Arrangement Framework, the ASEAN COVID-19 Response Fund, and the activation of the ASEAN Coordinate Council Working Group on Public Health Emergencies (ACCWG PHE) 3. The ASSeSS Working Group has identified a few key areas of partnership to mitigate the effects of COVID-19 pandemic crises and prepare for future pandemics: – enhance disease surveillance for early outbreak detection; – establish and harmonise research tools such as virus, serum or cell line banks that will enable the rapid assessment of transmission dynamics and population susceptibility to emerging pathogens in the future; – accelerate local medical diagnostics and equipment development with pilot production, quality assurance, regulatory clearance and scale-ups; – adopt One Health and Planetary Health approaches to address human threats related to animals, climate, and the environment; – establish formal and informal scientific networks for information and knowledge sharing to enable rapid response to outbreaks before they escalate into pandemics; – collaborative funding to support efforts in pandemic preparedness, for example, a revolving fund for vaccine development and procurement for the ASEAN region could be established by fostering public and private collaborations 10.
Thuy CTT, Ha CD, Long TD, Hai TV, Long ST, Chi TT, Quyen TTH, Yen VH, Khanh NTM, Trung NQ, Trung NT. 2023. Genetic variation within the coat color gene of Melanocortin 1Receptor (MC1R) in Mong Cai ...pigs of Vietnam. Biodiversitas 24: 1735-1741. Pig (Sus scrofa) is considered one of the major domesticated animals in Vietnam. Various indigenous pig varieties have been successfully developed as the Vietnamese's main daily meat source. However, little information has been reported about the conservation of these indigenous pig varieties. In this study,the Mong Cai, a prized domestic pig breed in Vietnam, is well-characterized by a black saddle on the hips extending to the lower abdomen. As a result of the introduction of exotic breeds and crossbreeding, Mong Cai pigs exhibited various phenotypic characteristics and coat colors. We constructed a database of Melanocortin 1Receptor(MC1R) coding sequences, including the MC1Rsequences of 26 Mong Cai and 20 other pig breeds from Europe and Asia. Subsequently, 12 haplotypes were determined using 18 mutations in 46 individuals. The phylogenetic tree result indicated that the Mong Cai population was distributed into two distinct haplotypes. Moreover, Mong Cai pigs could belong to the Asian clade; however, six Mong Cai individuals formed a distinct cluster. These six individuals carried the nt729G gene, which is prevalent in European pigs. In addition, our study could provide a solid foundation for further investigation of the evolution of indigenous pig varieties in Vietnam.
Objective:
Cinnamic acid and its derivatives have a numerous potential applications in many different fields such as pharmacy, organic “building blocks”, and corrosion inhibitors.
Method:
It is ...well-known that Verley-Doebner modification is a high efficient method for the preparation of cinnamic acid derivaties, especially with the compounds containing electron-donating subtituents at para position in aromatic ring. In this paper, 4-ethoxy-cinnamic acid was synthesized according to Verley-Doebner reaction with the use of pyrine acting as catalyst and solvent. The effect of the β-alanine concentration on the conversion of the starting material of 4-ethoxy-benzaldehyde was thoroughly investigated using high performance liquid chromatography. The results showed that consuming of 8% of β-alanine would convert 100% of 4-ethoxy-benzaldehyde to 4-ethoxy-cinnamic acid.
Result:
The structure of the obtained 4-ethoxy-cinnamic acid was also confirmed using Fourier transform infrared spectroscopy, Raman spectroscopy, and Gas chromatography-Mass spectroscopy.
Cinnamic acid and its derivatives have numerous potential applications in many different fields such as pharmacy, organic “building blocks”, and corrosion inhibitors. It is well-known that Verley-Doebner modification is a high efficient method for the preparation of cinnamic acid derivaties, especially with the compounds containing electron-donating subtituents at para position in aromatic ring. In this paper, 4-ethoxy-cinnamic acid was synthesized according to Verley-Doebner reaction with the use of pyrine acting as catalyst and solvent. The effect of the β-alanine concentration on the conversion of the starting material of 4-ethoxy-benzaldehyde was thoroughly investigated using high performance liquid chromatography. The results showed that consuming 8% of β-alanine would convert 100% of 4-ethoxy-benzaldehyde to 4-ethoxy-cinnamic acid. The structure of the obtained 4-ethoxy-cinnamic acid was also confirmed using Fourier transform infrared spectroscopy, Raman spectroscopy, and Gas chromatography-Mass spectroscopy.
Shigellosis is a disease caused by bacteria belonging to
Shigella spp.
and is a leading cause of bacterial gastrointestinal infections in infants in unindustrialized countries. The
Shigellae
are ...dynamic and capable of rapid change when placed under selective pressure in a human population. Extended spectrum beta lactamases (ESBLs) are enzymes capable of degrading cephalosporins (a group of antimicrobial agents) and the genes that encode them are common in pathogenic
E. coli
and other related organisms in industrialized countries. In southern Vietnam, we have isolated multiple cephalosporin-resistant
Shigella
that express ESBLs. Furthermore, over two years these strains have replaced strains isolated from patients with shigellosis that cannot express ESBLs. Our work describes the genes responsible for this characteristic and we investigate one of the elements carrying one of these genes. These finding have implications for treatment of shigellosis and support the growing necessity for vaccine development. Our findings also may be pertinent for other countries undergoing a similar economic transition to Vietnam's and the corresponding effect on bacterial populations.
A hepatitis outbreak affecting primarily adults occurred in southwestern Vietnam, along the Hau river bordering Cambodia, in June and July 1994. One month after the outbreak, sera and epidemiologic ...information were collected from 150 subjects: 50 patient cases, 50 matched, healthy community controls, and 50 geographic controls living 50 km upriver. The prevalence of immunoglobulin G (IgG) to hepatitis E virus (HEV) was significantly (P < 0.001) higher (76%) among cases than among the matched (38%) and geographic (38%) control populations. Immunoglobulin M to HEV was detected by enzyme-linked immunosorbent assay and Western blot in 16% of sera collected from patients one month after the outbreak. Hepatitis E virus RNA was detected with the polymerase chain reaction in 6% of sera from patients; RNA was not detected in either control group. These results indicate that HEV was the etiologic agent responsible for the outbreak. Children were under-represented among clinical cases. River water served as the principal source for drinking and bathing among most (96%) of the case and control study populations. Boiling of drinking water was negatively associated (P < 0.05) with IgG anti-HEV seropositivity. Unusually heavy rainfall likely contributed to conditions that favored the outbreak. This is the first recognized outbreak of epidemic HEV transmission in Indo-China.
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