ABSTRACT
BackgroundNanocovax is a recombinant severe acute respiratory syndrome coronavirus 2 subunit vaccine composed of full-length prefusion stabilized recombinant SARS-CoV-2 spike glycoproteins (S-2P) and aluminum hydroxide adjuvant. In a Phase 1 and 2 studies, (NCT04683484) the vaccine was found to be safe and induce a robust immune response in healthy adult participants. MethodsWe conducted a multicenter, randomized, double-blind, placebo-controlled study to evaluate the safety, immunogenicity, and protective efficacy of the Nanocovax vaccine against Covid-19 in approximately 13,007 volunteers aged 18 years and over. The immunogenicity was assessed based on Anti-S IgG antibody response, surrogate virus neutralization, wild-type SARS-CoV-2 neutralization and the types of helper T-cell response by intracellular staining (ICS) for interferon gamma (IFNg) and interleukin-4 (IL-4). The vaccine efficacy (VE) was calculated basing on serologically confirmed cases of Covid-19. FindingsUp to day 180, incidences of solicited and unsolicited adverse events (AE) were similar between vaccine and placebo groups. 100 serious adverse events (SAE) were observed in both vaccine and placebo groups (out of total 13007 participants). 96 out of these 100 SAEs were determined to be unrelated to the investigational products. 4 SAEs were possibly related, as determined by the Data and Safety Monitoring Board (DSMB) and investigators. Reactogenicity was absent or mild in the majority of participants and of short duration. These findings highlight the excellent safety profile of Nanocovax. Regarding immunogenicity, Nanocovax induced robust IgG and neutralizing antibody responses. Importantly, Anti S-IgG levels and neutralizing antibody titers on day 42 were higher than those of natural infected cases. Nanocovax was found to induce Th2 polarization rather than Th1. Post-hoc analysis showed that the VE against symptomatic disease was 51.5% (95% confidence interval [CI] was [34.4%-64.1%]. VE against severe illness and death were 93.3% [62.2-98.1]. Notably, the dominant strain during the period of this study was Delta variant. InterpretationNanocovax 25 microgram (mcg) was found to be safe with the efficacy against symptomatic infection of Delta variant of 51.5%. FundingResearch was funded by Nanogen Pharmaceutical Biotechnology JSC., and the Ministry of Science and Technology of Vietnam; ClinicalTrials.gov number, NCT04922788.
ABSTRACT
BackgroundThere is a shortage of chemical reagents for severe acute respiratory syndrome - coronavirus 2 (SARS-CoV-2) diagnosis and a surge of SARS-CoV-2cases, especially in limited-resource settings. Therefore, the combination of an optimal assay kit is necessary. MethodsWe compared the ability to screen SARS-CoV-2 among three primer-probe sets in two different master mixes, Invitrogen SuperScript III One-Step RT-PCR and LightCycler Multiplex RNA Virus Master. ResultsThe assay with TIB-Molbiol, IDT, and Phu Sa sets for LightCycler Multiplex RNA Virus Master or Invitrogen SuperScript III One-Step RT-PCR showed positive results from a single reaction of triplicate in the three days of 4.8 copies per reaction. R-squared and amplification efficiency were 0.97 and ranged from 107 to 108%, respectively. ConclusionsOur findings indicated that TIB-Molbiol, IDT, and Phu Sa primer-probe sets could be beneficial for the laboratory screening of SARS-CoV-2 by RT-qPCR assay of E gene. There is a need to consider the combination of these reagent sets as a new strategy to increase the testing capacity of screening programs for COVID-19.
ABSTRACT
Objective@#To document the evolution and optimization of the Zika virus (ZIKV) disease surveillance system in southern Viet Nam in 2016 and to describe the characteristics of the identified ZIKV-positive cases.@*Methods@#We established a sentinel surveillance system to monitor ZIKV transmission in eight sites in eight provinces and expanded the system to 71 sites in 20 provinces in southern Viet Nam in 2016. Blood and urine samples from patients who met the case definition at the sentinel sites were tested for ZIKV using real-time reverse transcription polymerase chain reaction at the Pasteur Institute in Ho Chi Minh City (PI-HCMC). We conducted descriptive analysis and mapped the ZIKV-positive cases.@*Results@#In 2016, 2190 specimens from 20 provinces in southern Viet Nam were tested for ZIKV at PI-HCMC; 626 (28.6%), 484 (22.1%), 35 (1.6%) and 1045 (47.7%) tests were conducted in the first, second, third and fourth quarters of the year, respectively. Of these tested specimens, 214 (9.8%) were ZIKV positive with 212 (99.1%) identified in the fourth quarter. In the fourth quarter, the highest positivity rate was those in age groups 30–39 years (30.0%) and 40–59 years (31.6%). Of the 214 ZIKV-positive patients, 210 (98.1%) presented with rash, 194 (90.7%) with fever, 149 (69.6%) with muscle pain, 123 (57.5%) with joint pain and 66 (30.8%) with conjunctivitis.@*Discussion@#The surveillance system for ZIKV disease underwent several phases of optimization in 2016, guided by the most up-to-date local data. Here we demonstrate an adaptable surveillance system that detected ZIKV-positive cases in southern Viet Nam.
ABSTRACT
Background: Acute gastroenterophathy usually caused by the Rota virus for children under 5 years old. Objectives: To present various types of data on epidemiology of ROTA virus diarrhea in Ho Chi Minh city from 12/2006-11/2007. Material and method: The data were collected from 500 stool specimens of diarrhea diagnosed chilren hosptalised at Thuy Dien Pediatric hospital 1, Ho Chi Minh city from December/2006 to November /2007. Results:There were 322 rotavirus-positive specimens, representing 64.4%. The proportions of monthly distribution of cases with diarrhea due to rotavirus were 90.1%, 54.39%, 85.37%, 74.51%, 72.92%, 41.67%, 26.67%, 58.33%, 79.31%, 52.63%, 69.05% and 57.78%, respectively. The numbers of rotavirus-positive cases in male and female were 216 (65.26%) and 106 (62.72%), respectively. The proportions of Rota virus positive children compared to total number of diarrheal cases with age 0-3, 3-6, 6-12, 12-24, 24-36 and over 36 months were 2.80%, 7.76%, 40.06%, 40.68%, 5.28% and 3.42%, respectively.\r\n', u'The results of typing identification indicated that the phenotypes of 98 among 100 specimens were identified (98%) in which there were sixty-one specimens of G1P8 (61%), one specimen of G2P8 (1%), fourteen specimens of G3P8 (14%), four of specimens of G4P8 (4%), eighteen specimens of GmixedP8 (18%). There were only two specimens of GnontypeableP8 (2%). Conclusion: Further studies should be carried out to clear this issue.\r\n', u'
