Presence of Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) Antibodies Among Vietnamese Healthcare Workers by Dosing Interval for ChAdOx1 nCoV-19 Vaccine.

BACKGROUND: Before the SARS-CoV-2 Delta variant arrived in Vietnam, case rates suggested seroprevalence of SARS-CoV-2 was low. Beginning in March 2021, we assessed different dosing schedules and adverse events following immunization (AEFIs) for ChAdOx1 nCoV-19 vaccine among healthcare workers (HCWs). METHODS: We performed a prospective cohort study to estimate the prevalence of IgG antibodies to SARS-CoV-2 before and after ChAdOx1 nCoV-19 vaccination. We conducted antibody testing among HCWs in February 2021 (baseline), before the second dose (June-July 2021), and 1 and 3 months after the second dose. We detected antibodies to SARS-CoV-2 using Tetracore® FlexImmArray™, and surrogate neutralizing antibodies using GenScript cPass™. Neither assay can distinguish natural from vaccine-induced antibodies. We assessed AEFIs through interview post-dose 1 and 1 month post-dose 2. RESULTS: Before vaccination, 1/617 participants (0.16%) had antibodies to SARS-CoV-2. Of these 617, 405 were vaccinated with ChAdOx1 nCoV-19 with 4-8- (60%), 9-12- (27%), or ≥13-week (13%) intervals between the 2 doses. Three months following series completion, 99% and 97% of vaccinated participants had ≥1 sample with detectable antibodies and surrogate neutralizing antibodies against SARS-CoV-2, respectively. We observed no significant differences among those with different dosing intervals at last follow-up. All participants reported PCR testing for SARS-CoV-2 during the study; 2 (0.5%) were laboratory-confirmed. AEFIs were more frequent post-dose 1 (81%) vs post-dose 2 (21%). CONCLUSIONS: In this population, regardless of dosing interval, ChAdOx1 nCoV-19 induced antibodies within 3 months of the second dose. These findings may offer flexibility to policymakers when balancing programmatic considerations with vaccine effectiveness.

Evaluation of Vietnam's post-exposure prophylaxis delivery system, 2017.

BACKGROUND: Canine-mediated human rabies deaths typically occur in poor and rural populations with limited access to rabies biologics: vaccine and immunoglobulin. A critical aspect of reducing rabies deaths is understanding how these countries procure, deliver, and forecast rabies biologics. Vietnam is one of the few endemic countries where biologics is widely available. However, a formal evaluation of its current rabies biologics distribution system has not been conducted. METHODS: In 2017, we conducted a formal evaluation of Vietnam's rabies biologics distribution system. Our goals were (1) to identify centers providing rabies biologics (2) identify costs to the patient and centers and (3) assess the rabies biologic procurement and delivery system at eligible district and provincial centers (provides and orders biologics for itself and other centers directly from the manufacture). To conduct the formal evaluation, we developed a standardized survey that was distributed to centers. RESULTS: Of the 780 designated rabies biologics centers in Vietnam, 659 (84%) of them provide rabies immunoglobulin (eRIG), vaccine, or both. Of the 177 eligible centers, 90% (160) responded to the survey. The average costs to patients were $8.45 (range: 5.43-12.77) for one dose of IM injection, $13.90 (range: 11.86-16.71) for domestic eRIG, and $23 (21.11-27.11) for imported eRIG. Respondents reported experiencing delays in receiving vaccine in 50 centers and eRIG in 14 centers within the past year. Respondents stated their top three challenges in providing biologics were: delays or shortages from manufactures, lack of funds to pay for biologics, and the high cost of biologics. CONCLUSIONS AND RELEVANCE: Despite the wide availability of biologics in Vietnam, more work is needed to provide affordable and reliable supply of biologics to patients. This includes the expansion of ID injection use throughout the country to lower vaccine demand, and decrease the costs to centers and patients. Furthermore, a more coordinated effort to share biologics among centers, possibly through a more centralized system at the provincial level may alleviate delays and shortages.

Rabies post-exposure prophylaxis initiation and adherence among patients in Vietnam, 2014-2016.

BACKGROUND: Adhering to post-exposure prophylaxis (PEP): wound treatment, vaccine, and rabies immunoglobulin (RIG) is a crucial step in preventing rabies mortality. When PEP is widely available, a lack of adherence to the recommended treatment guidelines can also lead to death. Our objective was to understand characteristics associated with adherence to the vaccine regimen and RIG in Vietnam. METHODS: We obtained individual-level data on PEP adherence from registries at 10 sites located in five provinces. From these registries, we extracted epidemiologic characteristics of patients including the timing of PEP initiation and completion. We used descriptive analyses and logistic regression to examine patient characteristics associated with initiation and completion of RIG and vaccine. Based on reported rabies mortality, the government defined provincial rabies burden as medium-burden (<5 and >2 deaths) and high-burden (≥5 deaths). RESULTS: During 2014-2016, 15,646 patients received PEP in our study. Among 14,296 vaccinated patients, only 41.4% (5847) completed their five-dose intramuscular (IM) injections and 81.6% (133) of patients completed their eight-dose intradermal (ID) injections. Approximately 26% of patients received RIG. Patient characteristics associated with vaccine completion were females (44%), <15 years of age (44%), category 1 exposure (68%, bite location on leg (46%), bite from bat (56%), bite from a healthy animal (45%), high-burden province (86%), and district preventive center (49%). Disparities were revealed among provinces, with high-burden provinces having highest (86%) and lowest (7%) vaccine completion rates. CONCLUSIONS AND RELEVANCE: Vietnam has made tremendous progress towards reducing the burden of rabies. However, despite the wide availability of PEP, we found relatively low rates of vaccine completion. Our findings suggest provider training and patient education is needed to ensure appropriate treatment is completed. Moreover, our data suggest changes to information reported through the national surveillance system for monitoring good clinical practice for rabies prevention and control.

Rabies Vaccine Hesitancy and Deaths Among Pregnant and Breastfeeding Women - Vietnam, 2015-2016.

Human rabies deaths are preventable through prompt administration of postexposure prophylaxis (PEP) with rabies immune globulin and rabies vaccine after exposure to a rabid animal (1); there are no known contraindications to receiving PEP (1,2). Despite widespread availability of PEP in Vietnam, in 2015 the Ministry of Health (MoH) received reports of pregnant and breastfeeding women with clinically diagnosed rabies. MoH investigated factors associated with these rabies cases. MoH found that, during 2015-2016, among 169 cases reported in Vietnam, two probable cases of rabies were reported in breastfeeding mothers and four in pregnant women, all of whom had been bitten by dogs. All six patients died. Three of the four pregnant women had cesarean deliveries. One of the three newborns died from complications believed to be unrelated to rabies; the fourth pregnant woman contracted rabies too early in pregnancy for the fetus to be viable. Two of the patients sought care from a medical provider or traditional healer; however, none sought PEP after being bitten. In each case, families reported the patient's fear of risk to the fetus or breastfed child as the primary barrier to receiving PEP. These findings highlight the need for public health messaging about the safety and effectiveness of PEP in preventing rabies among all persons with exposures, including pregnant and breastfeeding women.

A dataset on tail risk of commodities markets.

This article contains the datasets related to the research article "The long and short of commodity tails and their relationship to Asian equity markets"(Powell et al., 2017) [1]. The datasets contain the daily prices (and price movements) of 24 different commodities decomposed from the S&P GSCI index and the daily prices (and price movements) of three share market indices including World, Asia, and South East Asia for the period 2004-2015. Then, the dataset is divided into annual periods, showing the worst 5% of price movements for each year. The datasets are convenient to examine the tail risk of different commodities as measured by Conditional Value at Risk (CVaR) as well as their changes over periods. The datasets can also be used to investigate the association between commodity markets and share markets.