How R&D intensive firms react to the COVID-19 pandemic: Evidence from a quasi-natural experiment.

Prior research suggests that R&D intensive firms are especially vulnerable during crises due to their narrow specialization, high adjustment costs, increased distress risks, and higher sensitivity to financial distress. This paper exploits the difference in the research and development intensity as a quasi-natural experiment to examine the impact of the coronavirus pandemic on firm performance. Our study finds that the adverse consequences of COVID-19 on firms' profitability have been less pronounced for R&D intensive firms. R&D intensive firms are also able to record more positive changes in cash holdings as a response to the COVID-19 pandemic. As a result, R&D intensive firms are less likely to rely on external financing and record a lower level of increase in financing. Our results further highlight the potential function of R&D investment as a panacea for firm's growth during economic downturns.

Prevalence of and factors associated with diabetes mellitus among people living with HIV in Vietnam.

Studies have shown that people living with HIV (PLWH) have a higher risk of having non-communicable diseases (NCDs) than do people without HIV. In Vietnam, HIV remains a major public health concern, and with recent rapid economic growth, NCDs such as diabetes mellitus (DM) have become a significant disease burden. This cross-sectional study was conducted to examine the prevalence of DM and the factors associated with DM among PLWH on antiretroviral therapy (ART). In total, 1,212 PLWH were included in the study. The age-standardized prevalence of DM and pre-diabetes were 9.29% and 10.32%, respectively. In the multivariate logistic regression analysis, male sex, age above 50 years, and body mass index ≥ 25 kg/m2 were associated with DM, and borderline p-value was found for associations with current smoking and years on ART. The results suggest higher DM prevalence among PLWH and that longer time on ART could be an important risk factor for DM among PLWH. These findings also suggest that interventions such as weight control and smoking cessation support could be provided at outpatient clinics. Integration of HIV/AIDS and NCDs services is essential to address health needs comprehensively and enhance health-related quality of life for PLWH.

Possible association of HLA-DP polymorphism and antiretroviral therapy with hepatitis B virus clearance in an HIV-infected Vietnamese population.

There is little evidence regarding the association between hepatitis B virus (HBV) chronicity and HLA-DP among the HIV-infected Vietnamese population. To study this, we conducted a cross-sectional analysis and a prospective study involving an HIV-infected Vietnamese cohort. The association between HBV chronicity and HLA-DP single nucleotide polymorphisms (SNPs) of rs3077 and rs9277535 among Vietnamese patients with previous HBV exposure was first evaluated. In addition, treatment-naive patients with chronic HBV infection were followed between 2012 and 2017 for HBV clearance after the initiation of antiretroviral therapy (ART). A total of 820 subjects with previous HBV exposure were included in the cross-sectional study. Among them, 147 (17.9 %) had chronic HBV infection, and 673 (82.1 %) achieved HBV clearance. The proportions of minor allele homozygotes of rs3077 and rs9277535 were 10.9 % and 15.2 % (p = 0.481) and 4.1 % and 11.7 % (p = 0.003), respectively. Multivariate analysis showed that rs9277535 minor homozygote was a significant protective factor against chronic HBV infection (odds ratio [OR], 0.271; 95 % confidence interval [CI]; 0.114-0.642, p = 0.001). Further, none of the 43 patients in the prospective study, who received ART possessed the rs9277535 minor homozygote. The average follow-up period was 4.8 years, and 10 subjects (23.3 %, 4.9 %/person-years) achieved HBV clearance. Univariate analysis revealed that the SNPs were not significantly associated with HBV clearance. In conclusion, our study confirmed that the rs9277535 minor allele homozygote was significantly associated with HBV clearance among HIV-infected Vietnamese patients.

HLA Class I-Mediated HIV-1 Control in Vietnamese Infected with HIV-1 Subtype A/E.

HIV-1-specific cytotoxic T cells (CTLs) play an important role in the control of HIV-1 subtype B or C infection. However, the role of CTLs in HIV-1 subtype A/E infection still remains unclear. Here we investigated the association of HLA class I alleles with clinical outcomes in treatment-naive Vietnamese infected with subtype A/E virus. We found that HLA-C*12:02 was significantly associated with lower plasma viral loads (pVL) and higher CD4 counts and that the HLA-A*29:01-B*07:05-C*15:05 haplotype was significantly associated with higher pVL and lower CD4 counts than those for individuals without these respective genotypes. Nine Pol and three Nef mutations were associated with at least one HLA allele in the HLA-A*29:01-B*07:05-C*15:05 haplotype, with a strong negative correlation between the number of HLA-associated Pol mutations and CD4 count as well as a positive correlation with pVL for individuals with these HLA alleles. The results suggest that the accumulation of mutations selected by CTLs restricted by these HLA alleles affects HIV control.IMPORTANCE Most previous studies on HLA association with disease progression after HIV-1 infection have been performed on cohorts infected with HIV-1 subtypes B and C, whereas few such population-based studies have been reported for cohorts infected with the Asian subtype A/E virus. In this study, we analyzed the association of HLA class I alleles with clinical outcomes for 536 HIV-1 subtype A/E-infected Vietnamese individuals. We found that HLA-C*12:02 is protective, while the HLA haplotype HLA-A*29:01-B*07:05-C*15:05 is deleterious. The individuals with HIV-1 mutations associated with at least one of the HLA alleles in the deleterious HLA haplotype had higher plasma viral loads and lower CD4 counts than those of individuals without the mutations, suggesting that viral adaptation and escape from HLA-mediated immune control occurred. The present study identifies a protective allele and a deleterious haplotype for HIV-1 subtype A/E infection which are different from those identified for cohorts infected with HIV-1 subtypes B and C.

A strong association of human leukocyte antigen-associated Pol and Gag mutations with clinical parameters in HIV-1 subtype A/E infection.

OBJECTIVES: Identification of human leukocyte antigen-associated HIV-1 polymorphisms (HLA-APs) in different global populations furthers our understanding of HIV-1 pathogenesis and may help identify candidate immunogens for HIV vaccines targeted to these populations. Although numerous population-based studies identifying HLA-APs have been conducted in HIV-1 subtype B- and subtype C-infected cohorts, few have focused on subtype A/E. DESIGN: We investigated HLA-APs in a cohort of chronically HIV-1 subtype A/E-infected Vietnamese individuals. METHODS: HLA-APs in HIV-1 Gag, Pol, and Nef regions from 388 treatment-naive individuals chronically infected with HIV-1 subtype A/E were analyzed using phylogenetically informed approaches. RESULTS: A total of 303 HLA-APs were identified. HLA-APs occurring at six positions in Gag and six positions in Pol were significantly associated with higher plasma viral load (pVL), whereas HLA-APs occurring at two positions in Gag and 13 positions in Pol were significantly associated with lower CD4 T-cell counts. Furthermore, the proportion of Pol codons harboring an HLA-AP specific to the host's HLA correlated positively with HIV-1 pVL (R = 0.22; P < 0.0001) and inversely with CD4 T-cell counts (R = -0.32; P < 0.0001). Similarly, the proportion of HLA-associated Gag codons harboring host-specific HLA-AP correlated inversely with CD4 T-cell counts (R = -0.13; P = 0.01). CONCLUSION: These significant associations between HIV-1 amino acids adapted to Vietnamese HLA alleles and higher pVL and lower CD4 T-cell counts suggests that accumulation of cytotoxic T cells escape mutations may influence clinical outcomes in HIV-1 subtype A/E-infected Vietnamese individuals.