An Immunobridging Study to Evaluate the Neutralizing Antibody Titer in Adults Immunized with Two Doses of Either ChAdOx1-nCov-19 (AstraZeneca) or MVC-COV1901.

Rapid development and deployment of vaccines is crucial to control the continuously evolving COVID-19 pandemic. The placebo-controlled phase 3 efficacy trial is still the standard for authorizing vaccines in the majority of the world. However, due to a lack of eligible participants in parts of the world, this has not always been feasible. Recently, the Taiwan Food and Drug Administration, following the consensus of the International Coalition of Medicines Regulatory Authorities (ICMRA), adopted the use of immunobridging studies as acceptable for authorizing COVID-19 vaccines in lieu of efficacy data. Here, we describe a study in which our candidate vaccine, MVC-COV1901, an adjuvanted protein subunit vaccine, has been granted emergency use authorization (EUA) in Taiwan based on a noninferiority immunobridging study. Immunogenicity results from the per protocol immunogenicity (PPI) subset (n = 903) from the MVC-COV1901 phase 2 trial were compared with results from 200 subjects who had received an adenovirus vector vaccine, AstraZeneca ChAdOx nCOV-19 (AZD1222), in a separate study. The lower bound of the 95% confidence interval (CI) of the geometric mean titer (GMT) ratio comparing MVC-COV1901 to AZD1222 was 3.4. The lower bound of the 95% CI of the sero-response rate was 95.5%. Both the GMT ratio and sero-response rate exceeded the criteria established by the Taiwan regulatory authority, leading to EUA approval of MVC-COV1901 in Taiwan.

Incidence and Risk Factors of Reinfection with HCV after Treatment in People Living with HIV.

Infection with hepatitis C virus (HCV) does not induce protective immunity, and re-exposure to HCV can reinfect the population engaging in high-risk behavior. An increasing incidence of acute hepatitis C infection in people living with HIV (PLWH) has been described in recent years. This retrospective cohort study was conducted in PLWH who completed HCV therapy between June 2009 and June 2020 at an HIV care hospital, to analyze their basic characteristics and risky behavior. Of 2419 patients, 639 were diagnosed with HCV infection and 516 completed the HCV therapy with a sustained virologic response. In total, 59 patients (11.4%) were reinfected with acute hepatitis C, and the median time to reinfection was 85.3 weeks (IQR: 57-150). The incidence of reinfection was 6.7 cases/100 person-years. The factors associated with reinfection were being male (AHR, 8.02; 95% CI 1.08-59.49), DAA (direct-acting antiviral) treatment (AHR, 2.23; 95% CI 1.04-4.79), liver cirrhosis (AHR, 3.94; 95% CI 1.09-14.22), heroin dependency (AHR: 7.41; 95% CI 3.37-14.3), and HIV viral loads <50 copies/mL at the follow-up (AHR: 0.47, 95% CI 0.24-0.93) in the subgroup of people who inject drugs (PWID). Amphetamine abuse (AHR: 20.17; 95% CI 2.36-172.52) was the dominant factor in the subgroup of men who have sex with men (MSM). Our study suggests that education and behavioral interventions are needed in this population to prevent reinfection.

Grazoprevir/elbasvir in peginterferon alfa plus ribavirin experienced patients with chronic genotype 1 HCV/HIV co-infection: a non-randomized, open-label clinical trial.

Background and aims: We aimed to evaluate the efficacy and tolerability of grazoprevir/elbasvir in patients with chronic genotype 1 hepatitis C virus (HCV) and HIV co-infection who experienced peginterferon alfa plus ribavirin (PegIFN/RBV) (clinicaltrials.gov NCT03098121). Methods: This non-randomized, open-label trial study was conducted in Taoyuan General Hospital. HIV-infected patients were screened for HCV antibody since June 1, 2012, and HCV and HIV co-infected patients were tested for HCV RNA. The subjects who experienced PegIFN/RBV were enrolled in the study, and of whom with chronic genotype 1a or 1b received grazoprevir 100 mg and elbasvir 50 mg in a fixed-dose combination tablet once daily with or without ribavirin for 12 to 16 weeks. Results: Of 2,419 HIV-infected patients, 40 patients with chronic genotype 1 HCV and HIV co-infection who failed PegIFN/RBV treatment were enrolled. Sixteen patients had genotype 1a and 24 patients had genotype 1b, with or without cirrhosis. The median age was 42 (41-47) years, and 5 patients (12.5%) were diagnosed with liver cirrhosis (child Pugh score A). The median CD4 count was 504 cells/µL (321-689). All patients (100%) had HIV viral load <200 copies/mL, and HCV viral load was 6.3 log10 IU/mL (3.98-7.12). At the end of treatment, all patients (100%, 40/40) had undetectable HCV viral load, and 95.0% (38/40) of patients achieved sustained virologic response at 12 weeks. Conclusion: Grazoprevir/elbasvir was effective in genotype 1 patients co-infected with HIV with or without cirrhosis. This finding is consistent with that of previous trials of this regimen in monoinfected population.

Tenofovir disoproxil fumarate-associated hypophosphatemia as determined by fractional excretion of filtered phosphate in HIV-infected patients.

INTRODUCTION: Tenofovir disoproxil fumarate (TDF) -containing regimens have been associated with nephrotoxicity and hypophosphatemia in HIV-infected patients. The objective of this study was to assess the possible risk factors for hypophosphatemia and evaluate the relationship between fractional excretion of filtered phosphate (FePi) and hypophosphatemia in TDF users. PATIENT AND METHODS: Patients were enrolled in a prospective cohort study between January 2011 and December 2014. We classified experienced HIV-infected patients (individuals maintained on antiretroviral therapy (ART) for 6 months or more) and naïve patients into 3 treatment groups: TDF-containing ART (group 1), non-TDF-containing ART (never received TDF or had not received TDF in the past 6 months; group 2) and naive to antiretroviral therapy (group 3). Specimens from each individual were assessed for serum phosphate, serum creatinine, urine phosphate, and urine creatinine. Multivariable logistic regression was performed to control for the following variables measured at baseline: eGFR, age, sex, sexual orientation, injection drug use (IDUs), HIV-RNA viral load, and CD4 cell count. RESULTS: The frequency of hypophosphatemia in groups 1, 2, and 3 was 20.2%, 7.2%, and 14.6%, respectively (P = 0.002). FePi above 10% also was significantly associated with hypophosphatemia (P = 0.003; adjusted odds ratio = 2.54). Patients with elevated CD4 cell counts (>500 cells/µL) exhibited a lower risk of hypophosphatemia (P = 0.002; adjusted odds ratio = 0.35). CONCLUSIONS: Hypophosphatemia is a multifactorial etiology; FePi was confirmed as a suggested method to predict the risk of hypophosphatemia in TDF users. Clinical Trial Number: TYGH103011.