Participants Switching to Second-Line Antiretroviral Therapy with Susceptible Virus Display Inferior Adherence and Worse Outcomes: An Observational Analysis

Evidence on the impact of human immunodeficiency virus (HIV) drug resistance on regimens following treatment failure is varied and inconclusive. Differential medication adherence may explain this variation. We aimed to test the association between drug resistance at first-line antiretroviral therapy (ART) switch and adherence to and virologic failure on subsequent ART. We conducted a secondary analysis of data from an open-labeled randomized trial of second-line ART (ACTG A5234). ART susceptibility was determined from study entry plasma using the Stanford Drug Resistance database version 8.7. Adherence was measured with microelectronic monitors. Three adherence variables and rates of virologic failure (HIV-1 RNA ≥1000 copies/mL) on second-line ART were compared between participants with and without resistance at first-line ART failure. Of 214 participants switching to second-line ART with baseline resistance results, 113 (53%) were men, mean age was 39 years (standard deviation 10.3), and 37 (17%) had susceptible virus at study entry. Cumulative genotypic susceptibility score (cGSS) was inversely associated with adherence, adjusted odds ratio (aOR) 0.15, 95% confidence interval (CI) (0.05-0.40), p < 0.001. The aOR of virologic failure for a one-unit increase in cGSS was 1.72, 95% CI (1.22-2.41), p < 0.001. Participants switched to second-line ART without resistance displayed inferior adherence and had higher rates of virologic failure. Therefore, these individuals warrant additional adherence interventions to help them achieve virologic success. Clinical Trial Registration number: NCT00608569.

Genome Characterization of Yellow Fever Virus Wild-Type Strain Asibi, Parent to Live-Attenuated 17D Vaccine, from Three Different Sources

The yellow fever virus vaccine, 17D, was derived through the serial passage of the wild-type (WT) strain Asibi virus in mouse and chicken tissue. Since its derivation, the mechanism of attenuation of 17D virus has been investigated using three 17D substrains and WT Asibi virus. Although all three substrains of 17D have been sequenced, only one isolate of Asibi has been examined genetically and all interpretation of attenuation is based on this one isolate. Here, we sequenced the genome of Asibi virus from three different laboratories and show that the WT strain is genetically homogenous at the amino acids that distinguish Asibi from 17D vaccine virus.

Wild-Type Yellow Fever Virus RNA in Cerebrospinal Fluid of Child

We report a 3-year-old child who was hospitalized because of severe manifestations of the central nervous system. The child died after 6 days of hospitalization. Analysis of postmortem cerebrospinal fluid showed the presence of yellow fever virus RNA. Nucleotide sequencing confirmed that the virus was wild-type yellow fever virus.

Yellow Fever Virus Genotyping Tool and Investigation of Suspected Adverse Events Following Yellow Fever Vaccination

The yellow fever (YF) vaccine consists of an attenuated virus, and despite its relative safety, some adverse events following YF vaccination have been described. At the end of 2016, Brazil experienced the most massive sylvatic yellow fever outbreak over the last 70 years and an intense campaign of YF vaccination occurred in Minas Gerais state in Southeast Brazil from 2016 to 2018. The present study aimed to develop a genotyping tool and investigate 21 cases of suspected adverse events following YF vaccination. Initial in silico analyses were performed using partial NS5 nucleotide sequences to verify the discriminatory potential between wild-type and vaccine viruses. Samples from patients were screened for the presence of the YFV RNA, using 5′UTR as the target, and then used for amplification of partial NS5 gene amplification, sequencing, and phylogenetic analysis. Genotyping indicated that 17 suspected cases were infected by the wild-type yellow fever virus, but four cases remained inconclusive. The genotyping tool was efficient in distinguishing the vaccine from wild-type virus, and it has the potential to be used for the differentiation of all yellow fever virus genotypes.