Convalescent plasma donors show enhanced cross-reactive neutralizing antibody response to antigenic variants of SARS-CoV-2 following immunization.

BACKGROUND: The therapeutic benefit of convalescent plasma (CP) therapy to treat COVID-19 may derive from neutralizing antibodies (nAbs) to SARS-CoV-2. To investigate the effects of antigenic variation on neutralization potency of CP, we compared nAb titers against prototype and recently emerging strains of SARS-CoV-2, including Delta and Omicron, in CP donors previously infected with SARS-CoV-2 before and after immunization. METHODS AND MATERIALS: Samples were assayed from previously SARS-CoV-2 infected donors before (n = 17) and after one (n = 43) or two (n = 71) doses of Astra-Zeneca or Pfizer vaccinations. Ab titers against Wuhan/wild type (WT), Alpha, Beta, and Delta SARS-CoV-2 strains were determined by live virus microneutralization assay while titers to Omicron used a focus reduction neutralization test. Anti-spike antibody was assayed by Elecsys anti-SARS-CoV-2 quantitative spike assay (Roche). RESULTS: Unvaccinated donors showed a geometric mean titer (GMT) of 148 against WT, 80 against Alpha but mostly failed to neutralize Beta, Delta, and Omicron strains. Contrastingly, high GMTs were observed in vaccinated donors against all SARS-CoV-2 strains after one vaccine dose (WT:703; Alpha:692; Beta:187; Delta:215; Omicron:434). By ROC analysis, reactivity in the Roche quantitative Elecsys spike assay of 20,000 U/mL was highly predictive of donations with nAb titers of ≥1:640 against Delta (90% sensitivity; 97% specificity) and ≥1:320 against Omicron (89% sensitivity; 81% specificity). DISCUSSION: Vaccination of previously infected CP donors induced high levels of broadly neutralizing antibodies against circulating antigenic variants of SARS-CoV-2. High titer donations could be reliably identified by automated quantitative anti-spike antibody assay, enabling large-scale preselection of high-titer convalescent plasma.

Mental disorder, service use, and barriers to care among 500 homeless people in 3 different urban settings.

OBJECTIVE: To determine the standardized rates of mental disorder, health service use and barriers to care in a representatively diverse sample of homeless adults in three different sized urban centers in British Columbia, Canada. METHOD: Five hundred homeless adults from Vancouver, Victoria and Prince George were recruited. The MINI-International Neuropsychiatric Interview PLUS was used to determine current and lifetime rates of mental disorder, mental disorder episodes and suicidality. Health service use and barriers to care were recorded. RESULTS: Overall, 92.8 % of participants met criteria for a current mental disorder: 82.6 % for alcohol or drug dependence, 57.3 % anxiety disorder, 31.5 % mood disorder. Over half (53.4 %) met criteria for a concurrent disorder. Only 14.9 % had seen a psychiatrist and 12.7 % a mental health team in the year prior to the survey. Most common barriers included being poorly connected to the system of care and issues related to homelessness. Mental disorder rates across sites were high, however, differences were found that reflected the composition of the samples. CONCLUSION: Improving the mental health state of the homeless will require significant capacity for mental health and concurrent disorder programming that is tailored to the community it intends to serve. Demographic features of the population may help in directing assessments of need.

The Cedar Project: Negative health outcomes associated with involvement in the child welfare system among young Indigenous people who use injection and non-injection drugs in two Canadian cities.

OBJECTIVES: Indigenous leaders and child and family advocates are deeply concerned about the health impacts of the child welfare system, including HIV vulnerability. The objectives of this study were to describe the prevalence of having been apprehended into the child welfare system and associated HIV vulnerabilities among young Indigenous people who use drugs. METHODS: The Cedar Project is a cohort of young Indigenous people ages 14-30 years who use illicit drugs in Vancouver and Prince George, British Columbia. Multivariable logistic regression modeling determined associations between a history of involvement in the child welfare system and vulnerability to HIV infection. RESULTS: Of 605 participants, 65% had been taken from their biological parents. Median age of first apprehension was 4 years old. Having been sexually abused, having a parent who attended residential school and being HIV-positive were all independently associated with having been involved in the child welfare system. Participants who had been involved in the child welfare system were also more likely to have been homeless, paid for sex, diagnosed and hospitalized with mental illness, self-harmed, thought about suicide, and attempted suicide. Among participants who used injection drugs, those who had been involved in child welfare were more likely to have shared needles and overdosed. CONCLUSION: This study has found compelling evidence that young Indigenous people who use drugs in two cities in BC are experiencing several distressing health outcomes associated with child welfare involvement, including HIV infection. Jurisdictional reforms and trauma-informed programs that use culture as intervention are urgently needed.