Neutralizing activity and 3-month durability of tixagevimab and cilgavimab prophylaxis against Omicron sublineages in transplant recipients

Neutralizing antibody (nAb) responses are attenuated in solid organ transplant recipients (SOTRs) despite severe acute respiratory syndrome-coronavirus-2 vaccination. Preexposure prophylaxis (PrEP) with the antibody combination tixagevimab and cilgavimab (T+C) might augment immunoprotection, yet in vitro activity and durability against Omicron sublineages BA.4/5 in fully vaccinated SOTRs have not been delineated. Vaccinated SOTRs, who received 300 + 300 mg T+C (ie, full dose), within a prospective observational cohort submitted pre and postinjection samples between January 31, 2022, and July 6, 2022. The peak live virus nAb was measured against Omicron sublineages (BA.1, BA.2, BA.2.12.1, and BA.4), and surrogate neutralization (percent inhibition of angiotensin-converting enzyme 2 receptor binding to full length spike, validated vs live virus) was measured out to 3 months against sublineages, including BA.4/5. With live virus testing, the proportion of SOTRs with any nAb increased against BA.2 (47%-100%; P < .01), BA.2.12.1 (27%-80%; P < .01), and BA.4 (27%-93%; P < .01), but not against BA.1 (40%-33%; P = .6). The proportion of SOTRs with surrogate neutralizing inhibition against BA.5, however, fell to 15% by 3 months. Two participants developed mild severe acute respiratory syndrome-coronavirus-2 infection during follow-up. The majority of fully vaccinated SOTRs receiving T+C PrEP achieved BA.4/5 neutralization, yet nAb activity commonly waned by 3 months postinjection. It is critical to assess the optimal dose and interval of T+C PrEP to maximize protection in a changing variant climate.

Estimating the Influence of Incarceration on Subsequent Experience With Violence Among Black Men Who Have Sex With Men in the HPTN061 Study

Black men who have sex with men (BMSM) are disproportionately incarcerated in the United States. Incarceration is a barrier to health equity and may be a risk factor for experiences of interpersonal violence. However, the effect of incarceration on experienced violence among BMSM is understudied. We examined associations between recent incarceration on subsequent experiences of race- or sexuality-based violence, intimate partner violence, or community violence. We analyzed data from the HPTN 061 study. Analysis includes data on 1,169 BMSM recruited from 6 U.S. cities who were present at baseline as well as 6- and 12-month follow-up interview. We tested if self-reported incarceration between baseline and 6 months was associated with self-reported outcomes between 6 and 12 months using logistic regression with inverse probability of treatment weighting and multiple imputation methods. Experienced outcomes included violence due to race or sexuality, intimate partner violence and aggression, and community violence (i.e., gang violence, robbery, shooting). Approximately 14% reported incarceration between baseline and 6 months and 90% reported experiencing violence between 6 and 12 months. In adjusted analyses, incarceration was associated with subsequent race- or sexuality-based violence [aOR (adjusted odds ratio) range: 1.25-1.41, 95% CI (confidence interval) range: 1.00-1.74], experiences of physical abuse and aggression from intimate partners (aOR: 2.35; 95% CI: 1.50, 3.70) and community violence (OR 1.82; 95% CI: 1.23, 2.72). Recent incarceration experience increased risk of exposure to future violence in this population. Mixed methods research examining mediating paths between and downstream effects of incarceration and violence on the wellbeing and health of BMSM is needed. We implore researchers to study violence and incarceration among BMSM. Practitione should implement strategies such as trauma-informed interventions, and policies strengthening the social and economic support needs of Black populations.

Omicron BA.1 and BA.2 Neutralizing Activity Following Pre-Exposure Prophylaxis with Tixagevimab plus Cilgavimab in Vaccinated Solid Organ Transplant Recipients

Neutralizing antibody responses are attenuated in many solid organ transplant recipients (SOTRs) despite SARS-CoV-2 vaccination. Pre-exposure prophylaxis (PrEP) with the monoclonal antibody combination Tixagevimab and Cilgavimab (T+C) might augment immunoprotection, yet activity against Omicron sublineages in vaccinated SOTRs is unknown. Vaccinated SOTRs who received 300+300mg T+C (either single dose or two 150+150mg doses) within a prospective observational cohort submitted pre- and post-injection samples between 1/10/2022-4/4/2022. Binding antibody (anti-receptor binding domain [RBD], Roche) and surrogate neutralization (%ACE2 inhibition; ≥20% connoting neutralizing inhibition, Meso Scale Discovery) were measured against variants including Omicron sublineages BA.1 and BA.2. Data were analyzed using the Wilcoxon matched-pairs signed-rank test and McNemar's test. Among 61 participants, median (IQR) anti-RBD increased from 424 (IQR <0.8-2322.5) to 3394.5 (IQR 1403.9-7002.5) U/ml post T+C (p<0.001). The proportion demonstrating vaccine strain neutralizing inhibition increased from 46% to 100% post-T+C (p<0.001). BA.1 neutralization was low and did not increase (8% to 16% of participants post-T+C, p=0.06). In contrast, BA.2 neutralization increased from 7% to 72% of participants post-T+C (p<0.001). T+C increased anti-RBD levels, yet BA.1 neutralizing activity was minimal. Encouragingly, BA.2 neutralization was augmented and in the current variant climate T+C PrEP may serve as a useful complement to vaccination in high-risk SOTRs.