Cost-effectiveness of Human Papillomavirus Self-collection Intervention on Cervical Cancer Screening Uptake among Underscreened U.S. Persons with a Cervix

BACKGROUND

We evaluate the cost-effectiveness of human papillomavirus (HPV) self-collection (followed by scheduling assistance for those who were HPV+ or inconclusive) compared with scheduling assistance only and usual care among underscreened persons with a cervix (PWAC).

METHODS

A decision tree analysis was used to estimate the incremental cost-effectiveness ratios (ICER), or the cost per additional PWAC screened, from the Medicaid/state and clinic perspectives. A hypothetical cohort represented 90,807 low-income, underscreened individuals. Costs and health outcomes were derived from the MyBodyMyTest-3 randomized trial except the usual care health outcomes were derived from literature. We performed probabilistic sensitivity analyses (PSA) to evaluate model uncertainty.

RESULTS

Screening uptake was highest in the self-collection alternative (n = 65,721), followed by the scheduling assistance alternative (n = 34,003) and usual care (n = 18,161). The self-collection alternative costs less and was more effective than the scheduling assistance alternative from the Medicaid/state perspective. Comparing the self-collection alternative with usual care, the ICERs were $284 per additional PWAC screened from the Medicaid/state perspective and $298 per additional PWAC screened from the clinic perspective. PSAs demonstrated that the self-collection alternative was cost-effective compared with usual care at a willingness-to-pay threshold of $300 per additional PWAC screened in 66% of simulations from the Medicaid/state perspective and 58% of simulations from the clinic perspective.

CONCLUSIONS

Compared with usual care and scheduling assistance, mailing HPV self-collection kits to underscreened individuals appears to be cost-effective in increasing screening uptake.

IMPACT

This is the first analysis to demonstrate the cost-effectiveness of mailed self-collection in the United States.

Reducing Bias in Estimates of Per Protocol Treatment Effects: A Secondary Analysis of a Randomized Clinical Trial

This secondary analysis of a randomized clinical trial evaluates ways of reducing bias in estimates of per protocol treatment effects.

Assessing intervention effects in a randomized trial within a social network

Studies of social networks provide unique opportunities to assess the causal effects of interventions that may impact more of the population than just those intervened on directly. Such effects are sometimes called peer or spillover effects, and may exist in the presence of interference, that is, when one individual's treatment affects another individual's outcome. Randomization-based inference (RI) methods provide a theoretical basis for causal inference in randomized studies, even in the presence of interference. In this article, we consider RI of the intervention effect in the eX-FLU trial, a randomized study designed to assess the effect of a social distancing intervention on influenza-like-illness transmission in a connected network of college students. The approach considered enables inference about the effect of the social distancing intervention on the per-contact probability of influenza-like-illness transmission in the observed network. The methods allow for interference between connected individuals and for heterogeneous treatment effects. The proposed methods are evaluated empirically via simulation studies, and then applied to data from the eX-FLU trial.

Effect of HPV self-collection kits on cervical cancer screening uptake among under-screened women from low-income US backgrounds (MBMT-3): a phase 3, open-label, randomised controlled trial

BACKGROUND

Most cervical cancer in the USA occurs in under-screened women. The My Body, My Test-3 (MBMT-3) trial sought to assess the efficacy of mailed human papillomavirus (HPV) self-collection kits with appointment-scheduling assistance to increase uptake of cervical cancer screening among under-screened women from low-income backgrounds compared with scheduling assistance alone.

METHODS

MBMT-3 is a phase 3, open-label, two-arm, randomised controlled trial. Participants were recruited from 22 counties in North Carolina state, USA, and we partnered with 21 clinics across these counties. Participants were eligible for inclusion if they were aged 25-64 years, had an intact cervix, were uninsured or enrolled in Medicaid or Medicare, had an income of 250% or less of the US Federal Poverty Level, were living within the catchment area of a trial-associated clinic, and were overdue for screening (ie, Papanicolaou test ≥4 years ago or high-risk HPV test ≥6 years ago). Participants were randomly assigned (2:1) to receive a mailed HPV self-collection kit and assistance for scheduling a free screening appointment (intervention group) or to receive scheduling assistance alone (control group). Randomisation was conducted by county using permuted blocks of nine patients and assignment to group was not masked. Participants in the intervention group were mailed HPV self-collection kits to collect a cervical-vaginal sample and return it by mail for testing. Samples were tested with the Aptima HPV assay (Hologic, San Diego, CA, USA), and participants were informed of high-risk HPV results by telephone call. Trial staff made up to three telephone call attempts to provide scheduling assistance for in-clinic screening for all participants. The primary outcome was cervical cancer screening uptake (ie, attending an in-clinic screening appointment or testing negative for high-risk HPV with a returned self-collected sample) within 6 months of enrolment in the intention-to-treat population. This trial is registered with ClinicalTrials.gov, NCT02651883, and has been completed.

FINDINGS

Recruitment occurred between April 11, 2016, and Dec 16, 2019. 4256 women contacted the trial to participate, of whom 899 (21%) were eligible for inclusion and 697 (78%) returned consent forms. Of those who consented, 461 (66%) women were randomly assigned to the intervention group and 236 (34%) women were randomly assigned to the control group. We excluded 32 ineligible women post-randomisation, leaving 665 for primary analysis. Screening uptake was higher in the intervention group (317 [72%] of 438) than control group (85 [37%] of 227; risk ratio 1·93, 95% CI 1·62-2·31). Among intervention participants, 341 (78%) of 438 returned a self-collection kit. Three participants reported hurt or injury when using the self-collection kit; no participants withdrew due to adverse effects.

INTERPRETATION

Among under-screened women from low-income backgrounds, mailed HPV self-collection kits with scheduling assistance led to greater uptake of cervical cancer screening than scheduling assistance alone. At-home HPV self-collection testing has the potential to increase screening uptake among under-screened women.

FUNDING

National Cancer Institute.

Nonparametric estimation of marked survival data in the presence of dependent censoring

We consider nonparametrically estimating the joint distribution of a survival time and mark variable, where the survival time is subject to right censoring and the mark variable is only observed when the survival time is not censored. The possibility of dependent censoring is allowed for using inverse probability of censoring weights. The proposed estimator is shown to be consistent and asymptotically normal. Finite sample behavior of the proposed methods are investigated via simulation study. Finally, we illustrate the nonparametric estimator from a recent HIV vaccine efficacy trial.

Adolescents Living With or at Risk for HIV: A Pooled Descriptive Analysis of Studies From the Adolescent Medicine Trials Network for HIV/AIDS Interventions

PURPOSE

This study aims to describe the cohort of Adolescent Medicine Trials Network for HIV/AIDS Interventions (ATN) research program participants and evaluate whether the ATN's recently completed 5-year cycle recruited study participants who parallel the populations most impacted by HIV in the United States.

METHODS

Harmonized measures across ATN studies collected at baseline were aggregated for participants aged 13-24 years. Pooled means and proportions stratified by HIV status (at risk for or living with HIV) were calculated using unweighted averages of study-specific aggregate data. Medians were estimated using a weighted median of medians method. Public use 2019 Centers for Disease Control and Prevention surveillance data for state-level new HIV diagnoses and HIV prevalence among US youth aged 13-24 years were obtained for use as reference populations for ATN at-risk youth and youth living with HIV (YLWH), respectively.

RESULTS

Data from 3,185 youth at-risk for HIV and 542 YLWH were pooled from 21 ATN study phases conducted across the United States. Among ATN studies tailored to at-risk youth, a higher proportion of participants were White and a lower proportion were Black/African American and Hispanic/Latinx compared to youth newly diagnosed with HIV in the United States in 2019. Participants in ATN studies tailored to YLWH were demographically similar to YLWH in the United States.

DISCUSSION

The development of data harmonization guidelines for ATN research activities facilitated this cross-network pooled analysis. These findings suggest the ATN's YLWH are representative, but that future studies of at-risk youth should prioritize recruitment strategies to enroll more participants from African American and Hispanic/Latinx populations.

Infant rhesus macaques immunized against SARS-CoV-2 are protected against heterologous virus challenge 1 year later

The U.S. Food and Drug Administration only gave emergency use authorization of the BNT162b2 and mRNA-1273 SARS-CoV-2 vaccines for infants 6 months and older in June 2022. Yet questions regarding the durability of vaccine efficacy, especially against emerging variants, in this age group remain. We demonstrated previously that a two-dose regimen of stabilized prefusion Washington SARS-CoV-2 S-2P spike (S) protein encoded by mRNA encapsulated in lipid nanoparticles (mRNA-LNP) or purified S-2P mixed with 3M-052, a synthetic Toll-like receptor (TLR) 7/8 agonist, in a squalene emulsion (Protein+3M-052-SE) was safe and immunogenic in infant rhesus macaques. Here, we demonstrate that broadly neutralizing and spike-binding antibodies against variants of concern (VOCs), as well as T cell responses, persisted for 12 months. At 1 year, corresponding to human toddler age, we challenged vaccinated rhesus macaques and age-matched nonvaccinated controls intranasally and intratracheally with a high dose of heterologous SARS-CoV-2 B.1.617.2 (Delta). Seven of eight control rhesus macaques exhibited severe interstitial pneumonia and high virus replication in the upper and lower respiratory tract. In contrast, vaccinated rhesus macaques had faster viral clearance with mild to no pneumonia. Neutralizing and binding antibody responses to the B.1.617.2 variant at the day of challenge correlated with lung pathology and reduced virus replication. Overall, the Protein+3M-052-SE vaccine provided superior protection to the mRNA-LNP vaccine, emphasizing opportunities for optimization of current vaccine platforms. The observed efficacy of both vaccines 1 year after vaccination supports the implementation of an early-life SARS-CoV-2 vaccine.

Adult HIV-1 incidence across 15 high-burden countries in sub-Saharan Africa from 2015 to 2019: a pooled analysis of nationally representative data

BACKGROUND

Harmonised population-based surveys with recent HIV-1 infection testing algorithms permit pooled cross-sectional estimation of HIV incidence across multiple countries. We aimed to estimate adult HIV-1 incidence rates and number of new infections by sex, age, and subregion in sub-Saharan Africa.

METHODS

We analysed data from 13 Population-Based HIV Impact Assessment (PHIA) surveys and two additional population-based surveys done between 2015 and 2019 in 15 sub-Saharan African countries. HIV-seropositive samples from adults aged 15-59 years were tested for recent HIV-1 infection by use of an algorithm consisting of the HIV-1 limiting antigen avidity enzyme immunoassay, HIV-1 viral load, and qualitative detection of antiretroviral agents. Data were pooled across countries; sampling weights were incorporated to represent all adults in the 15 national populations. Analyses accounted for the complex sample designs. HIV incidence rates, incidence rate differences, and number of new annual infections were estimated.

FINDINGS

Among 445 979 adults sampled, 382 had recent HIV-1 infection. The estimated HIV-1 incidence rate was 3·3 per 1000 person-years (95% CI 2·6-4·0) among women and 2·0 per 1000 person-years (1·2-2·7) among men (incidence rate difference 1·3 per 1000 person-years, 95% CI 0·3-2·3). Among adults aged 15-24 years, the incidence rate was higher for women (3·5 per 1000 person-years) than men (1·2 per 1000 person-years; difference 2·3, 95% CI 0·8-3·8), but infection rates were similar between sexes in all other age groups. The HIV-1 incidence rate was 7·4 per 1000 person-years (95% CI 5·0-9·7) in southern sub-Saharan Africa, 2·3 per 1000 person-years (1·7-2·9) in the eastern subregion, and 0·9 per 1000 person-years (0·6-1·2) in the western and central subregion. 689 000 (95% CI 546 000-833 000) new HIV cases were estimated annually among the 265 million susceptible adults (61·6% in women).

INTERPRETATION

HIV-1 incidence and number of new infections differed by age, sex, and subregion. Approaches for risk stratification are needed to guide comprehensive HIV-1 prevention.

FUNDING

National Institutes of Health.

Illustration of 2 Fusion Designs and Estimators

"Fusion" study designs combine data from different sources to answer questions that could not be answered (as well) by subsets of the data. Studies that augment main study data with validation data, as in measurement-error correction studies or generalizability studies, are examples of fusion designs. Fusion estimators, here solutions to stacked estimating functions, produce consistent answers to identified research questions using data from fusion designs. In this paper, we describe a pair of examples of fusion designs and estimators, one where we generalize a proportion to a target population and one where we correct measurement error in a proportion. For each case, we present an example motivated by human immunodeficiency virus research and summarize results from simulation studies. Simulations demonstrate that the fusion estimators provide approximately unbiased results with appropriate 95% confidence interval coverage. Fusion estimators can be used to appropriately combine data in answering important questions that benefit from multiple sources of information.

Aminobisphosphonates reactivate the latent reservoir in people living with HIV-1

Antiretroviral therapy (ART) is not curative due to the existence of cellular reservoirs of latent HIV-1 that persist during therapy. Current research efforts to cure HIV-1 infection include "shock and kill" strategies to disrupt latency using small molecules or latency-reversing agents (LRAs) to induce expression of HIV-1 enabling cytotoxic immune cells to eliminate infected cells. The modest success of current LRAs urges the field to identify novel drugs with increased clinical efficacy. Aminobisphosphonates (N-BPs) that include pamidronate, zoledronate, or alendronate, are the first-line treatment of bone-related diseases including osteoporosis and bone malignancies. Here, we show the use of N-BPs as a novel class of LRA: we found in ex vivo assays using primary cells from ART-suppressed people living with HIV-1 that N-BPs induce HIV-1 from latency to levels that are comparable to the T cell activator phytohemagglutinin (PHA). RNA sequencing and mechanistic data suggested that reactivation may occur through activation of the activator protein 1 signaling pathway. Stored samples from a prior clinical trial aimed at analyzing the effect of alendronate on bone mineral density, provided further evidence of alendronate-mediated latency reversal and activation of immune effector cells. Decay of the reservoir measured by IPDA was however not detected. Our results demonstrate the novel use of N-BPs to reverse HIV-1 latency while inducing immune effector functions. This preliminary evidence merits further investigation in a controlled clinical setting possibly in combination with therapeutic vaccination.

Patterns of use of recombinant zoster vaccine among commercially-insured immunocompetent and immunocompromised adults 50-64 years old in the United States

PURPOSE

The Centers for Disease Control and Prevention (CDC) recommends recombinant zoster vaccination (RZV) for adults ≥ 50 years to prevent herpes zoster (HZ) and its sequelae. Initially, no distinct recommendation was made for immunocompromised adults, who experience higher HZ rates and more severe outcomes. We characterized receipt of first RZV dose (initiation) and both doses (completion) over time, and the impact of immune function on RZV uptake among adults aged 50-64 years in the United States.

METHODS

We identified RZV claims from the IBM MarketScan database between 1/1/2018 and 12/31/2019. We characterized immunocompromised enrollees as having malignancy, HIV, solid organ transplant, primary immunosuppression, or medication-induced immunosuppression using inpatient, outpatient, and prescription claims in the 6 months prior to study start. We evaluated patterns of vaccine uptake by demographic and healthcare access characteristics and immune status.

RESULTS

The cumulative incidence of RZV initiation during the study period was 10.0%. Incidence increased with age and number of medical office visits, and was higher among women, urban residents, high-deductible insurance beneficiaries, and those who were immunocompromised compared to immunocompetent. Among immunocompromised adults, RZV initiation was highest among those with HIV and primary immunodeficiencies. Of those who initiated RZV, 89.5% received both doses. RZV completion was highest among those who received the first dose at a pharmacy. Most enrollees (88.6%) who completed RZV vaccination did so within the recommended dosing schedule.

CONCLUSIONS

RZV uptake was low in the two years since the CDC recommendation, and differed by demographic, healthcare access, and clinical characteristics. Initiation rates were higher among immunocompromised adults compared to immunocompetent adults, despite no CDC recommendation for vaccination in these groups during the study period. The CDC has since recommended RZV for immunocompromised individuals, and our findings may inform efforts to increase RZV uptake in individuals at higher risk of severe disease.

Corrigendum: Reliable estimation of CD8 T cell inhibition of in vitro HIV-1 replication

[This corrects the article DOI: 10.3389/fimmu.2021.666991.].

Propensity Score in the Face of Interference: Discussion of

Rosenbaum and Rubin's (1983) propensity score revolutionized the field of causal inference and has emerged as a standard tool when researchers reason about cause-and-effect relationship across many disciplines. This discussion centers around the key "no interference" assumption in Rosenbaum and Rubin's original development of the propensity score and reviews some recent advances in extending the propensity score to studies involving dependent happenings.

Unique Molecular Identifiers and Multiplexing Amplicons Maximize the Utility of Deep Sequencing To Critically Assess Population Diversity in RNA Viruses

Next generation sequencing (NGS)/deep sequencing has become an important tool in the study of viruses. The use of unique molecular identifiers (UMI) can overcome the limitations of PCR errors and PCR-mediated recombination and reveal the true sampling depth of a viral population being sequenced in an NGS experiment. This approach of enhanced sequence data represents an ideal tool to study both high and low abundance drug resistance mutations and more generally to explore the genetic structure of viral populations. Central to the use of the UMI/Primer ID approach is the creation of a template consensus sequence (TCS) for each genome sequenced. Here we describe a series of experiments to validate several aspects of the Multiplexed Primer ID (MPID) sequencing approach using the MiSeq platform. We have evaluated how multiplexing of cDNA synthesis and amplicons affects the sampling depth of the viral population for each individual cDNA and amplicon to understand the relationship between broader genome coverage versus maximal sequencing depth. We have validated reproducibility of the MPID assay in the detection of minority mutations in viral genomes. We have also examined the determinants that allow sequencing reads of PCR recombinants to contaminate the final TCS data set and show how such contamination can be limited. Finally, we provide several examples where we have applied MPID to analyze features of minority variants and describe limits on their detection in viral populations of HIV-1 and SARS-CoV-2 to demonstrate the generalizable utility of this approach with any RNA virus.

Estimating the Number of Persons with HIV in Jails via Web Scraping and Record Linkage

This paper presents methods to estimate the number of persons with HIV in North Carolina jails by applying finite population inferential approaches to data collected using web scraping and record linkage techniques. Administrative data are linked with web-scraped rosters of incarcerated persons in a nonrandom subset of counties. Outcome regression and calibration weighting are adapted for state-level estimation. Methods are compared in simulations and are applied to data from the US state of North Carolina. Outcome regression yielded more precise inference and allowed for county-level estimates, an important study objective, while calibration weighting exhibited double robustness under misspecification of the outcome or weight model.

Paired serial limiting dilution assays

Serial limiting dilution (SLD) assays are a widely used tool in many areas of public health research to measure the concentration of target entities. This concentration can be estimated via maximum likelihood. Asymptotic as well as exact inference methods have been proposed for hypothesis testing and confidence interval construction in this one-sample problem. However, in many scientific applications, it may be of interest to compare the concentration of target entities between a pair of samples and construct valid confidence intervals for the difference in concentrations. In this paper, an exact, computationally efficient inferential procedure is proposed for hypothesis testing and confidence interval construction in the two-sample SLD assay problem. The proposed exact method is compared to an approach based on asymptotic approximations in simulation studies. The methods are illustrated using data from the University of North Carolina HIV Cure Center.

Targeted maximum likelihood estimation of causal effects with interference: A simulation study

Interference, the dependency of an individual's potential outcome on the exposure of other individuals, is a common occurrence in medicine and public health. Recently, targeted maximum likelihood estimation (TMLE) has been extended to settings of interference, including in the context of estimation of the mean of an outcome under a specified distribution of exposure, referred to as a policy. This paper summarizes how TMLE for independent data is extended to general interference (network-TMLE). An extensive simulation study is presented of network-TMLE, consisting of four data generating mechanisms (unit-treatment effect only, spillover effects only, unit-treatment and spillover effects, infection transmission) in networks of varying structures. Simulations show that network-TMLE performs well across scenarios with interference, but issues manifest when policies are not well-supported by the observed data, potentially leading to poor confidence interval coverage. Guidance for practical application, freely available software, and areas of future work are provided.

Racial and ethnic differences in cervical cancer screening barriers and intentions: The My Body My Test-3 HPV self-collection trial among under-screened, low-income women

Under-screened women are more likely to be diagnosed with invasive cervical cancer at later stages and have worse survival outcomes. Under- or un-insured women, low-income women, and minoritized groups face barriers to screening. Intention to screen is an indicator of future screening behavior, yet is understudied among low-income, under-screened women. Participants were 710 low-income, uninsured or publicly insured women ages 25-64 years in North Carolina who were not up to date on cervical cancer screening according to national guidelines. Participants were asked about barriers to screening and intention to screen. We estimated reported barriers to cervical cancer screening stratified by race and ethnicity (categorized as White, Black, and Hispanic) and assessed predictors of intention to screen. Sixty-one percent of all participants reported 5 or more barriers to screening. The most commonly reported reasons for not getting screened were lack of insurance (White: 71%, Black: 62%, Hispanic/Latina: 63%) and cost (White: 55%, Black: 44%, Hispanic/Latina: 61%). Women were more likely to have an intention to screen if they reported "it was not hard to get screening" (OR: 1.47 (1.00, 2.15)). Older women reported being less likely to intend to screen. Black women reported being more likely to intend to screen than White women. Lack of health insurance and cost were frequently reported barriers to cervical cancer screening. Increasing knowledge of affordable clinics and expanding access to Medicaid may reduce barriers and increase cervical cancer screening uptake.

Reservoir-Style Polymeric Drug Delivery Systems: Empirical and Predictive Models for Implant Design

Controlled drug delivery systems can provide sustained release profiles, favorable pharmacokinetics, and improved patient adherence. Here, a reservoir-style implant comprising a biodegradable polymer, poly(ε-caprolactone) (PCL), was developed to deliver drugs subcutaneously. This work addresses a key challenge when designing these implantable drug delivery systems, namely the accurate prediction of drug release profiles when using different formulations or form factors of the implant. The ability to model and predict the release behavior of drugs from an implant based on their physicochemical properties enables rational design and optimization without extensive and laborious in vitro testing. By leveraging experimental observations, we propose a mathematical model that predicts the empirical parameters describing the drug diffusion and partitioning processes based on the physicochemical properties of the drug. We demonstrate that the model enables an adequate fit predicting empirical parameters close to experimental values for various drugs. The model was further used to predict the release performance of new drug formulations from the implant, which aligned with experimental results for implants exhibiting zero-order release kinetics. Thus, the proposed empirical models provide useful tools to inform the implant design to achieve a target release profile.

Extended Human Papillomavirus Genotyping to Predict Progression to High-Grade Cervical Precancer: A Prospective Cohort Study in the Southeastern United States

BACKGROUND

High-risk human papillomavirus (hrHPV) testing is utilized in primary cervical cancer screening, generally along with cytology, to triage abnormalities to colposcopy. Most screening-based hrHPV testing involves pooled detection of any hrHPV or of HPV16/18. Cervical neoplasia progression risks based on extended hrHPV genotyping-particularly non-16/18 hrHPV types-are not well characterized. HPV genotype-specific incidence of high-grade cervical intraepithelial neoplasia or more severe (CIN2+) following an abnormal screening result was examined.

METHODS

We assessed a US-based prospective, multiracial, clinical cohort of 343 colposcopy patients with normal histology (n = 226) or CIN1 (n = 117). Baseline cervical samples underwent HPV DNA genotyping, and participants were followed up to 5 years. Genotype-specific CIN2+ incidence rates (IR) were estimated with accelerated failure time models. Five-year CIN2+ risks were estimated nonparametrically for hierarchical hrHPV risk groups (HPV16; else HPV18/45; else HPV31/33/35/52/58; else HPV39/51/56/59/68).

RESULTS

At enrollment, median participant age was 30.1 years; most (63%) were hrHPV-positive. Over follow-up, 24 participants progressed to CIN2+ (7.0%). CIN2+ IR among hrHPV-positive participants was 3.4/1,000 person-months. CIN2+ IRs were highest for HPV16 (8.3), HPV33 (7.8), and HPV58 (4.9). Five-year CIN2+ risk was higher for HPV16 (0.34) compared with HPV18/45 (0.12), HPV31/33/35/52/58 (0.12), and HPV39/51/56/59/68 (0.16) (P = 0.05).

CONCLUSIONS

Non-16/18 hrHPV types are associated with differential CIN2+ progression rates. HPV16, 33, and 58 exhibited the highest rates over 5 years. HPV risk groups warrant further investigation in diverse US populations.

IMPACT

These novel data assessing extended HPV genotyping in a diverse clinical cohort can inform future directions to improve screening practices in the general population.

Leveraging antigenic seniority for maternal vaccination to prevent mother-to-child transmission of HIV-1

The development of a maternal HIV vaccine to synergize with current antiretroviral drug prophylaxis can overcome implementation challenges and further reduce mother-to-child transmission (MTCT) of HIV. Both the epitope-specificity and autologous neutralization capacity of maternal HIV envelope (Env)-specific antibodies have been implicated in decreased risk of MTCT of HIV. Our goal was to determine if heterologous HIV Env immunization of SHIV.C.CH505-infected, ART-suppressed female rhesus macaques (RMs) could boost autologous Env-specific antibodies. SHIV.C.CH505-infected female RMs (n = 12), began a daily ART regimen at 12 weeks post-infection (wpi), which was continued for 12 weeks. Starting 2 weeks after ART initiation, RMs received 3 monthly immunizations with HIV b.63521/1086.C gp120 or placebo (n = 6/group) vaccine with adjuvant STR8S-C. Compared to the placebo-immunized animals, Env-vaccinated, SHIV-infected RMs exhibited enhanced IgG binding, avidity, and ADCC responses against the vaccine immunogens and the autologous SHIV.C.CH505 Env. Notably, the Env-specific memory B cells elicited by heterologous vaccination were dominated by cells that recognized the SHIV.C.CH505 Env, the antigen of primary exposure. Thus, vaccination of SHIV-infected, ART-suppressed RMs with heterologous HIV Envs can augment multiple components of the antibody response against the Env antigen of primary exposure, suggesting antigenic seniority. Our results suggest that a universal maternal HIV vaccination regimen can be developed to leverage antigenic seniority in targeting the maternal autologous virus pool.

Abstract 2230: Extended human papillomavirus genotyping to predict progression to high-grade cervical precancer: A prospective cohort study in the southeastern United States

Background: High-risk human papillomavirus (hrHPV) testing is recommended for primary cervical cancer screening and is used alongside cytology to triage screening abnormalities to colposcopy. Most screening-based hrHPV tests involve pooled detection of any hrHPV type or of HPV 16/18 only. Extended HPV genotyping, particularly of non-16/18 hrHPV types, may improve risk stratification for millions of cervical abnormalities detected each year, but HPV genotype-specific progression risks are not well characterized. HPV genotype-specific incidence of high-grade cervical intraepithelial neoplasia or more severe (CIN2+) was examined among individuals with normal or low-grade (CIN1) histology following an abnormal screening cytology result.

Methods: A US-based prospective, multiracial cohort of 343 colposcopy referral patients with normal (n=226) or CIN1 (n=117) histology was assessed. Baseline cervical samples underwent HPV DNA genotyping. Participants were followed for up to five years. Genotype-specific CIN2+ incidence rates (IR) were estimated with accelerated failure time models for interval-censored data. Cumulative CIN2+ risk over five years was estimated non-parametrically and compared for HPV risk groups (HPV 16/31/18, else HPV 33/58/52/45, else HPV 39/68/35/51/59/56/66) and age groups (ages 21-24, 25-29, 30+).

Results: At enrollment, median participant age was 30.1 years; 67.1% were hrHPV-positive. During follow-up (median 24.3 months), 24 participants progressed to CIN2+ (7.0%; 6.2% among normal histology and 8.6% among CIN1). CIN2+ IR among hrHPV-positive participants was 3.2/1,000 person-months. CIN2+ IRs were highest for HPV 16 (IR 8.3; 95% CI 4.1, 16.6), HPV 33 (IR 7.8; 95% CI 2.0, 31.3), and HPV 58 (IR 4.9; 95% CI 1.2, 19.6). IRs were highest for HPV 16, 68, and 33 among normal histology and for HPV 33, 31, 16, and 58 among CIN1. Five-year CIN2+ risks were 0.27 for HPV 16/31/18, 0.11 for HPV 33/58/52/45, and 0.13 for HPV 39/68/35/51/59/56/66 (p=0.04). CIN2+ risk did not differ by age group.

Conclusion: In addition to the established HPV type 16, HPV 33 and 58 were consistently predictive of progression to CIN2+ over a five-year period in this cohort. These findings also support the utility of HPV risk groups to stratify women with non-16/18 hrHPV positivity who exhibit differential risks of progression. Additionally, HPV risk groups appear to predict progression regardless of age; thus, although hrHPV testing is not recommended for initial screening of women under 30 years of age, it may be a risk-stratification tool for these younger women, once a cervical abnormality is found. In conclusion, extended genotyping of non-16/18 hrHPV may be useful to identify individuals with normal or low-grade histology results who are at increased risk of progression to CIN2+, thereby improving the efficacy of cervical cancer screening.

Citation Format: Alexandra Bukowski, Cathrine Hoyo, Michael G. Hudgens, Wendy R. Brewster, Fidel Valea, Rex C. Bentley, Adriana C. Vidal, Rachel L. Maguire, John W. Schmitt, Susan K. Murphy, Kari E. North, Jennifer S. Smith. Extended human papillomavirus genotyping to predict progression to high-grade cervical precancer: A prospective cohort study in the southeastern United States [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 2230.

CD4 T cell memory restoration upon antiretroviral initiation in people living with HIV

HIV infection depletes CD4 T cells and dysregulates formation of long-lived memory CD4 T cells. Studies show that antiretroviral therapy (ART) in people with HIV (PWH) more effectively restores CD4 T cell memory phenotypes when initiated early (< Fiebig V). We used a 31 marker mass cytometry panel to assess CD4 T cell phenotype in PWH treated in acute infection (AHI) (median 2.3 years post ART initiation) and chronic infection (CHI) (median 5.8 years post ART initiation) compared to healthy donors (HD) (n=10 per group). Markers of activation (HLA-DR, CD25), exhaustion (PD-1), survival (Bcl-2) and memory (CD127) were examined. CD4 T cell memory phenotypes of AHI clustered closely with HD whereas CHI had fewer central memory CD4 T cells. We also examined IL-7 signaling in CD4 T cells, measuring STAT5 phosphorylation (pSTAT5) in response to IL-7. CHI exhibited significantly lower pSTAT5 than HD in contrast to AHI who exhibited restored IL-7 signaling. This suggests ongoing and underappreciated functional defects in CD4 T cells in CHI. To examine this further, we are completing detailed analysis of CHI before and after ART initiation (pre-ART, day 2, 7, 10, 14, 28, month 5, 9 and 18). Data will be compared to our recent work showing that CD4 T cell memory subsets, activation and exhaustion markers are highly stable in durably suppressed CHI on ART over 19–27 months. New work is examining CD4 T cell function in immunological non-responders (INR) who fail to restore CD4 counts following ART. Altogether these studies will inform how HIV impacts formation of both CD4 memory and the HIV reservoir (which is largely harbored in long lived memory CD4 T cells) following ART initiation, potentially identifying novel therapeutic targets to accelerate HIV cure in CHI.

This work was made possible by the National Institute of Allergy and Infectious Diseases U01 AI131310, Collaboratory of AIDS Researchers for Eradication (UM1 AI164567) and UNC WIHS (U01 AI103390).

Conserved-region MVA vaccines can shift HIV T cell immunodominance in PWH on ART - the M&M Study

CD8+ T cell immunity is essential to the control of HIV viremia. We examined the safety and immunogenicity of MVA-vectored vaccines expressing highly conserved HIV regions in a first-in-man Phase I study in people living with HIV on ART. Participants received a single intramuscular dose of MVA.tHIVconsv3 (M3), MVA.tHIVconsv4 (M4), combined M3+M4 or saline in a 7:7:7:3 ratio. M3 and M4 span the same 6 HIV regions but differ by approximately 10% of amino acids; a design to increase vaccine coverage of circulating HIV variants. We employed ex vivo IFN-g ELISpot assays to measure changes in HIV-specific T cell magnitude and breadth to M3 and/or M4 immunogens following vaccination. We also examined whether M3, M4 or M3+M4 vaccination increased the ability of CD8+ T cells inhibit HIV in vitro replication.

The M&M study is fully enrolled but presently is blinded. Analysis of blinded data show that vaccination was safe and well tolerated. Vaccination induced strong increases in the T cell response to M3, M4 vaccine immunogens producing a 2- to 18-fold increase in magnitude in 16/20 participants tested to date. M3/M4-specific T cell breadth also increased across participants. Vaccine-associated T cell responses mostly remained elevated (>2-fold increase) for at least 70 days post-vaccination visit. Vaccination was also associated with clear and sustained increases in in vitro virus inhibition. The percentage of the total HIV T cell response targeting conserved HIV regions in participants increased on average from 40 to 60% post-vaccination, suggesting M3/M4/M3+4 vaccination successfully produced a sustained shift in T cell immunodominance. Unblinded data will be presented at this meeting.

Supported by U01AI131310

CD8 T Cell Virus Inhibition Assay Protocol

The human immunodeficiency virus (HIV)-1 viral inhibition assay (VIA) measures CD8⁺ T cell-mediated inhibition of HIV replication in CD4⁺ T cells and is increasingly used for clinical testing of HIV vaccines and immunotherapies. Different VIAs that differ in length of CD8:CD4 T cell culture periods (6-13 days), purity of CD4 cultures [isolated CD4⁺ T cells or CD8⁺ depleted peripheral blood mononuclear cells (PBMCs)], HIV strains (laboratory strains, isolates, reporter viruses) and read-outs of virus inhibition (p24 ELISA, intracellular measurement of p24, luciferase reporter expression, and viral gag RNA) have been reported. Here, we describe multiple modifications to a 7-day VIA protocol, the most impactful being the introduction of independent replicate cultures for both HIV infected-CD4 (HIV-CD4) and HIV-CD4:CD8 T cell cultures. Virus inhibition was quantified using a ratio of weighted averages of p24⁺ cells in replicate cultures and the corresponding 95% confidence intervals. We identify methodological and analysis changes that could be incorporated into other protocols to improve assay reproducibility. We found that in people living with HIV (PLWH) on antiretroviral therapy (ART), CD8 T cell virus inhibition was largely stable over time, supporting the use of this assay and/or analysis methods to examine therapeutic interventions. Graphic abstract.