Post-exposure prophylaxis against SARS-CoV-2 in close contacts of confirmed COVID-19 cases (CORIPREV): study protocol for a cluster-randomized trial

Motivations for enrollment in a COVID-19 ring-based post-exposure prophylaxis trial: qualitative examination of participant experiences

BACKGROUND

Ring-based studies are a novel research design commonly used for research involving infectious diseases: contacts of newly infected individuals form a ring that is targeted for interventions (e.g., vaccine, post-exposure prophylaxis). Given the novelty of the research design, it is critical to obtain feedback from participants on their experiences with ring-based studies to help with the development of future trials.

METHODS

In 2021, we conducted 26 semi-structured interviews with adult participants of a COVID-19 ring-based post-exposure prophylaxis trial based in Canada. We applied a purposive sampling approach and electronically recruited participants who tested positive for COVID-19 (Index Cases) and either agreed or declined for the study team to contact their potentially exposed contacts. We also included individuals who participated in the trial after being potentially exposed to an Index Case (known as Ring Members), and those who declined to participate after potential exposure. The methodological design of semi-structured interviews allowed participants to share their opinions and experiences in the trial (e.g., elements they enjoyed and disliked regarding their participation in the study).

RESULTS

The majority of participants in our study were women (62%) and the average age was 37.3 years (SD = 13.2). Overall, participants reported being highly satisfied with partaking in the ring-based trial. Notably, no substantial complaints were voiced about the trial's design involving contact after exposure. The most common reason of satisfaction was the knowledge of potentially helping others by advancing knowledge for a greater cause (e.g., development of potential treatment to prevent SARS-CoV-2 infection). Other reasons were curiosity about participating in a trial, and an activity to fill free time during the pandemic. A central element of dislike was confusion about instructions with the trial (e.g., independent at home SARS-CoV-2 testing). Additionally, maintaining confidentiality was a crucial concern for participants, who sought assurance that their data would not be shared beyond the scope of the study.

CONCLUSIONS

Our results have the potential to inform future research, including clinical trials such as ring-based studies, by incorporating insights from participants' experiences into the development of study protocols. Despite some protocol-related challenges, participants expressed high satisfaction, driven by the desire to advance science and potentially aid others.

Concordance between SARS-CoV-2 index individuals and their household contacts on index individual COVID-19 transmission cofactors: a comparison of self-reported and contact-reported information

BACKGROUND

Following the outbreak of the COVID-19 pandemic, several clinical trials have evaluated postexposure prophylaxis (PEP) among close contacts of an index individual with a confirmed SARS-CoV-2 infection. Because index individuals do not directly inform the efficacy of prevention interventions, they are seldom enrolled in COVID-19 PEP studies. However, adjusting for prognostic covariates such as an index individual's COVID-19 illness and risk behaviors can increase precision in PEP efficacy estimates, so approaches to accurately collecting this information about the index individual are needed. This analysis aimed to assess whether surveying household contacts captures the same information as surveying the index individual directly.

METHODS

REGN 2069/CoVPN 3502, a randomized controlled trial of COVID-19 PEP, enrolled household contacts of SARS-CoV-2 index individuals. CoVPN 3502-01 retrospectively enrolled and surveyed the index individuals. We compared responses to seven similar questions about the index individuals' transmission cofactors that were asked in both studies. We estimated the percent concordance between index individuals and their household contacts on each question, with 50% concordance considered equivalent to random chance.

RESULTS

Concordance between index individuals and contacts was high on the most objective questions, approximately 97% (95% CI: 90-99%) for index individual age group and 96% (88-98%) for hospitalization. Concordance was moderate for symptoms, approximately 85% (75-91%). Concordance on questions related to the index individual's behavior was only slightly better or no better than random: approximately 62% (51-72%) for whether they received COVID-19 treatment, 68% (57-77%) for sharing a bedroom, 70% (59-79%) for sharing a common room, and 49% (39-60%) for mask wearing at home. However, while contacts were surveyed within 96 h of the index individual testing positive for SARS-CoV-2, the median time to enrollment in CoVPN 3502-01 was 240 days, which may have caused recall bias in our results.

CONCLUSIONS

Our results suggest a need to survey index individuals directly in order to accurately capture their transmission cofactors, rather than relying on their household contacts to report on their behavior. The lag in enrolling participants into CoVPN 3502-01 also highlights the importance of timely enrollment to minimize recall bias.

Mitoquinone mesylate as post-exposure prophylaxis against SARS-CoV-2 infection in humans: an exploratory single center pragmatic open label non-randomized pilot clinical trial with matched controls

BACKGROUND

An ongoing important need exists to rapidly develop novel therapeutics for COVID-19 that will retain antiviral efficacy in the setting of rapidly evolving SARS-CoV-2 variants and potential future development of resistance of SARS-COV-2 to remdesivir and protease inhibitors. To date, there is no FDA-approved treatment for post-exposure prophylaxis against SAR-CoV-2. We have shown that the mitochondrial antioxidant mitoquinone/mitoquinol mesylate (Mito-MES), a dietary supplement, has antiviral activity against SARS-CoV-2 in vitro and in SARS-CoV-2 infected K18-hACE2 mice.

METHODS

In this exploratory, pragmatic open label clinical trial (ClinicalTrials.gov identifier NCT05381454), we studied whether Mito-MES is an effective post-exposure prophylaxis treatment in people who had high-grade unmasked exposures to SARS-CoV-2 within 5 days prior to study entry. Participants were enrolled in real-world setting in Los Angeles, United States between May 1 and December 1, 2022 and were assigned to either mito-MES 20 mg daily for 14 days (n = 40) or no mito-MES (controls) (n = 40). The primary endpoint was development of SARS-CoV-2 infection based on 4 COVID-19 diagnostic tests [rapid antigen tests (RATs) or PCR] performed during the study period (14 days post exposure).

FINDINGS

Out of 40 (23 females; 57.5%) study participants who took Mito-MES, 12 (30%) developed SARS-CoV-2 infection compared to 30 of the 40 controls (75%) (difference -45.0%, 95% confidence intervals (CI): -64.5%, -25.5%). Out of 40 (19 females; 47.5%) study participants in the control group, 30 (75.0%) had at least one positive COVID-19 diagnostic test and 23 (57.5%) were symptomatic. With regards to key secondary outcomes, among symptomatic SARS-CoV-2 infections, the median duration of viral symptoms was lower in the Mito-MES group (median 3.0, 95% CI 2.75, 3.25) compared to the control group (median 5.0, 95% CI 4.0, 7.0). None of the study participants was hospitalized or required oxygen therapy. Mito-MES was well tolerated and no serious side effect was reported in any study participant.

INTERPRETATION

This work describes antiviral activity of mito-MES in humans. Mito-MES was well tolerated in our study population and attenuated transmission of SARS-CoV-2 infection. Given established safety of Mito-MES in humans, our results suggest that randomized control clinical trials of Mito-MES as post-exposure prophylaxis against SARS-CoV-2 infection are warranted.

FUNDING

This work was supported in part by National Institutes of Health grant R01AG059501 (TK), National Institutes of Health grant R01AG059502 04S1 (TK), NIH/National Center for Advancing Translational Sciences (NCATS) UCLA CTSI Grant Number UL1TR001881 and California HIV/AIDS Research Program grant OS17-LA-002 (TK).

Evaluation of phytoconstituents of Tinospora cordifolia against K417N and N501Y mutant spike glycoprotein and main protease of SARS-CoV-2- an in silico study

Coronavirus disease 2019 (COVID-19) caused appalling conditions over the globe, which is currently faced by the entire human population. One of the primary reasons behind the uncontrollable situation is the lack of specific therapeutics. In such conditions, drug repurposing of available drugs (viz. Chloroquine, Lopinavir, etc.) has been proposed, but various clinical and preclinical investigations indicated the toxicity and adverse side effects of these drugs. This study explores the inhibition potency of phytochemicals from Tinospora cordifolia (Giloy) against SARS CoV-2 drugable targets (spike glycoprotein and Mpro proteins) using molecular docking and MD simulation studies. ADMET, virtual screening, MD simulation, postsimulation analysis (RMSD, RMSF, Rg, SASA, PCA, FES) and MM-PBSA calculations were carried out to predict the inhibition efficacy of the phytochemicals against SARS CoV-2 targets. Tinospora compounds showed better binding affinity than the corresponding reference. Their binding affinity ranges from -9.63 to -5.68 kcal/mole with spike protein and -10.27 to -7.25 kcal/mole with main protease. Further 100 ns exhaustive simulation studies and MM-PBSA calculations supported favorable and stable binding of them. This work identifies Nine Tinospora compounds as potential inhibitors. Among those, 7-desacetoxy-6,7-dehydrogedunin was found to inhibit both spike (7NEG) and Mpro (7MGS and 6LU7) proteins, and Columbin was found to inhibit selected spike targets (7NEG and 7NX7). In all the analyses, these compounds performed well and confirms the stable binding. Hence the identified compounds, advocated as potential inhibitors can be taken for further in vitro and in vivo experimental validation to determine their anti-SARS-CoV-2 potential.Communicated by Ramaswamy H. Sarma.

HIV and COVID-19 Disease

Despite effective antiretroviral therapy (ART), HIV infected individuals throughout the world remain at significant risk of respiratory infections and non-communicable disease. Severe disease from SARS-CoV-2 is associated with a hyperinflammatory phenotype which manifests in the lungs as pneumonia and in some cases can lead to acute respiratory failure. Progression to severe COVID-19 is associated with comorbid disease such as obesity, diabetes mellitus and cardiovascular disease, however data concerning the associated risks of HIV coinfection are still conflicting, with large population studies demonstrating poorer outcomes, whilst smaller, case-controlled studies showing better outcomes. Furthermore, underlying immunopathological processes within the lungs and elsewhere, including interactions with other opportunistic infections (OI), remain largely undefined. Nonetheless, new and repurposed anti-viral therapies and vaccines which have been developed are safe to use in this population, and anti-inflammatory agents are recommended with the caveat that the coexistence of opportunistic infections is considered and excluded. Finally, HIV infected patients remain reliant on good ART adherence practices to maintain HIV viral suppression, and some of these practices were disrupted during the COVID-19 pandemic, putting these patients at further risk for acute and long-term adverse outcomes.

A Review of the Ring Trial Design for Evaluating Ring Interventions for Infectious Diseases

In trials of infectious disease interventions, rare outcomes and unpredictable spatiotemporal variation can introduce bias, reduce statistical power, and prevent conclusive inferences. Spillover effects can complicate inference if individual randomization is used to gain efficiency. Ring trials are a type of cluster-randomized trial that may increase efficiency and minimize bias, particularly in emergency and elimination settings with strong clustering of infection. They can be used to evaluate ring interventions, which are delivered to individuals in proximity to or contact with index cases. We conducted a systematic review of ring trials, compare them with other trial designs for evaluating ring interventions, and describe strengths and weaknesses of each design. Of 849 articles and 322 protocols screened, we identified 26 ring trials, 15 cluster-randomized trials, 5 trials that randomized households or individuals within rings, and 1 individually randomized trial. The most common interventions were postexposure prophylaxis (n = 23) and focal mass drug administration and screening and treatment (n = 7). Ring trials require robust surveillance systems and contact tracing for directly transmitted diseases. For rare diseases with strong spatiotemporal clustering, they may have higher efficiency and internal validity than cluster-randomized designs, in part because they ensure that no clusters are excluded from analysis due to zero cluster incidence. Though more research is needed to compare them with other types of trials, ring trials hold promise as a design that can increase trial speed and efficiency while reducing bias.

Oral Antiviral Treatment for COVID-19: A Comprehensive Review on Nirmatrelvir/Ritonavir

Despite the rapid development of efficient and safe vaccines against COVID-19, the need to confine the pandemic and treat infected individuals on an outpatient basis has led to the approval of oral antiviral agents. Taking into account the viral kinetic pattern of SARS-CoV-2, it is of high importance to intervene at the early stages of the disease. A protease inhibitor called nirmatrelvir coupled with ritonavir (NMV/r), which acts as a CYP3A inhibitor, delivered as an oral formulation, has shown much promise in preventing disease progression in high-risk patients with no need for supplemental oxygen administration. Real-world data seem to confirm the drug combination's efficacy and safety against all viral variants of concern in adult populations. Although, not fully clarified, viral rebound and recurrence of COVID-19 symptoms have been described following treatment; however, more data on potential resistance issues concerning the Mpro gene, which acts as the drug's therapeutic target, are needed. NMV/r has been a gamechanger in the fight against the pandemic by preventing hospitalizations and halting disease severity; therefore, more research on future development and greater awareness on its use are warranted.

Post-exposure Lopinavir-Ritonavir Prophylaxis versus Surveillance for Individuals Exposed to SARS-CoV-2: The COPEP Pragmatic Open-Label, Cluster Randomized Trial

BACKGROUND

Since the beginning of the COVID-19 pandemic, no direct antiviral treatment is effective as post-exposure prophylaxis (PEP). Lopinavir/ritonavir (LPV/r) was repurposed as a potential PEP agent against COVID-19.

METHODS

We conducted a pragmatic open-label, parallel, cluster-randomised superiority trial in four sites in Switzerland and Brazil between March 2020 to March 2021. Clusters were randomised to receive LPV/r PEP (400/100 mg) twice daily for 5 days or no PEP (surveillance). Exposure to SARS-CoV-2 was defined as a close contact of >15 minutes in <2 metres distance or having shared a closed space for ≥2 hours with a person with confirmed SARS-CoV-2 infection. The primary outcome is the occurrence of COVID-19 defined by a SARS-CoV-2 infection (positive oropharyngeal SARS-CoV-2 PCR and/or a seroconversion) and ≥1 compatible symptom within 21 days post-enrolment. ClinicalTrials.gov (Identifier: NCT04364022); Swiss National Clinical Trial Portal: SNCTP 000003732.

FINDINGS

Of 318 participants, 157 (49.4%) were women; median age was 39 (interquartile range, 28-50) years. A total of 209 (179 clusters) participants were randomised to LPV/r PEP and 109 (95 clusters) to surveillance. Baseline characteristics were similar, with the exception of baseline SARS-CoV-2 PCR positivity, which was 3-fold more frequent in the LPV/r arm (34/209 [16.3%] vs 6/109 [5.5%], respectively). During 21-day follow-up, 48/318 (15.1%) participants developed COVID-19: 35/209 (16.7%) in the LPV/r group and 13/109 (11.9%) in the surveillance group (unadjusted hazard ratio 1.44; 95% CI, 0.76-2.73). In the primary endpoint analysis, which was adjuted for baseline imbalance, the hazard ratio for developing COVID-19 in the LPV/r group vs surveillance was 0.60 (95% CI, 0.29-1.26; p =0.18).

INTERPRETATION

The role of LPV/r as PEP for COVID-19 remains unanswered. Although LPV/r over 5 days did not significantly reduce the incidence of COVID-19 in exposed individuals, we observed a change in the directionality of the effect in favour of LPV/r after adjusting for baseline imbalance. LPV/r for this indication merits further testing against SARS-CoV-2 in clinical trials.

FUNDING

Swiss National Science Foundation (project no.: 33IC30_166819) and the Private Foundation of Geneva University Hospitals (Edmond Rothschild (Suisse) SA, Union Bancaire Privée and the Fondation pour la recherche et le traitement médical).