Innovative approaches to COVID-19 medical countermeasure development

BACKGROUND

The COVID-19 pandemic, while unfortunately notable for immense strain and death throughout the world, has also shown great promise in the development of medical countermeasures. As the global scientific community shifted almost entirely towards vaccines, diagnostics and therapeutics, new trial designs most significantly adaptive platform trials, began to be used with greater speed and broader reach. These designs allowed for deploying and investigating new therapeutics, repurposing currently existing therapeutics and flexibly removing or adding additional medications as data appeared in real-time. Moreover, public-private sector partnering occurred at a level not seen before, contributing greatly to the rapid development and deployment of vaccines.

OBJECTIVES

To provide a brief overview of the advances in preventative and therapeutic medical countermeasure development for COVID-19.

METHODS

A narrative review of relevant major medical countermeasure trials was conducted using the date range February 2020-December 2022, representing the period of greatest productivity in research to investigate COVID-19.

RESULTS

Among the most influential trial designs are the adaptive platform designs, which have been applied to the development of initial COVID-19 antivirals, monoclonal antibodies, repurposing of existing immunomodulatory therapy and assisted in the disproof of ineffective medical therapies. Some of the most prominent examples include the REMAP-CAP, RECOVERY and TOGETHER trials.

CONCLUSIONS

Adaptive platform trial designs hold great promise for utility in future pandemics and mass casualty events. Additionally, public-private sectoring is essential for rapid medical countermeasure development and should be further enhanced for future biopreparedness.

Exclusion of pregnant people from emergency vaccine clinical trials: A systematic review of clinical trial protocols and reporting from 2009 to 2019

BACKGROUND

Existing ethics guidance and regulatory requirements emphasize the need for pregnancy-specific safety and efficacy data during the development of vaccines in health emergencies. Our objective was to conduct a systematic review of vaccine clinical trials during active epidemic periods.

METHODS

We searched for Phase II and Phase III vaccine clinical trials initiated during the H1N1 influenza, Middle East Respiratory Syndrome Coronavirus (MERS-CoV), Zika, and Ebola virus disease (EVD) outbreaks from 2009 to 2019. Data were extracted from clinical trial protocols identified in the following registries: ClinicalTrials.gov, Pan African Clinical Trial Registry (PACTR), and all primary registries indicated by the World Health Organization's International Clinical Trials Registry Platform (ICTRP). Published studies from registered clinical trials were located through PubMed. Data was extracted on eligibility criteria and pregnancy outcomes. Data from this study is available in the Center for Open Science Data Repository: https://osf.io/nfk2p/?view_only=47deb3b206724af9b46c9c0c0083a267.

RESULTS

We identified 96 vaccine clinical trial protocols and included 84 in analysis. 5 records were excluded in screening for irrelevant abstracts, 7 were excluded in full-text assessment (1 for a therapeutic drug trial, 3 for enrolling elderly adults only, 3 for enrolling children/adolescents only). There were no eligible trials for MERS-CoV or Zika virus vaccines. Overall, 8 protocols explicitly included pregnant people; of these, 3 were completed trials with published results. Incidental pregnancies and outcomes of pregnant participants were reported in 2 studies, 10 studies reported serious adverse events related to pregnancy without mentioning total incidental pregnancies. A total of 411 recorded pregnancy outcomes were reported, with 293 from the 3 pregnancy-eligible studies with results. 71 serious adverse events pertaining to pregnancy were reported from all clinical trials with results.

CONCLUSION

Pregnant people are underrepresented in vaccine clinical trials conducted during outbreaks, resulting in underreporting of pregnancy-related outcomes and a lack of protection for pregnant people and neonates from infectious diseases.

US Hospital Capacity Managers' Experiences and Concerns Regarding Preparedness for Seasonal Influenza and Influenza-like Illness

IMPORTANCE

The 2017-2018 influenza season in the US was marked by a high severity of illness, wide geographic spread, and prolonged duration compared with recent previous seasons, resulting in increased strain throughout acute care hospital systems.

OBJECTIVE

To characterize self-reported experiences and views of hospital capacity managers regarding the 2017-2018 influenza season in the US.

DESIGN, SETTING, AND PARTICIPANTS

In this qualitative study, semistructured telephone interviews were conducted between April 2018 and January 2019 with a random sample of capacity management administrators responsible for throughput and hospital capacity at short-term, acute care hospitals throughout the US.

MAIN OUTCOMES AND MEASURES

Each participant's self-reported experiences and views regarding high patient volumes during the 2017-2018 influenza season, lessons learned, and the extent of hospitals' preparedness planning for future pandemic events. Interviews were recorded and transcribed and then analyzed using thematic content analysis. Outcomes included themes and subthemes.

RESULTS

A total of 53 key hospital capacity personnel at 53 hospitals throughout the US were interviewed; 39 (73.6%) were women, 48 (90.6%) had a nursing background, and 29 (54.7%) had been in the occupational role for more than 4 years. Participants' experiences were categorized into several domains: (1) perception of strain, (2) effects of influenza and influenza-like illness on staff and patient care, (3) immediate staffing and capacity responses to influenza and influenza-like illness, and (4) future staffing and capacity preparedness for influenza and influenza-like illness. Participants reported experiencing perceived strain associated with concerns about preparedness for seasonal influenza and influenza-like illness as well as concerns about staffing, patient care, and capacity, but future pandemic planning within hospitals was not reported as being a high priority.

CONCLUSIONS AND RELEVANCE

The findings of this qualitative study suggest that during the 2017-2018 influenza season, there were systemic vulnerabilities as well as a lack of hospital preparedness planning for future pandemics at US hospitals. These issues should be addressed given the current coronavirus disease 2019 pandemic.

555. Effectiveness of a Treatment Team on Adherence to Health System Guidelines for Hydroxychloroquine Use During Two Phases of the COVID-19 Epidemic

Background

Our hospital system created system guidelines to standardize care across 24 hospitals for COVID-19 treatment during the pandemic. Guidelines changed over time. Hydroxychloroquine (HCQ) was unrestricted during phase 1, then restricted by pharmacy outside of a randomized clinical trial (RCT) during phase 2 (excepting those ineligible for RCTs).

Methods

This was a prospective study to assess system-wide adherence to COVID-19 treatment guidelines, and to evaluate patient outcomes.

Results

Of 261 patients, median age was 67 years (IQR 56–76); 49% (129/261) were male, and 45% (118/261) required ICU care.

Overall, 47% (122/261) were in phase 1; HCQ was offered to 57% (69/122) during this phase. The rate of HCQ prescription in phase 2 decreased significantly to 10% (14/136), (p < 0.001). Adherence to COVID-19 treatment protocol was 97% (135/139) during phase 2. Mortality was similar in both phases (22% vs 28%, p=0.32), as was median length of stay (8 vs 7 days, p=0.3). Overall 66 patients (25%) died in the hospital; neither non-adherence (p=1) to system guidelines nor receipt of HCQ (p=0.17) were risk factors for death.

Independent predictors of mortality included: new renal replacement therapy (OR 61, 95%CI 6.7–560, p < 0.001), mechanical ventilation (OR 4.9, 95%CI 2.0–11, p < 0.001), abnormal chest X-ray (OR 4.3, 95%CI 1.4–12.6, p =0.009), history of heart failure (OR 3.9, 95%CI 1.5–11, p=0.006), lack of fever on admission (OR 3.5, 95%CI 1.7 -7.6, p =0.001), receipt of corticosteroids (OR 2.7 95%CI 1.1–6.6, p=0.026) and increased age (OR 1.07 per year, 95%CI 1.04–1.1, p < 0.001). Bacterial pneumonia occurred in 8% (21/261), more commonly in those who died (p=0.02). Black patients had a higher race-specific death rate (308 vs 197) per 1000 than white patients (p< 0.001).

Conclusion

During the COVID-19 pandemic, our health system guidelines and pharmacy restrictions were successful in delivering consistent care across hospitals. Restriction of HCQ for COVID-19 treatment to RCTs reduced its use in phase two. Non-adherence to systemic guidelines was infrequent, and not associated with adverse outcomes. A COVID-19 treatment team of physicians and pharmacists can effectively coordinate therapy across hospitals in the setting of rapidly changing guidelines.

Disclosures

J. Ryan Bariola, MD, Infectious Disease Connect (Employee)Mayne Pharma (Advisor or Review Panel member)Merck (Research Grant or Support)

1651. The Impact of the 2017–2018 Influenza Season on Acute Care Hospitals in the United States: A Qualitative Evaluation of Immediate Responses and Future Preparedness

Background

The 2017–2018 influenza season was characterized by high illness severity, wide geographic spread, and prolonged duration compared with recent years in the United States – resulting in an increased number of emergency department evaluations and hospital admissions. The current study explored how US hospitals perceived the impact of influenza during this time period, including effects on patient volumes, ways in which hospitals responded, and how lessons learned were incorporated into future influenza preparedness.

Methods

We conducted semi-structured phone interviews with capacity management personnel in short-term acute care hospitals across the United States. A random hospital sample was created using Centers for Medicare and Medicaid Services annual reports. Hospitals self-identified key informants who were involved with throughput and capacity. The interview guide was developed and pilot tested by a team of clinicians and qualitative researchers, with interviews conducted between April 2018 and January 2019. We performed thematic content analysis to identify how hospitals experienced the 2017–2018 influenza season.

Results

We achieved thematic saturation after 53 interviews. Responses conformed to three thematic domains: impacts on staff and patient care, immediate staffing and capacity responses, and future preparedness (Table 1). Hospitals almost universally reported increased emergency department and inpatient volumes that frequently resulted in strain across the hospital. Strain was created by both increased patient volume and staff shortages due to influenza illness. As strategies to address strain, respondents reported the use of new protocols, new vaccination policies, additional staffing, suspected-influenza treatment areas, and more frequent hospital administration meetings. Many hospitals reported increased diversion time. Despite experiencing high levels of strain, some hospitals reported no changes to their future influenza preparation plans.

Conclusion

Acute care hospitals experienced significant strain as a result of the 2017–2018 influenza season. Hospitals implemented a range of immediate responses to seasonal influenza, but generally did not report future planning specific to influenza.

Disclosures

All authors: No reported disclosures.

2785. Respiratory Viral Panel Testing in Intensive Care Units: Effects on Outcomes

Background

Acute respiratory viral illnesses cause significant morbidity and mortality leading to high healthcare costs. Delayed viral pathogen diagnosis likely contributes to increases in morbidity and mortality. We aimed to analyze: (1) the use of respiratory viral panel (RVP) testing in adults hospitalized to intensive care units (ICUs) with acute respiratory illness (ARI) during flu season; and (2) if RVP testing is associated with improved outcomes.

Methods

Data from adults hospitalized to the ICU with ARI during the 2015–2016, 2016–2017, and 2017–2018 influenza seasons at 3 hospitals participating in the US Hospitalized Adult Influenza Vaccine Effectiveness Network (HAIVEN) study was analyzed. Details of disease severity, underlying health status, and vaccination status were obtained through enrollment interviews and medical records. Clinical RVP results were recorded. Research swabs for influenza (CDC PCR) were performed in all patients who did not have a clinical sample. Multivariate regression was used to estimate the associations between RVP and in-hospital complications.

Results

397 patients were enrolled; 263 (66%) had a clinical RVP done. 25% of patients with ≥ 1 CDC-defined high-risk condition for influenza complications did not have an RVP. 36 (9%) of patients had a positive RVP for flu (1 H1N1, 28 H3, 1 A no subtype, and 6 B). Mean time from onset of symptoms to RVP was 2.25 ± 2.24 days and mean time from ICU admission to RVP was 0.85 ± 1.27 days. 11 (8%) of patients who had only a research swab were positive for flu (1 A no subtype, others H3). 4 (36%) of these patients received oseltamivir. Use of antivirals was significantly more common in patients who had RVPs (68 vs 1%, p

Conclusion

One-third of patients admitted to the ICU with ARI during the flu season did not have an RVP, including 25% of patients with ≥ 1 high-risk condition for influenza complications. Influenza was present in 8% of patients who did not undergo clinical testing and 64% of these patients did not receive antivirals. There is room for improvement in ordering of RVPs in ICUs.

Disclosures

All authors: No reported disclosures.

The start site of the Acanthamoeba castellanii ribosomal RNA transcription unit

The 39S ribosomal RNA (rRNA) precursor has been isolated from Acanthamoeba castellanii. In vitro capping of the isolated RNA verified that it is the primary transcript and identified the 5' nucleotide as pppA. The position of the 5' coding nucleotide on the rRNA repeat unit sequence was identified using Northern blot, R-loop, and S1 nuclease mapping techniques. Dinucleotide priming of an in vitro transcription system stalled because of low initiating nucleotide concentration revealed that ApA maximally stimulates initiation of transcription. All of these results show that the underlined A in the sequence 5'-TATATATAAAGGGAC (RNA-like strand) coincides with the 5' nucleotide of the primary transcript. This identification is compatible with in vitro transcription experiments mapping the promoter for this transcription unit. The initiation sequences of rRNA genes from 14 species are compared, and a weak consensus for the initiator derived: [Formula; see text].

Dihydrocarbazole alkaloids from Aspergillus tubingensis

Investigation of the fungus Aspergillus tubingensis has led to the isolation and identification of two dihydrocarbazole-containing compounds (1 and 2). Details of the purification and structure elucidation of 1 and 2 are described. This is the first known report of dihydrocarbazole-containing compounds to be isolated from a living system.

Inhibition of fungal sphingolipid biosynthesis by rustmicin, galbonolide B and their new 21-hydroxy analogs

The mode of action of the known antifungal macrolides rustmicin (1) and galbonolide B (2) has been determined to be the inhibition of sphingolipid biosynthesis. A large scale fermentation and isolation process was developed for production of large quantities of rustmicin. New 21-hydroxy derivatives of both compounds were isolated from pilot scale fermentations and were also produced by biotransformation of rustmicin and galbonolide B.

An activator of calcium-dependent potassium channels isolated from a medicinal herb

Large-conductance calcium-dependent potassium (maxi-K) channels play an important role in regulating the tone of airway smooth muscle and the release of bronchoconstrictive substances from nerves in the lung. Crude extracts of Desmodium adscendens, a medicinal herb used in Ghana as a treatment for asthma, inhibit binding of monoiodotyrosine charybdotoxin (125I-ChTX) to receptor sites in bovine tracheal smooth muscle membranes that have been shown to be associated with maxi-K channels. Using this assay, three active components have been purified and identified by NMR and MS. Comparison with authentic samples revealed the three active components as the known triterpenoid glycosides dehydrosoyasaponin I (DHS-I), soyasaponin I, and soyasaponin III. The most potent of these compounds, DHS-I, is a partial inhibitor of 125I-ChTX binding (Ki = 120 nM, 62% maximum inhibition). Inhibition of 125I-ChTX binding is primarily due to a decrease in the observed maximum number of binding sites, with a smaller decrease in affinity. DHS-I increases the rate of toxin dissociation from its receptor, suggesting that modulation of ChTX binding occurs through an allosteric mechanism. DHS-I reversibly increases the open probability of maxi-K channels from bovine tracheal smooth muscle incorporated into planar lipid bilayers when applied to the intracellular, but not the extracellular, side of the membrane at concentrations as low as 10 nM. In contrast, DHS-I had no effect on several other types of potassium channels or membrane transporters. This natural product is the first example of a high-affinity activator of calcium-dependent potassium channels and is the most potent known potassium channel opener.

In vitro evidence that eukaryotic ribosomal RNA transcription is regulated by modification of RNA polymerase I

We have utilized a cell-free transcription system from Acanthamoeba castellanii to test the functional activity of RNA polymerase I and transcription initiation factor I (TIF-I) during developmental down regulation of rRNA transcription. The results strongly suggest that rRNA transcription is regulated by modification, probably covalent, of RNA polymerase I: (1) The level of activity of TIF-I in extracts from transcriptionally active and inactive cells is constant. (2) The number of RNA polymerase I molecules in transcriptionally active and inactive cells is also constant. (3) In contrast, though the specific activity of polymerase I on damaged templates remains constant, both crude and purified polymerase I from inactive cells have lost the ability to participate in faithful initiation of rRNA transcription. (4) Polymerase I purified from transcriptionally active cells has the same subunit architecture as enzyme from inactive cells. However, the latter is heat denatured 5 times faster than the active polymerase.

Faithful initiation of ribosomal RNA transcription from cloned DNA by purified RNA polymerase I

A faithful transcription system for ribosomal RNA genes has been developed by using components from the small free-living amoeba Acanthamoeba castellanii. The system utilizes protein-free recombinant DNA as a template and in addition requires a crude cell-free extract containing RNA polymerase I and a transcription initiation factor (TIF-I). The transcript is initiated at the same position as the in vivo precursor ribosomal RNA: templates truncated at various sites downstream of the transcription start site give rise to only the predicted runoff RNA transcripts, and the runoff transcript produced has a 5'-terminus identical with the 5'-terminus of the isolated ribosomal RNA precursor. Faithful initiation can be elicited by the DNA sequence extending from -55 to +19 in the template. Subclones containing this sequence yield only the predicted runoff RNAs regardless of the orientation of this fragment in the cloning vector DNA; thus, only the in vivo sense strand of the template is specifically transcribed in the in vitro system. The system is specific for the RNA polymerase responsible for the transcription of ribosomal RNA genes in vivo. Faithful transcription, like RNA polymerase I from Acanthamoeba, is insensitive to alpha-amanitin inhibition, and transcription is greatly stimulated by highly purified RNA polymerase I but not by RNA polymerases II or III. Conditions for optimal transcription were determined.

Ribosomal ribonucleic acid repeat unit of Acanthamoeba castellanii: cloning and restriction endonuclease map

The repeat unit coding for the precursor to 18S, 5.8S, and 26S ribosomal ribonucleic acids (rRNAs) has been cloned from the free-living soil amoeba Acanthamoeba castellanii. The cloned deoxyribonucleic acid (DNA) was mapped with 11 restriction endonucleases and by R-loop mapping. The entire repeat unit is 12 kbp (kilobase pairs) in length and contains sites for EcoRI, SmaI, BglII, SstI, Bam-HI, PstI, KpnI, HindIII, and XbaI but not for XhoI or SalI. All of the repeat units in the nuclear DNA appear to be identical, and no introns were detected. However, the regions which code for the two RNAs which comprise the 26S RNA are separated by a gap of approximately 200 base pairs. Unlike some other lower eukaryotes, the 5S RNA gene is not linked to this repeat unit. A fragment of the repeat unit which contains the initiation sequence of the putative precursor has been subcloned into pBR322 for use in vitro transcription studies.