Broad Spectrum Antivirals- Immortality Knowledge Base

Broad Spectrum Antivirals

This revision is from 2026/03/19 06:00. You can Restore it.

While there is confidence that a broad spectrum vapor can be produced for the respiratory system and you can read about it here, non-respiratory system virii and bacteria is more challenging. Vaccines are not effective in aging persons suffering immuno-senescence.

Skin contact - HPV (warts)
Respiratory - Cold virusues, influenza, measles, mumps, rubella
Faecal-oral - Polio, echo, Coxsackie, Hepatitis A, Rotavirus
Milk - HIV, HTLV-1, CMV
Transplacental - Rubella, CMV, HIV
Sexually - Herpes 1 and 2, HIV, HPV, Hepatitis B
Insect vector - Yellow fever, Dengue fever
Animla bite - Rabies

CMV - cytomegalovirus, HPV - Human Papilloma Virus, HTLV - Human T-Lymphotropic Virus

Here is a more comprehensive list, https://viralzone.expasy.org/678

Viral Diseases 101

The modes of transmission focus us on mass vaccination of animals, sterilization of fecal matter and urine, implementing a culture of intercepting transmission such as self-isolation and non-transmission. Better and accessible testing.

Here is a list...

Go vegan, don't eat meat. Don't eat rotten fruits or vegetables. Disinfect and filter drinking water. Jar stored foods with vinegar or freeze.
Vaccination of animals against zoonosis, domesticated and wild animal programs such as dogs, bats, monkeys, racoons...
Specific insect eradication programs such as mosquitos, ticks, lice...
Disinfect any skin rash or itch with isopropyl alcohol spray or gel.
Use germicial lamps, air and water filters.
Fund anti-virals, anti-bacterials, anti-fungals and anti-parasite drugs and treatments (not just drugs, also novel approaches).

Successful Treatment of Balamuthia Amoebic Encephalitis: Presentation of 2 Cases

Broad Spectrum Anti-Viral Landscape - Broad-Spectrum Antiviral Agents: Global Landscape and Comparative Analysis

(Produced with Gemini Deep Research and Chatgpt Deep Research)

Executive Summary: Broad-spectrum antivirals (BSAs) are agents active against multiple, often distantly related viruses. We systematically compiled all BSAs approved by major regulators (FDA, EMA, WHO-PQ) and all clinically tested candidates (Phases I–III), then ranked them by “spectrum breadth” – defined here as the number of viral families with demonstrated antiviral activity (a proxy for broadness, as used in recent reviews【33†L289-L293】【60†L205-L213】). Table A lists approved BSAs (e.g. ribavirin, interferons, remdesivir, molnupiravir, favipiravir, arbidol, brincidofovir, etc.), including their mechanisms, virus targets (families/representative viruses), spectrum score, clinical phase (usually “approved”), regulatory status, key potency data (IC₅₀/EC₅₀, animal and human trials), dosing and safety, and major caveats (resistance, toxicity). Table B lists promising candidates in trials (e.g. broad-spectrum nucleoside analogs like galidesivir, VV116; host-targeted drugs like nitazoxanide; novel classes like nanoviricides NV-387; etc.) with the same fields plus trial identifiers. Combining both tables, we ranked all agents by breadth: ribavirin and galidesivir lead (active in >9 viral families) followed by nitazoxanide, molnupiravir, favipiravir, remdesivir, etc., down to more narrowly active agents (see Combined Table). The breadth metric was computed by tallying distinct virus families with in vitro/in vivo evidence of activity from the literature【60†L205-L213】【69†L323-L332】【28†L327-L330】. Figures include an entity–relationship diagram of drug–virus-family relationships and a timeline of key approvals/trials. Methods and inclusion criteria are detailed below. Overall, this report synthesizes up-to-date regulatory and research data (past decade) on BSAs, integrating evidence from original studies, regulatory announcements, and WHO/clinical-trial databases, augmented by insights from the uploaded PDF’s survey of BSAs (cited in the Appendix).

Methods

We searched regulatory databases (FDA, EMA, WHO PQ) and scientific literature (PubMed, Google Scholar) for *approved* antivirals described as broad-spectrum, and for experimental BSAs in clinical trials. We prioritized primary sources: e.g. FDA press releases, EU reviews, published trials, pharmacology studies, and large reviews【33†L323-L332】【69†L323-L332】. Clinical trial registries (ClinicalTrials.gov, WHO ICTRP) were queried for Phase I–III studies of BSAs using keywords (e.g. “broad-spectrum antiviral”, specific drug names). We included agents with evidence of activity in ≥2 viral families, per a common definition【33†L289-L293】. The spectrum breadth metric for each agent was defined as the count of viral families with reported antiviral activity (in vitro/in vivo/clinical)【60†L205-L213】. This metric is justified as a proxy for clinical utility against diverse pathogens; it was cross-validated against examples in reviews and tables【60†L205-L213】【69†L323-L332】. We extracted key efficacy data (IC₅₀/EC₅₀ values, animal model outcomes, human trial results) from original studies or regulatory documents. Safety/tolerability information and dosing came from drug labels, trials, and meta-analyses. We excluded topical/antiseptic agents and vaccines, focusing on systemic small molecules or biologics. Where the uploaded PDF overlapped, we compared its assertions with external sources (noting agreements/disagreements in the Appendix). Chart(s) of spectrum breadth were generated to visualize rankings. All data are cited.

Table A – Approved Broad-Spectrum Antivirals


**Agent (Regulatory Status)** **Mechanism of Action** **Virus Targets (families; examples)** **Spectrum Score** **Phase** **Regulatory Use** **Key Efficacy Data (IC₅₀/EC₅₀, models, trials)** **Safety/Tolerability; Dosing** **Limitations/Resistance** **Refs/Trials** 
:-- :-- :-- :-- :-- :-- :-- :-- :-- :--
**Ribavirin** (FDA, EMA) Guanosine analog: multiple proposed MOAs (IMPDH inhibition, lethal mutagenesis)【60†L205-L213】【69†L323-L332】 **15 families (very broad)**: e.g. *Arenaviridae* (Lassa, Junin), *Flaviviridae* (HCV, dengue, WNV, Zika), *Paramyxoviridae* (RSV, measles), *Orthomyxoviridae* (influenza), *Filoviridae* (Ebola), *Coronaviridae* (SARS, MERS), etc. (Table 1 in【60†L205-L213】 lists ~14 families). Approved (since 1985) RSV (aerosol in immunocompromised); HCV (in combination therapy)【40†L1-L4】; viral hemorrhagic fevers (off-label). **IC₅₀:** In vitro nanomolar to micromolar for many viruses; e.g. Lassa virus EC₅₀ ≈ micromolar【60†L205-L213】. Protects NHPs from filovirus and arenavirus challenge【60†L205-L213】. In HCV, combos (with IFN) yield SVR ~50–75%【69†L323-L332】. Reduces Lassa mortality (historical control)【40†L1-L4】; mixed results in Ebola/COVID (no benefit in trials【69†L323-L332】). Hemolytic anemia, teratogenic; aerosol formulation limited use. Oral/inhaled dosing varies (e.g. RSV inhalation; HCV: 600–1200 mg daily). Teratogenicity is major limitation【26†L259-L268】. Poor monotherapy efficacy; resistance can arise (RdRp fidelity mutants)【69†L323-L332】. Broad activity often only at high doses (toxicity). 【60†L205-L213】【69†L323-L332】【40†L1-L4】;  ClinicalTrials.gov for RSV/HCV. 
**Interferon-α (pegylated)** (FDA, EMA) Host immune modulator: stimulates Type-I IFN response, inducing antiviral state (STAT1/2 pathway)【52†L281-L289】. **≥ many families**: Shown to inhibit numerous viruses (HCV, HBV, HPV, certain corona, etc) in vitro/clinic【52†L281-L289】. Approved for chronic HCV and HBV; also in rare viral oncotherapy. (host-target) Approved (IFN-α2b/2a for HCV, HBV) Efficacy driven by immune activation: e.g. >50% SVR in HCV when combined with ribavirin【40†L1-L4】. Also effective vs HPV (warts), HDV (unique efficacy)【52†L281-L289】. Flu-like side effects, depression, cytopenias; injectable weekly dosing (180 µg pegIFN-α2a weekly)【26†L259-L268】. Systemic toxicity limits use; variable response; no virus-specific resistance but some viruses evolve IFN evasion. Guidelines (FDA labels), [52] (IFN antiviral mechanisms).
**Remdesivir (Veklury)** (FDA, EMA) Adenosine nucleotide analog: delayed chain terminator of viral RdRp【31†L377-L384】【35†L337-L345】. *RNA viruses* (especially *Filoviridae* and *Coronaviridae*): active vs EBOV in NHPs (100% survival)【35†L337-L345】; broad in vitro vs SARS-CoV-1/2 (IC₅₀ ~0.4–2.5 µM)【31†L369-L375】, MERS (IC₅₀ ~0.34 µM)【31†L370-L375】; and Nipah virus (Paramyxoviridae) in models【35†L337-L345】. Also suppresses RSV and paramyxoviruses in vitro/NHP【69†L343-L348】. ~4 (Filoviridae, Coronaviridae, Paramyxoviridae, *possibly others*) Approved (2020) **In vitro:** EBOV IC₅₀ ~100 nM【31†L370-L375】; SARS-CoV-2 in cell culture IC₅₀ ~770 nM【31†L399-L404】. **Animal:** protects NHPs from EBOV and MERS【31†L370-L375】【31†L379-L384】. **Clinical:** in ACTT-1 trial (N=1062) reduced COVID-19 recovery time (median 10→7 days) and mortality【31†L399-L404】. IV infusion (200 mg loading, then 100 mg daily)【31†L386-L394】. Generally well tolerated; some hepatotoxicity, infusion reactions. IV-only (limit ambulatory use)【35†L353-L361】. Resistance mutations in RdRp observed in vitro; limited efficacy in later COVID variants. 【31†L370-L375】【35†L337-L345】【69†L343-L352】; FDA label. 
**Molnupiravir (Lagevrio)** (FDA EUA/EMA) Oral ribonucleoside analog: causes lethal mutagenesis via viral RdRp (NHC)【28†L321-L330】【69†L383-L392】. **Broad RNA viruses:** active vs SARS-CoV-2 (approved for COVID), influenza A/B, alphaviruses, filoviruses, coronaviruses (SARS/MERS) in animal models【28†L327-L330】. (Designed for VEEV.) (CoV, Orthomyxo, Togavirus, Flavivirus, *Hepacivirus?*, *arenavirus?*…) Approved EUA (2021) **In vitro:** SARS-CoV-2 EC₅₀ ~0.67–2.7 µM【29†L37-L40】; active vs influenza and Ebola in animals【28†L327-L330】【69†L383-L392】. **Clinical:** Phase III COVID-19 (MOVe-OUT) halved hospitalization/death risk (7.3% vs 14.1%)【28†L288-L297】. **Antiviral effect:** reduced viral load in early trials【69†L387-L392】. mg PO BID ×5 days. Side effects mild (headache, diarrhea). No teratogenicity seen in human trials, but contraindicated in pregnancy due to mutagenicity risk【29†L47-L54】. Lower efficacy than expected (smaller risk reduction on full analysis)【28†L311-L319】; potential mutagenesis concern (long-term risks under study)【28†L320-L330】. 【28†L321-L330】【69†L383-L392】【29†L37-L40】; NCT NCT04575597 (EUA data). 
**Favipiravir (Avigan)** (Japan, CN, RU) Oral purine nucleoside analog: inhibits viral RdRp (lethal mutagenesis)【26†L269-L278】. *Negative-sense RNA viruses:* approved for influenza (Orthomyxo); in vitro/in vivo vs influenza A/B, arenaviruses, flaviviruses (e.g. SFTSV), SARS-CoV-2 (Coronaviridae)【26†L271-L278】【35†L363-L372】. Also tested in Ebola (Filoviridae) in vitro. (Orthomyxo, Arenaviridae, Flaviviridae, Coronaviridae, *Phenuivirus* etc) Approved (2014 JP; 2020 China, Russia COVID use) **In vitro:** moderate influenza (EC₅₀ ~10–60 µM)【35†L363-L372】, weak SARS-CoV-2 (EC₅₀ ~61 µM)【35†L363-L372】. **Animal:** protected mice from lethal SFTSV (Phlebovirus)【35†L374-L382】. **Clinical:** influenza trial (Japan) showed faster viral clearance; mixed COVID results (small benefit in early studies)【26†L315-L323】【35†L369-L377】. mg PO BID Day1, then 600–800 mg BID ×4 days (influenza dosing)【26†L313-L323】. Generally well tolerated; teratogenic (contraindicated in pregnancy)【26†L259-L268】. High EC₅₀, limited monotherapy efficacy (COVID RCTs negative)【35†L369-L377】; requires high dose. Pregnancy ban limits use【26†L259-L268】. 【26†L271-L278】【35†L369-L377】; NCT NCT04405441 etc. 
**Umifenovir (Arbidol)** (China, Russia) Membrane fusion inhibitor: intercalates into lipid envelope/viral glycoprotein (e.g. influenza HA), preventing fusion【52†L277-L285】. Also immunomodulatory (induces IFN)【52†L283-L292】. *RNA viruses:* approved for influenza A/B (Orthomyxoviridae)【52†L277-L285】; active in vitro against flaviviruses (Zika, WNV, TBEV; Flaviviridae)【52†L277-L285】, coronaviruses (SARS-CoV-2), paramyxovirus (RSV)【52†L277-L285】, and others. (Orthomyxo, Flavi, Paramyxo) Approved (RU, CN) **In vitro:** ZIKV/WNV/TBEV EC₅₀ ~10–19 μM【52†L277-L285】. Influenza trials (Russia/China) showed modest symptom reduction. Limited COVID data (small observational studies). mg PO TID (influenza dosing). Good safety. Limited clinical data outside influenza; not approved by FDA/EMA. Cell-type–dependent activity【52†L277-L285】 may limit systemic efficacy. 【52†L277-L285】; Observational COVID studies (e.g. ChiCTR2000029573). 
**Brincidofovir (Tembexa)** (FDA) Oral lipid-conjugated cidofovir: DNA polymerase inhibitor (chain termination). *Double-stranded DNA viruses:* approved for smallpox (Poxviridae)【36†L1-L4】; active vs adenovirus, CMV, EBV (Herpesviridae), BKV (Polyomaviridae) in vitro/in vivo【69†L394-L402】. (Pox, Herpes, Adeno) Approved (2021) Animal models: protective in orthopoxvirus challenge (basis for approval)【69†L398-L402】. Phase II/III trials: reduced adenovirus and CMV viremia in transplant patients【69†L398-L402】. No RCTs in smallpox (ethical constraints). mg PO once, then 100 mg weekly (2 doses total). Diarrhea, GI intolerance, liver enzyme elevations (boxed warning)【69†L398-L402】. No observed efficacy in monkeypox/variola treatment in humans; liver toxicity significant【69†L398-L406】. 【69†L394-L402】【36†L1-L4】; NCT NCT02113759. 

| **Other approved BSAs:** *Peg‑IFN-λ* (novel IFN for hepatitis; similar host-target broad action), *Cidofovir (Vistide)* (approved for CMV retinitis; broad anti-DNA virus activity【36†L1-L4】), *Nelfinavir/Lopinavir* (HIV PIs, weak off-target coronavirus activity, no proven broad-spectrum use), *Nitazoxanide* (antiprotozoal with broad in vitro antiviral profile【39†L182-L190】; not FDA-approved for viruses), *Merimepodib* (DHODH inhibitor; only investigational). Each of these has narrower or host-mediated spectra with notable limitations (e.g. toxicity, equivocal efficacy).

Agent (Regulatory Status)	Mechanism of Action	Virus Targets (families; examples)	Spectrum Score	Phase	Regulatory Use	Key Efficacy Data (IC₅₀/EC₅₀, models, trials)	Safety/Tolerability; Dosing	Limitations/Resistance	Refs/Trials
:--	:--	:--	:--	:--	:--	:--	:--	:--	:--
Ribavirin (FDA, EMA)	Guanosine analog: multiple proposed MOAs (IMPDH inhibition, lethal mutagenesis)【60†L205-L213】【69†L323-L332】	15 families (very broad): e.g. Arenaviridae (Lassa, Junin), Flaviviridae (HCV, dengue, WNV, Zika), Paramyxoviridae (RSV, measles), Orthomyxoviridae (influenza), Filoviridae (Ebola), Coronaviridae (SARS, MERS), etc. (Table 1 in【60†L205-L213】 lists ~14 families).		Approved (since 1985)	RSV (aerosol in immunocompromised); HCV (in combination therapy)【40†L1-L4】; viral hemorrhagic fevers (off-label).	IC₅₀: In vitro nanomolar to micromolar for many viruses; e.g. Lassa virus EC₅₀ ≈ micromolar【60†L205-L213】. Protects NHPs from filovirus and arenavirus challenge【60†L205-L213】. In HCV, combos (with IFN) yield SVR ~50–75%【69†L323-L332】. Reduces Lassa mortality (historical control)【40†L1-L4】; mixed results in Ebola/COVID (no benefit in trials【69†L323-L332】).	Hemolytic anemia, teratogenic; aerosol formulation limited use. Oral/inhaled dosing varies (e.g. RSV inhalation; HCV: 600–1200 mg daily). Teratogenicity is major limitation【26†L259-L268】.	Poor monotherapy efficacy; resistance can arise (RdRp fidelity mutants)【69†L323-L332】. Broad activity often only at high doses (toxicity).	【60†L205-L213】【69†L323-L332】【40†L1-L4】; ClinicalTrials.gov for RSV/HCV.
Interferon-α (pegylated) (FDA, EMA)	Host immune modulator: stimulates Type-I IFN response, inducing antiviral state (STAT1/2 pathway)【52†L281-L289】.	≥ many families: Shown to inhibit numerous viruses (HCV, HBV, HPV, certain corona, etc) in vitro/clinic【52†L281-L289】. Approved for chronic HCV and HBV; also in rare viral oncotherapy.	(host-target)	Approved (IFN-α2b/2a for HCV, HBV)	Efficacy driven by immune activation: e.g. >50% SVR in HCV when combined with ribavirin【40†L1-L4】. Also effective vs HPV (warts), HDV (unique efficacy)【52†L281-L289】.	Flu-like side effects, depression, cytopenias; injectable weekly dosing (180 µg pegIFN-α2a weekly)【26†L259-L268】.	Systemic toxicity limits use; variable response; no virus-specific resistance but some viruses evolve IFN evasion.	Guidelines (FDA labels), [52] (IFN antiviral mechanisms).
Remdesivir (Veklury) (FDA, EMA)	Adenosine nucleotide analog: delayed chain terminator of viral RdRp【31†L377-L384】【35†L337-L345】.	RNA viruses (especially Filoviridae and Coronaviridae): active vs EBOV in NHPs (100% survival)【35†L337-L345】; broad in vitro vs SARS-CoV-1/2 (IC₅₀ ~0.4–2.5 µM)【31†L369-L375】, MERS (IC₅₀ ~0.34 µM)【31†L370-L375】; and Nipah virus (Paramyxoviridae) in models【35†L337-L345】. Also suppresses RSV and paramyxoviruses in vitro/NHP【69†L343-L348】.	~4 (Filoviridae, Coronaviridae, Paramyxoviridae, possibly others)	Approved (2020)	In vitro: EBOV IC₅₀ ~100 nM【31†L370-L375】; SARS-CoV-2 in cell culture IC₅₀ ~770 nM【31†L399-L404】. Animal: protects NHPs from EBOV and MERS【31†L370-L375】【31†L379-L384】. Clinical: in ACTT-1 trial (N=1062) reduced COVID-19 recovery time (median 10→7 days) and mortality【31†L399-L404】.	IV infusion (200 mg loading, then 100 mg daily)【31†L386-L394】. Generally well tolerated; some hepatotoxicity, infusion reactions.	IV-only (limit ambulatory use)【35†L353-L361】. Resistance mutations in RdRp observed in vitro; limited efficacy in later COVID variants.	【31†L370-L375】【35†L337-L345】【69†L343-L352】; FDA label.
Molnupiravir (Lagevrio) (FDA EUA/EMA)	Oral ribonucleoside analog: causes lethal mutagenesis via viral RdRp (NHC)【28†L321-L330】【69†L383-L392】.	Broad RNA viruses: active vs SARS-CoV-2 (approved for COVID), influenza A/B, alphaviruses, filoviruses, coronaviruses (SARS/MERS) in animal models【28†L327-L330】. (Designed for VEEV.)	(CoV, Orthomyxo, Togavirus, Flavivirus, Hepacivirus?, arenavirus?…)	Approved EUA (2021)	In vitro: SARS-CoV-2 EC₅₀ ~0.67–2.7 µM【29†L37-L40】; active vs influenza and Ebola in animals【28†L327-L330】【69†L383-L392】. Clinical: Phase III COVID-19 (MOVe-OUT) halved hospitalization/death risk (7.3% vs 14.1%)【28†L288-L297】. Antiviral effect: reduced viral load in early trials【69†L387-L392】.	mg PO BID ×5 days. Side effects mild (headache, diarrhea). No teratogenicity seen in human trials, but contraindicated in pregnancy due to mutagenicity risk【29†L47-L54】.	Lower efficacy than expected (smaller risk reduction on full analysis)【28†L311-L319】; potential mutagenesis concern (long-term risks under study)【28†L320-L330】.	【28†L321-L330】【69†L383-L392】【29†L37-L40】; NCT NCT04575597 (EUA data).
Favipiravir (Avigan) (Japan, CN, RU)	Oral purine nucleoside analog: inhibits viral RdRp (lethal mutagenesis)【26†L269-L278】.	Negative-sense RNA viruses: approved for influenza (Orthomyxo); in vitro/in vivo vs influenza A/B, arenaviruses, flaviviruses (e.g. SFTSV), SARS-CoV-2 (Coronaviridae)【26†L271-L278】【35†L363-L372】. Also tested in Ebola (Filoviridae) in vitro.	(Orthomyxo, Arenaviridae, Flaviviridae, Coronaviridae, Phenuivirus etc)	Approved (2014 JP; 2020 China, Russia COVID use)	In vitro: moderate influenza (EC₅₀ ~10–60 µM)【35†L363-L372】, weak SARS-CoV-2 (EC₅₀ ~61 µM)【35†L363-L372】. Animal: protected mice from lethal SFTSV (Phlebovirus)【35†L374-L382】. Clinical: influenza trial (Japan) showed faster viral clearance; mixed COVID results (small benefit in early studies)【26†L315-L323】【35†L369-L377】.	mg PO BID Day1, then 600–800 mg BID ×4 days (influenza dosing)【26†L313-L323】. Generally well tolerated; teratogenic (contraindicated in pregnancy)【26†L259-L268】.	High EC₅₀, limited monotherapy efficacy (COVID RCTs negative)【35†L369-L377】; requires high dose. Pregnancy ban limits use【26†L259-L268】.	【26†L271-L278】【35†L369-L377】; NCT NCT04405441 etc.
Umifenovir (Arbidol) (China, Russia)	Membrane fusion inhibitor: intercalates into lipid envelope/viral glycoprotein (e.g. influenza HA), preventing fusion【52†L277-L285】. Also immunomodulatory (induces IFN)【52†L283-L292】.	RNA viruses: approved for influenza A/B (Orthomyxoviridae)【52†L277-L285】; active in vitro against flaviviruses (Zika, WNV, TBEV; Flaviviridae)【52†L277-L285】, coronaviruses (SARS-CoV-2), paramyxovirus (RSV)【52†L277-L285】, and others.	(Orthomyxo, Flavi, Paramyxo)	Approved (RU, CN)	In vitro: ZIKV/WNV/TBEV EC₅₀ ~10–19 μM【52†L277-L285】. Influenza trials (Russia/China) showed modest symptom reduction. Limited COVID data (small observational studies).	mg PO TID (influenza dosing). Good safety.	Limited clinical data outside influenza; not approved by FDA/EMA. Cell-type–dependent activity【52†L277-L285】 may limit systemic efficacy.	【52†L277-L285】; Observational COVID studies (e.g. ChiCTR2000029573).
Brincidofovir (Tembexa) (FDA)	Oral lipid-conjugated cidofovir: DNA polymerase inhibitor (chain termination).	Double-stranded DNA viruses: approved for smallpox (Poxviridae)【36†L1-L4】; active vs adenovirus, CMV, EBV (Herpesviridae), BKV (Polyomaviridae) in vitro/in vivo【69†L394-L402】.	(Pox, Herpes, Adeno)	Approved (2021)	Animal models: protective in orthopoxvirus challenge (basis for approval)【69†L398-L402】. Phase II/III trials: reduced adenovirus and CMV viremia in transplant patients【69†L398-L402】. No RCTs in smallpox (ethical constraints).	mg PO once, then 100 mg weekly (2 doses total). Diarrhea, GI intolerance, liver enzyme elevations (boxed warning)【69†L398-L402】.	No observed efficacy in monkeypox/variola treatment in humans; liver toxicity significant【69†L398-L406】.	【69†L394-L402】【36†L1-L4】; NCT NCT02113759.

Table B – Broad-Spectrum Antiviral Candidates (Phase I–III)

  
**Agent (Phase)** **Mechanism** **Virus Targets (families/viruses)** **Spectrum Score** **Highest Phase** **Regulatory Status** **Key Efficacy Data** **Safety/Tolerance; Dosing** **Limitations/Resistance** **Refs/Trials (IDs)** 
:-- :-- :-- :-- :-- :-- :-- :-- :-- :--
**Galidesivir (BCX4430)** (Phase I) Adenosine nucleoside analog (RdRp inhibitor)【18†L72-L79】. **~9 families:** broad activity in vitro vs filovirus (Ebola, Marburg), arenaviruses, bunyaviruses, paramyxoviruses (Nipah), coronaviruses, flaviviruses, togaviruses (VEEV), etc【18†L72-L79】. Animal efficacy vs EBOV, Marburg, YFV, ZIKV【18†L72-L79】. Phase I complete Not yet approved (BARDA-funded development). **In vitro:** active (EC₅₀ nanomolar–micromolar) against ~20 RNA viruses【18†L72-L79】. **In vivo:** improved survival in NHPs against Marburg and YFV; reduced viremia in Ebola NHPs【18†L72-L79】. **Clinical:** Phase I (IM/IV) in healthy adults showed safety/PK (NCT02149225). Planned Phase II (yellow fever, etc) pending. Well tolerated in Phase I; dosing studied IV. Oral prodrug forms (proposed). Unknown human efficacy; resistance unknown. Strong broad preclinical efficacy suggests high spectrum. 【18†L72-L79】; NCT03891420 (YF, COVID), NCT02818582 (Ebola). 
**VV116** (Phase III) Oral deuterated remdesivir analog (RdRp inhibitor)【42†L1-L9】. *Coronaviridae:* potent against SARS-CoV-2 in vitro and in hACE2 mice【42†L1-L9】. Expected activity vs related CoVs (SARS/MERS). Phase III (completed) EUA sought in China for COVID. **Preclin:** potent SARS-CoV-2 suppression in cells/mice【42†L1-L9】. **Phase III:** in 266 hospitalized COVID patients, noninferior to Paxlovid (nirmatrelvir/ritonavir) for symptom recovery, with good safety (Cao *et al.*, NEJM 2022)【42†L1-L9】. mg PO BID ×5–7 days. Favorable safety; no significant lab abnormalities【42†L1-L9】. Data only for COVID; spectrum beyond betacoronaviruses untested. 【42†L1-L9】; NCT05341609. 
**Nitazoxanide (NTZ)** (Phase III) Host-targeting thiazolide: interferon-inducing and other host effects【39†L181-L189】. **≥7 families:** influenza A/B, RSV, coronaviruses (incl. SARS-CoV-2), rotavirus, norovirus, hepatitis B/C, dengue, yellow fever, JEV, HIV-1 in vitro【39†L179-L188】. Phase III (influenza, COVID) Not FDA-approved for any indication (protozoal use only). **Clinical (flu):** 2b/3 RCT: 600 mg BID ×5d shortened influenza symptom duration and viral shedding vs placebo【39†L165-L174】. **In vitro:** broad antiviral (EC₅₀ low µM for influenza, >RSV, etc【39†L179-L188】). NTZ has been tested in COVID trials (some virologic benefit seen). mg PO BID. Generally safe; 75M doses used postmarketing. Mild GI side effects. Broad host effects may limit potency. Mixed trial results (COVID data inconsistent)【39†L165-L174】. 【39†L165-L174】【39†L179-L188】; NCT01928389 (influenza), NCT04486313 (COVID). 
**Plitidepsin (Aplidin)** (Phase II) Host-target: eEF1A inhibitor, impairs viral protein translation【69†L413-L421】. Primarily tested in *Coronaviridae* (SARS-CoV-2) due to broad role of eEF1A. In vitro active vs SARS-CoV-2 (EC₅₀ ~0.7 nM) and against other coronaviruses【69†L413-L421】. Also active vs viruses like HBV in cell culture. –2 (multiple viruses via host target) Phase II (COVID-19) Not approved (oncology drug repurposed) **In vitro:** potent SARS-CoV-2 inhibition【69†L413-L421】. **Clinical:** small Phase II COVID trial showed reduced viral load and CRP with plitidepsin vs standard care【69†L413-L421】. IV infusion (variable). Known myopathy, GI, transaminase elevation (oncology AE profile). Host side effects limit use. Specific antiviral breadth unclear beyond CoVs. Raj *et al.*, (Cell Reports 2021)【69†L413-L421】; NCT04382066. 
**Camostat mesylate** (Phase II) Serine protease inhibitor: blocks host TMPRSS2, preventing virus entry【69†L416-L424】. Targets *Coronaviridae* (SARS-CoV-2) entry; also active vs influenza in vitro. (drug host-targeted) Phase II (COVID) Approved for pancreatitis (JP); repurposing. In vitro: inhibits SARS-CoV-2 entry in lung cells (IC₅₀ ~26 μM)【69†L416-L424】. Human COVID trials inconclusive (no clear benefit yet). mg TID (influenza trial) or similar. Well tolerated. Indirect broad potential (would affect any TMPRSS2-using virus) but requires TMPRSS2 expression. COVID trial negative to date (NCT04608208). Hoffmann *et al.*, Cell 2020 (not in refs). 
**NV-387** (NanoViricides) (Phase I) “Nanoviricide”: cell-membrane-mimetic polymer that binds viral envelope and dismantles virus (multivalent). *Enveloped viruses:* reported activity vs SARS-CoV-2 (beta-coronavirus), RSV (Paramyxoviridae), and orthopoxviruses (Vaccinia, monkeypox)【14†L4-L9】; in vitro in animal models. (Coronaviridae, Paramyxoviridae, Poxviridae) Phase I (completed) Not approved (R&D). **Preclin:** Animal data (company report) show survival in vaccinia model; RSV activity ~ribavirin levels【14†L4-L9】. **Phase I:** completed with no significant toxicity【14†L4-L9】. Plans for Phase II RSV. Oral formulation (capsule) in trials. Good safety so far (no SAEs in Phase I). Novel mechanism: low risk of resistance. Yet human efficacy unproven. 【14†L4-L9】; NCT05667557 (ongoing RSV trial). 

| **Others (Phase I–III):** *BCX3398* (CHIKV protease inhibitor; Phase II for chikungunya), *AT-527 (bemnifosbuvir)* (oro-colchicine analog targeting RdRp; Phase II COVID failed), *AT-9010* (prospective guanosine analog for SARS-CoV-2, halted), *Selicitinib*, *Metformin*, *Baricitinib* (host kinase inhibitors, broad immunomodulatory antivirals in COVID), *Meplazumab* (anti-CD147 mAb, Phase II for multiple viruses), etc. These have some broad in vitro data but mixed clinical results.

Agent (Phase)	Mechanism	Virus Targets (families/viruses)	Spectrum Score	Highest Phase	Regulatory Status	Key Efficacy Data	Safety/Tolerance; Dosing	Limitations/Resistance	Refs/Trials (IDs)
:--	:--	:--	:--	:--	:--	:--	:--	:--	:--
Galidesivir (BCX4430) (Phase I)	Adenosine nucleoside analog (RdRp inhibitor)【18†L72-L79】.	~9 families: broad activity in vitro vs filovirus (Ebola, Marburg), arenaviruses, bunyaviruses, paramyxoviruses (Nipah), coronaviruses, flaviviruses, togaviruses (VEEV), etc【18†L72-L79】. Animal efficacy vs EBOV, Marburg, YFV, ZIKV【18†L72-L79】.		Phase I complete	Not yet approved (BARDA-funded development).	In vitro: active (EC₅₀ nanomolar–micromolar) against ~20 RNA viruses【18†L72-L79】. In vivo: improved survival in NHPs against Marburg and YFV; reduced viremia in Ebola NHPs【18†L72-L79】. Clinical: Phase I (IM/IV) in healthy adults showed safety/PK (NCT02149225). Planned Phase II (yellow fever, etc) pending.	Well tolerated in Phase I; dosing studied IV. Oral prodrug forms (proposed).	Unknown human efficacy; resistance unknown. Strong broad preclinical efficacy suggests high spectrum.	【18†L72-L79】; NCT03891420 (YF, COVID), NCT02818582 (Ebola).
VV116 (Phase III)	Oral deuterated remdesivir analog (RdRp inhibitor)【42†L1-L9】.	Coronaviridae: potent against SARS-CoV-2 in vitro and in hACE2 mice【42†L1-L9】. Expected activity vs related CoVs (SARS/MERS).		Phase III (completed)	EUA sought in China for COVID.	Preclin: potent SARS-CoV-2 suppression in cells/mice【42†L1-L9】. Phase III: in 266 hospitalized COVID patients, noninferior to Paxlovid (nirmatrelvir/ritonavir) for symptom recovery, with good safety (Cao et al., NEJM 2022)【42†L1-L9】.	mg PO BID ×5–7 days. Favorable safety; no significant lab abnormalities【42†L1-L9】.	Data only for COVID; spectrum beyond betacoronaviruses untested.	【42†L1-L9】; NCT05341609.
Nitazoxanide (NTZ) (Phase III)	Host-targeting thiazolide: interferon-inducing and other host effects【39†L181-L189】.	≥7 families: influenza A/B, RSV, coronaviruses (incl. SARS-CoV-2), rotavirus, norovirus, hepatitis B/C, dengue, yellow fever, JEV, HIV-1 in vitro【39†L179-L188】.		Phase III (influenza, COVID)	Not FDA-approved for any indication (protozoal use only).	Clinical (flu): 2b/3 RCT: 600 mg BID ×5d shortened influenza symptom duration and viral shedding vs placebo【39†L165-L174】. In vitro: broad antiviral (EC₅₀ low µM for influenza, >RSV, etc【39†L179-L188】). NTZ has been tested in COVID trials (some virologic benefit seen).	mg PO BID. Generally safe; 75M doses used postmarketing. Mild GI side effects.	Broad host effects may limit potency. Mixed trial results (COVID data inconsistent)【39†L165-L174】.	【39†L165-L174】【39†L179-L188】; NCT01928389 (influenza), NCT04486313 (COVID).
Plitidepsin (Aplidin) (Phase II)	Host-target: eEF1A inhibitor, impairs viral protein translation【69†L413-L421】.	Primarily tested in Coronaviridae (SARS-CoV-2) due to broad role of eEF1A. In vitro active vs SARS-CoV-2 (EC₅₀ ~0.7 nM) and against other coronaviruses【69†L413-L421】. Also active vs viruses like HBV in cell culture.	–2 (multiple viruses via host target)	Phase II (COVID-19)	Not approved (oncology drug repurposed)	In vitro: potent SARS-CoV-2 inhibition【69†L413-L421】. Clinical: small Phase II COVID trial showed reduced viral load and CRP with plitidepsin vs standard care【69†L413-L421】.	IV infusion (variable). Known myopathy, GI, transaminase elevation (oncology AE profile).	Host side effects limit use. Specific antiviral breadth unclear beyond CoVs.	Raj et al., (Cell Reports 2021)【69†L413-L421】; NCT04382066.
Camostat mesylate (Phase II)	Serine protease inhibitor: blocks host TMPRSS2, preventing virus entry【69†L416-L424】.	Targets Coronaviridae (SARS-CoV-2) entry; also active vs influenza in vitro.	(drug host-targeted)	Phase II (COVID)	Approved for pancreatitis (JP); repurposing.	In vitro: inhibits SARS-CoV-2 entry in lung cells (IC₅₀ ~26 μM)【69†L416-L424】. Human COVID trials inconclusive (no clear benefit yet).	mg TID (influenza trial) or similar. Well tolerated.	Indirect broad potential (would affect any TMPRSS2-using virus) but requires TMPRSS2 expression. COVID trial negative to date (NCT04608208).	Hoffmann et al., Cell 2020 (not in refs).
NV-387 (NanoViricides) (Phase I)	“Nanoviricide”: cell-membrane-mimetic polymer that binds viral envelope and dismantles virus (multivalent).	Enveloped viruses: reported activity vs SARS-CoV-2 (beta-coronavirus), RSV (Paramyxoviridae), and orthopoxviruses (Vaccinia, monkeypox)【14†L4-L9】; in vitro in animal models.	(Coronaviridae, Paramyxoviridae, Poxviridae)	Phase I (completed)	Not approved (R&D).	Preclin: Animal data (company report) show survival in vaccinia model; RSV activity ~ribavirin levels【14†L4-L9】. Phase I: completed with no significant toxicity【14†L4-L9】. Plans for Phase II RSV.	Oral formulation (capsule) in trials. Good safety so far (no SAEs in Phase I).	Novel mechanism: low risk of resistance. Yet human efficacy unproven.	【14†L4-L9】; NCT05667557 (ongoing RSV trial).

Breadth Ranking and Metric

We ranked all agents by spectrum breadth (viral families count) to prioritize their true cross-virus coverage. For example, ribavirin scored ~15 (active against paramyxoviruses, arenaviruses, filoviruses, flaviviruses, coronaviruses, orthomyxoviruses, etc. as documented in extensive in vitro studies【60†L205-L213】【69†L323-L332】). Galidesivir scored ~9 families【18†L72-L79】, nitazoxanide ~7【39†L179-L188】, molnupiravir ~6【28†L327-L330】, favipiravir ~5【35†L363-L372】, and remdesivir ~4【31†L370-L375】【31†L379-L384】. These values are summarized in the “Spectrum Score” columns of Tables A/B. The combined ranked table below lists all agents (approved and in trials), sorted by breadth (highest to lowest). This ranking aligns with efficacy reports: e.g. ribavirin and galidesivir have the broadest in vitro spectra, whereas agents like camostat or SARS-specific protease inhibitors score low.

The chart below illustrates spectrum scores (number of virus families) for representative BSAs, highlighting ribavirin’s extremely broad activity compared to others:

Figure:** Spectrum breadth (families) of selected BSAs (higher = broader spectrum).

Rank	Agent	Families (%)	Representative Viruses	Phase	Status

	Ribavirin																RSV, Lassa, HCV, flu, Ebola, SARS, etc.【60†L205-L213】【69†L323-L332】	Approved	FDA, EMA
		Galidesivir										Ebola, Marburg, SARS, MERS, Dengue, Zika【18†L72-L79】	Phase I	BARDA
			Nitazoxanide								Influenza, RSV, SARS-CoV-2, rotavirus, HBV, HCV, dengue【39†L179-L188】	Phase III	(Repurposing)
				Molnupiravir							SARS-CoV-2, SARS, MERS, influenza, Ebola (in vivo)【28†L327-L330】	Approved	EUA
					Favipiravir						Influenza, SFTSV, SARS, Ebola (animal)【35†L369-L377】	Approved	JP, CN, RU
						Remdesivir					Ebola (NHP), SARS, MERS, RSV (models)【31†L370-L375】【69†L343-L352】	Approved	FDA, EMA
							Arbidol				Influenza, Zika, WNV【52†L277-L285】	Approved	CN, RU
								Triazavirin				Influenza, TBE (Flavi), RVF (Bunya)【49†L234-L242】	Approved	RU
									NV-387				SARS-CoV-2, RSV, Orthopox (preclin)【14†L4-L9】	Phase I	(nano-therapeutic)
										Brincidofovir				Smallpox, adenovirus, CMV (DNA viruses)【36†L1-L4】【69†L398-L406】	Approved	FDA (SGS)

(*Spectra of additional investigational agents omitted for brevity.*)

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