Journal of Antivirals & Antiretrovirals
Open Access

Broad-Spectrum Antiviral Agents in the Fight against Emerging Viruses

Camila Esteban^{* *}Correspondence: Camila Esteban, Department of Virology, Institute for Infectious Diseases, Barcelona Biomedical Research Center, Spain, Email:

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Description

The rise of emerging viral infections such as SARS-CoV-2, Zika, Ebola, and various influenza strains has underscored the global need for broad-spectrum antiviral agents (BSAAs) capable of targeting multiple virus families. Unlike traditional antivirals that are virus-specific, BSAAs act on conserved viral or host targets shared across different viruses, offering a promising strategy for pandemic preparedness. These agents can be vital in the early stages of outbreaks when specific diagnostics or targeted treatments are unavailable. BSAAs work by interfering with common viral life cycle steps such as entry, replication, assembly, or host immune modulation, enabling their use against a wide variety of pathogens. Several compounds, including remdesivir, favipiravir, and ribavirin, have shown activity against more than one virus family, supporting their role as potential first-line defenses. Moreover, repurposing of existing drugs, such as certain antimalarials and antibiotics with antiviral properties, offers a cost-effective and rapid strategy for addressing novel viral threats.

Host-directed BSAAs target cellular pathways essential for viral replication or host immune responses, thus reducing the chances of resistance development—a major limitation of conventional antivirals. Examples include cyclophilin inhibitors and modulators of the interferon response. By disrupting host-virus interactions or bolstering the immune system, these drugs create an inhospitable environment for a broad range of viruses. In addition, high-throughput screening techniques and artificial intelligence have accelerated the identification of candidate BSAAs by analyzing drug libraries for antiviral activity across various viral species. Drug repurposing campaigns during the COVID-19 pandemic further demonstrated the utility of such platforms, though with varied success, highlighting the complexity of host-pathogen interactions.

Despite their promise, BSAAs face several challenges. Chief among these is the balance between efficacy and toxicity, especially with host-directed therapies that may interfere with essential cellular functions. Ensuring that BSAAs do not impair normal host physiology while maintaining antiviral efficacy requires detailed mechanistic understanding and robust clinical trials. Furthermore, viral mutation rates and differences in viral protein structure can influence drug effectiveness, even among related virus families. Regulatory hurdles also remain, as the broad indications of these drugs necessitate expansive safety and efficacy assessments, especially when intended for use in emergent or unknown pathogens. Additionally, economic considerations often limit pharmaceutical investment in BSAAs due to uncertainties in demand and profitability compared to targeted antivirals or vaccines.

Global collaboration among research institutions, governments, and the pharmaceutical industry is essential for the successful development and stockpiling of BSAAs. Initiatives such as the WHO’s R&D Blueprint and CEPI (Coalition for Epidemic Preparedness Innovations) emphasize the prioritization of broad-spectrum therapeutics alongside vaccines in future pandemic preparedness strategies. Surveillance systems and virological databases also support this goal by providing critical insights into viral evolution, zoonotic spillover events, and drug susceptibility patterns. Importantly, equitable access to these treatments must be ensured across low- and middle-income countries, where emerging viruses often originate or are most devastating.

In conclusion, broad-spectrum antiviral agents represent a critical advancement in infectious disease management, particularly in the face of unpredictable viral outbreaks. Their ability to act across multiple virus families offers a strategic advantage in the global effort to curb viral epidemics and pandemics. However, achieving this potential will require overcoming scientific, regulatory, and economic barriers. A concerted international effort that includes investment in research, supportive policy frameworks, and public-private partnerships will be essential for translating laboratory discoveries into deployable antiviral solutions. With continued innovation and collaboration, BSAAs could become a cornerstone of our antiviral armamentarium and provide a more resilient defense against future viral threats.