SARS-CoV-2 and Influenza Co-Infection: Fair Competition or Sinister Combination?

Area of Science:

• Respiratory viral infections
• Immunology
• Public Health

Background:

• COVID-19 remains a global health crisis, with increased severity observed during influenza seasons.
• Influenza and SARS-CoV-2 share transmission routes and target the respiratory tract, suggesting potential interactions.
• The precise mechanisms and clinical impact of influenza coinfection in COVID-19 patients are not fully understood.

Purpose of the Study:

• To review the factors influencing the interaction between influenza and SARS-CoV-2.
• To elucidate the potential impact of influenza coinfection on COVID-19 disease outcomes.
• To explore viral and host determinants of pathogen survival and synergism in the respiratory tract.

Main Methods:

• Literature review of studies on influenza and SARS-CoV-2 coinfections.
• Analysis of viral and host factors affecting pathogen interaction.
• Synthesis of current evidence on clinical outcomes of coinfected patients.

Main Results:

• Both viruses utilize similar replication strategies in the human respiratory system.
• Coinfection may lead to synergistic or antagonistic interactions between influenza and SARS-CoV-2.
• Existing clinical data on coinfection outcomes are inconclusive regarding mechanistic insights.

Conclusions:

• Understanding the interplay between influenza and SARS-CoV-2 is crucial for public health.
• Viral and host factors significantly influence the dynamics of coinfection in the lung microenvironment.
• Further research is needed to clarify the mechanistic basis of how influenza coinfection modifies COVID-19 severity.