Phage therapy for secondary bacterial infections with COVID-19

With more than 200 million people affected and 4.5 million deaths so far, the coronavirus disease 2019 (COVID-19) pandemic has become one of the greatest disasters in human history. Secondary bacterial infections (SBIs) are a known complication of viral respiratory infections, and are significantly associated with poorer outcomes in COVID-19 patients despite antibiotic treatments. The increasing antimicrobial resistance (AMR) in bacteria and the decreasing options available in our antimicrobial armory worsen this crisis and call for alternative treatment options. As natural killers of bacteria, phages are recognized as promising alternatives to antibiotics in treating pulmonary bacterial infections, however, little is known about their use for treating SBIs during virus pandemics such as COVID-19. This review highlights the situation of SBIs in COVID-19 patients, and the distinct strengths and limitations of phage therapy for their containment.