NIH Updates Testing, Treatment Guidelines During Cocirculation of Influenza and COVID-19

INFLUENZA VACCINATION. No data exist on safety, immunogenicity, or effectiveness of influenza vaccines in patients with mild COVID-19 or those recovering from COVID-19; optimal timing for influenza vaccination in these patients is unknown. Based on practice following other acute respiratory infections, the Panel recommends that persons with COVID-19 should receive an inactivated influenza vaccine (BIII).

INFLUENZA VACCINATION. It is not known whether dexamethasone or other immunomodulatory COVID-19 therapies will affect the immune response to influenza vaccine. Despite uncertainty, as long as influenza viruses are circulating, an unvaccinated person with COVID-19 should receive the influenza vaccine after substantial improvement or recovery from COVID-19.

CLINICAL PRESENTATION OF INFLUENZA VS COVID-19. Signs and symptoms of uncomplicated, clinically mild influenza overlap with those of mild COVID-19. Ageusia and anosmia can occur with both diseases but are more common with COVID-19. Fever is not always present in patients with either disease, particularly among the immunosuppressed or elderly.

COMPLICATIONS OF INFLUENZA VS COVID-19. Complications of the 2 viruses can be similar, but onset of severe disease and complications in influenza typically occurs within 1 week of illness onset vs during the second week of illness for COVID-19. Coinfection with influenza A or B and SARS-CoV-2 has been described in case reports/series, but frequency, severity, and risk factors for coinfection with both viruses versus for infection with either one are unknown.

DIAGNOSIS OF INFLUENZA AND COVID-19. Only testing can distinguish between severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and influenza virus infections and identify coinfection with SARS-CoV-2 and influenza virus. The Panel recommends testing for both viruses in all hospitalized patients with acute respiratory illness.

DIAGNOSIS OF INFLUENZA AND COVID-19. The Panel recommends influenza testing in outpatients with acute respiratory illness if the results will change clinical management of the patient (BIII). Testing for other pathogens should be considered depending on clinical circumstances, especially in patients with influenza in whom bacterial superinfection is a well-recognized complication.

CODIAGNOSIS OF INFLUENZA AND COVID-19. Several FDA Emergency Use Authorizations (EUAs) have been granted for multiplex assays that detect SARS-CoV-2 and influenza A and B; results are available from within 15 minutes to 8 hours on a single respiratory specimen.

ANTIVIRAL TREATMENT OF INFLUENZA. The treatment of influenza is the same in all patients regardless of SARS-CoV-2 coinfection (AIII). The Panel recommends that hospitalized patients be started on empiric treatment for influenza with oseltamivir as soon as possible without waiting for influenza testing results (AII).

ANTIVIRAL TREATMENT OF INFLUENZA. Antiviral treatment of influenza can be stopped when influenza has been ruled out by nucleic acid detection assay in upper respiratory tract specimens for nonintubated patients and in both upper and lower respiratory tract specimens for intubated patients.