The moment we all hoped we would never see is finally among us: the collision of coronavirus disease 2019 (COVID-19) and influenza (flu) season. Almost a year later, the novel coronavirus outbreak that started in December 2019 in Wuhan, China continues to circulate throughout the United States and worldwide. Despite new findings of the virus occurring on a regular basis, many unknowns remain, including how long it will circulate during the 2020-2021 influenza season.

The Centers for Disease Control and Prevention (CDC) provides direction on patients with suspected or confirmed COVID-19 in their 2020-21 Influenza Season Recommendations, which focuses on the use of vaccines for the prevention and control of seasonal flu.

“Because [severe acute respiratory syndrome coronavirus 2] is a novel coronavirus, clinical experience with influenza vaccination of persons with COVID-19 is limited. For those who have acute illness with suspected or laboratory-confirmed COVID-19, clinicians can consider delaying influenza vaccination until the patients are no longer acutely ill. If influenza vaccination is delayed, patients should be reminded to return for influenza vaccination once they have recovered from their acute illness.”1

Among the Frequently Asked Influenza (Flu) Questions: 2020-2021 Season, the CDC makes a supporting statement regarding administration of a flu vaccine for a patient with suspected or confirmed COVID-19.

 “Vaccination should be deferred (postponed) for people with suspected or confirmed COVID-19, regardless of whether they have symptoms, until they have met the criteria to discontinue their isolation. While mild illness is not a contraindication to flu vaccination, vaccination visits for these people should be postponed to avoid exposing health care personnel and other patients to the virus that causes COVID-19. When scheduling or confirming appointments for vaccination, patients should be instructed to notify the provider’s office or clinic in advance if they currently have or develop any symptoms of COVID-19.”2

If a patient in the community has not received a flu vaccination prior to a COVID-19 infection, it may be administered after home isolation is appropriately discontinued. For persons with COVID-19 who have symptoms, discontinuation is appropriate at least 10 days after symptom onset.  

Patients must also be at least 24 hours without fever or the use of fever-reducing medications, in addition to symptom improvement. The 10-day symptom onset is subjective and may be extended to 20 days for those with severe illness given the potential of replication-competent virus continuing to be produced beyond 10 days.3 When screening patients for flu vaccines in clinics, community pharmacies, and hospitals, it will now be imperative to assess COVID-19 history given limited clinical experience. 

As health care providers, it remains important to promote annual flu vaccines during the season. Given the collision of COVID-19 and flu season, receiving the flu vaccine may hold additional benefits by reducing symptoms that may be confused with those of COVID-19.

Moreover, promoting flu vaccines may lead to prevention and reduction in the severity of the flu illness, lessen the amount of flu-related hospital admissions, and protect our essential workers. Alleviating preventable stress on the current US health system in the midst of COVID-19 is vital.1

The CDC recommendation for an annual flu vaccine for all persons 6 months and older (who do not have any contradictions) remains in place.1 Essential workers, persons at increased risk for severe illness from COVID-19, and persons at increased risk for serious flu complications are groups who should especially receive their annual flu vaccine.2

Persons at increased risk for severe illness from COVID-19 include those aged 65 years and older, resident of nursing homes and long-term care facilities, and persons of all ages with certain underlying medical conditions.2 Underlying medical conditions include cancer; chronic kidney disease; chronic obstructive pulmonary disease; an immunocompromised state from solid organ transplant; obesity (body mass index [BMI] of 30 or greater), serious heart conditions such as heart failure; coronary artery disease or cardiomyopathies; sickle cell disease; and type 2 diabetes mellitus.4

Severe illness from COVID-19 has also been observed to disproportionally effect racial and ethnic minority groups due to disparities in the health system amongst poverty and health care access.2 Such barriers must be removed to allow equal treatment and fair opportunities to health care.5

Persons at increased risk for serious influenza complications are similar to the demographic of persons at increased risk for severe illness from COVID-19. Specific high-risk groups and conditions for flu include children aged 6 to 59 months; persons ≥50 years of age; adults and children with chronic pulmonary, cardiovascular, renal, hepatic, neurologic, hematologic, or metabolic disorders, including asthma and diabetes mellitus; persons who are immunocompromised, including but not limited to causes by medication or HIV/AIDS; pregnant women; persons aged 6 months to 18 years of age receiving aspirin or salicylates; residents of nursing homes or long-term care facilities; American Indians/Alaska natives; and persons with a BMI ≥40.1

The CDC provides guidance and resources for health care facilities, inpatient and outpatient settings, to help ensure safe delivery of flu vaccines during the COVID-19 pandemic.2

REFERENCES
  1. Grohskopf LA, Alyanak E, Broder KR, et al. Prevention and Control of Seasonal Influenza with Vaccines: Recommendations of the Advisory Committee on Immunization Practices — United States, 2020–21 Influenza Season. MMWR Recomm Rep. 2020;69(8):1–24. https://www.cdc.gov/mmwr/volumes/69/rr/rr6908ahtm?s_cid=rr6908a1_w. Accessed date October 4, 2020.
  2. Centers for Disease Control and Prevention. Frequently Asked Influenza (Flu) Questions: 2020-2021 Season. https://www.cdc.gov/flu/season/faq-flu-season-2020-2021.htm#Flu-and-COVID-19. Updated September 21, 2020. Accessed October 4, 2020.
  3. Centers for Disease Control and Prevention. Discontinuation of Isolation for Persons with COVID-19 Not in Healthcare Settings. https://www.cdc.gov/coronavirus/2019-ncov/hcp/disposition-in-home-patients.html. Updated July 20, 2020. Accessed October 4, 2020.
  4. Centers for Disease Control and Prevention. People with Certain Medical Conditions. https://www.cdc.gov/coronavirus/2019-ncov/need-extra-precautions/people-with-medical-conditions.html?CDC_AA_refVal=https%3A%2F%2Fwww.cdc.gov%2Fcoronavirus%2F2019-ncov%2Fneed-extra-precautions%2Fgroups-at-higher-risk.html. Updated September 11, 2020. Accessed October 4, 2020.
  5. Centers for Disease Control and Prevention. Health Equity Considerations and Racial and Ethnic Minority Groups. https://www.cdc.gov/coronavirus/2019-ncov/community/health-equity/race-ethnicity.html?CDC_AA_refVal=https%3A%2F%2Fwww.cdc.gov%2Fcoronavirus%2F2019-ncov%2Fneed-extra-precautions%2Fracial-ethnic-minorities.html. Updated July 24, 2020. Accessed October 4, 2020.