“Mabs” for COVID-19: Patient Assessment

Please see the HHS September 9, 2021 release about expanding pharmacist-provided access to COVID-19 therapeutics

(Updated September 20, 2021)

Monoclonal antibodies or “mabs” are authorized in certain patients with a high-risk condition to treat mild to moderate COVID-19. Casirivimab/imdevimab and bamlanivimab/etesevimab are also authorized in certain patients as SARS-CoV-2 post-exposure prophylaxis.  Use of a “mab” may prevent COVID-19 or progression to severe COVID-19 and/or hospitalization when given early in the infection.  Use this algorithm to identify appropriate patients for potential use.

To qualify for a “mab” patients MUST be at least 12 years old AND weigh at least 88 pounds (40 kg).2,3,5

Treatment (initial assessment after meeting age and weight criteria):2,3,5

  1. Does the patient have a documented positive VIRAL test for COVID-19?
    • If YES, continue to the next question.
    • □ If no, the patient does not qualify for a COVID-19 monoclonal antibody.
  2. Does the patient have mild or moderate COVID-19 symptoms that started no more than 10 days ago?
    • If YES, continue to the next question.
    • □ If no, the patient does not qualify for a COVID-19 monoclonal antibody.
  3. Does the patient require supplemental oxygen for COVID-19 (or more than baseline due to COVID-19 symptoms)?
    • If NO, continue to the next question.
    • □ If yes, the patient does not qualify for a COVID-19 monoclonal antibody.
  4. Does the patient require hospitalization, based on severity of COVID-19 symptoms?
    • If NO, continue to the next section to see if the patient has a qualifying high-risk condition.
    • □ If yes, the patient does not qualify for a COVID-19 monoclonal antibody.

Treatment: Does the patient have at least ONE high-risk condition?2,3,5 (If YES, patient qualifies.) (Note:  other factors and conditions may increase a patient’s risk of severe COVID-19.  See https://www.cdc.gov/coronavirus/2019-ncov/need-extra-precautions/people-with-medical-conditions.html for more information.)

  • For all patients who qualify based on the initial assessment above:
    • □ older age (e.g., ≥65 years old)
    • □ obesity or being overweight defined as body mass index (BMI):
      • >25 kg/m2 (adults)
      • ≥85th percentile for age and gender based on CDC growth chart (adolescents)
    • □ cardiovascular disease (including congenital heart disease)
    • □ chronic kidney disease (CKD)
    • □ chronic lung disease (e.g., COPD, moderate-to-severe asthma, cystic fibrosis, interstitial lung disease, pulmonary hypertension)
    • diabetes (type 1 or type 2)
    • □hypertension
    • □immunosuppressive disease or immunosuppressive treatment
    • □medical-related technologic dependence (e.g., tracheostomy, gastrostomy, positive pressure ventilation [not related to COVID-19])
    • □conditions involving metabolic complexity (e.g., genetic or metabolic syndromes and severe congenital abnormalities)
    • □ neurodevelopment disorders (e.g., cerebral palsy)
    • □ pregnancy
    • □ sickle cell disease
    • □ other conditions/factors making the patient high risk for severe COVID-19 (e.g., race, ethnicity)

Post-exposure prophylaxis (initial assessment after meeting age and weight criteria) for patients at high risk of severe COVID-19 (see list above):3

  1. Is the patient considered NOT fully vaccinated (includes those less than two weeks after the second dose in a two-dose series or after one dose for a single-dose vaccine) or NOT expected to mount an adequate immune response to the vaccine?
    • If YES, continue to the next question.
    • If no, the patient does not qualify for post-exposure prophylaxis.
  2. Has the patient been in close contact with or exposed (based on CDC criteria) to someone infected with SARS-CoV-2 OR is that patient at high risk of exposure due to COVID-19 infection within their institutional setting (e.g., nursing home, prison)?
    • If YES, the patient qualifies for post-exposure prophylaxis.
    • If no, the patient does NOT qualify for post-exposure prophylaxis.

What monoclonal antibody dose should be used?

  • For treatment of mild to moderate COVID-19, monoclonal antibodies are one-time doses.2,3,5
    • □ bamlanivimab/etesevimab:2 700 mg/1,400 mg IV infusion
    • □ casirivimab/imdevimab:3 600 mg/600 mg IV infusion (Alternatively, can be given by subcutaneous injection when IV administration is not possible or to avoid treatment delays.3)
    • □ sotrovimab:5 500 mg IV infusion
  • For post-exposure prophylaxis:
    • casirivimab/imdevimab can be given as follows:
      • Initial dose:3  600 mg/600 mg by IV infusion or subcutaneous injection.
      • For ongoing exposure lasting four weeks or longer after the initial dose, additional dose(s) of casirivimab/imdevimab 300 mg/300 mg should be given by IV infusion or subcutaneous injection every four weeks for the duration of exposure.3
    • bamlanivimab/etesevimab:2 700 mg/1,400 mg IV infusion.
  • For details about administration or other information, refer to the specific emergency use authorization (EUA) document for each product. EUAs can be found at: https://www.fda.gov/emergency-preparedness-and-response/mcm-legal-regulatory-and-policy-framework/emergency-use-authorization#coviddrugs.

Help patients make an informed decision about receiving “mab” treatment or post-exposure prophylaxis.

  • Explain the possible benefit (reducing the risk of progression to a severe COVID-19 infection) and risks associated with monoclonal antibody treatment.
    • Allergic reactions (e.g., fever, chills, shortness of breath, wheezing) are rare.1  However, explain to patients that they will need to be observed for about one hour after completing the monoclonal antibody administration to monitor for a possible reaction.2-5
  • Make sure patients understand that treatment with a monoclonal antibody does not cure COVID-19.1
    • Advise patients they will need to continue to use infection control measures and isolate according to current health department guidance.1-3,5
  • There are not enough data available to assess possible risks associated with use of monoclonal antibodies in pregnant or lactating mothers.  Discuss with patients individually.  Only use monoclonal antibodies when the potential benefit (reduced disease severity) outweighs the risks (unknown).1-3,5

Where can patients receive monoclonal antibody therapy for COVID-19?


  1. American Pharmacists Association. Pharmacists’ referrals for monoclonal antibody treatment: assessing patients for potential COVID-19 treatment with monoclonal antibodies. February 25, 2021. https://aphanet.pharmacist.com/sites/default/files/audience/APhACOVID-19MAB0221_web.pdf. (Accessed May 27, 2021).
  2. FDA. Fact sheet for health care providers: emergency use authorization (EUA) of bamlanivimab and etesevimab. Revised September 2021. https://www.fda.gov/media/145802/download. (Accessed September 20, 2021).
  3. FDA. Fact sheet for health care providers: emergency use authorization (EUA) of REGEN-COV (casirivimab and imdevimab).  September 2021. https://www.fda.gov/media/145611/download. (Accessed September 20, 2021).
  4. HHS ASPR TRACIE. Planning considerations for monoclonal antibody administration. Updated September 1, 2021. https://files.asprtracie.hhs.gov/documents/aspr-tracie-covid-19-monoclonal-antibody-therapy-tip-sheet.pdf. (Accessed September 20, 2021).
  5. FDA. Fact sheet for healthcare providers emergency use authorization (EUA) of sotrovimab. May 2021. https://www.fda.gov/media/149534/download. (Accessed May 27, 2021).

Cite this document as follows: Clinical Resource,“Mabs” for COVID-19: Patient Assessment. Pharmacist’s Letter/Prescriber’s Letter. April 2021. [370402]

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