The Food and Drug Administration (FDA), in coordination with the Assistant Secretary for Preparedness and Response (ASPR), will allow distribution of bamlanivimab and etesevimab to resume in selected states, territories, and U.S. jurisdictions for the treatment of mild to moderate COVID-19 and post-exposure prophylaxis of COVID-19 in certain patients based on the combined prevalence of variants resistant to bamlanivimab and etesevimab. Bamlanivimab and etesevimab are not authorized for use in states, territories, and U.S. jurisdictions in which the combined frequency of variants resistant to bamlanivimab and etesevimab exceeds 5%, as determined by FDA. A list of states, territories, and U.S. jurisdictions in which bamlanivimab and etesevimab are and are not currently authorized is available here.
Frequently Asked Questions
No information is available regarding the safety or effectiveness of administering bamlanivimab and etesevimab after the first dose or completed series of a SARS-CoV-2 vaccine.
The CDC recommends that for partially and fully vaccinated patients who subsequently test positive for COVID-19, prior receipt of a SARS-CoV-2 mRNA vaccine should not influence COVID-19 treatment decisions or the timing of such treatments.1
To date, there is no data available from BLAZE-1 regarding the efficacy and safety of administration of a SARS-CoV-2 vaccine after receipt of bamlanivimab and etesevimab for the treatment of mild to moderate COVID-19.
Based on the estimated half-life of such therapies and evidence suggesting that reinfection is uncommon within the 90 days after initial infection, vaccination should be deferred for at least 90 days after receiving monoclonal antibodies. This is a precautionary measure until additional information becomes available, to avoid potential interference of the antibody therapy with vaccine-induced immune responses. This recommendation applies to people who receive passive antibody therapy before receiving any vaccine dose and between doses. Receipt of passive antibody therapy in the past 90 days is not a contraindication to receipt of COVID-19 vaccine. COVID-19 vaccine doses received within 90 days after receipt of passive antibody therapy do not need to be repeated.1
Bamlanivimab is a recombinant neutralizing human IgG1κ monoclonal antibody (mAb) to the spike protein of SARS-CoV-2, and is unmodified in the Fc region. Bamlanivimab binds to spike protein with a dissociation constant KD = 0.071 nM and blocks spike protein attachment to the human ACE2 receptor with an IC50 value of 0.17nM (0.025 µg/mL).
Etesevimab is a recombinant neutralizing human IgG1κ mAb to the spike protein of SARS-CoV-2, with amino acid substitutions in the Fc region (L234A, L235A) to reduce effector function. Etesevimab binds the spike protein with a dissociation constant KD = 6.45 nM and blocks spike protein attachment to the human ACE2 receptor with an IC50 value of 0.32 nM (0.046 µg/mL).
Bamlanivimab and etesevimab bind to different but overlapping epitopes in the receptor binding domain (RBD) of the spike protein. Using both antibodies together is expected to reduce the risk of viral resistance.
While there are some similarities, here’s how they are different:
- Monoclonal antibodies, like bamlanivimab and etesevimab, are designed to help provide passive immunity by giving the body antibodies to protect itself. Vaccines provide active immunity by helping the body make its own antibodies to protect itself.
- Monoclonal antibody drugs are designed to start working faster than vaccines, while protection provided by vaccines will generally last longer.
- Generally, scientists are able to develop antibody treatments faster than they are able to develop vaccines.
For information on Eli Lilly and Company's COVID-19 clinical trials, please click here.
- Patients interested in participating in one of our clinical trials for a potential COVID-19 treatment should visit Lilly TrialGuide for information regarding eligibility for ongoing trials.