Health impact and cost of COVID-19 prophylaxis with monoclonal antibodies

Background: The COVID-19 pandemic has led to over 600,000 deaths in the United States and continues to disrupt lives even as effective vaccines are available. We aimed to estimate the impact and health system cost of implementing post-exposure prophylaxis against household exposure to COVID-19 with monoclonal antibodies. Methods: We developed a decision-analytical model analysis of results from a recent randomized controlled trial with complementary data on household demographic structure, vaccine coverage, and COVID-19 confirmed case counts for the representative month of May, 2021. The model population includes individuals of all ages in the United States by sex and race/ethnicity. Results: In a month of similar intensity to May, 2021, in the USA, a monoclonal antibody post-exposure prophylaxis program reaching 50% of exposed unvaccinated household members aged 50+, would avert 1,813 (1,171 - 2,456) symptomatic infections, 526 (343 - 716) hospitalizations, and 83 (56 - 116) deaths. Assuming the unit cost of administering the intervention was US$ 1,264, this program would save the health system US$ 3,055,202 (-14,034,632 - 18,787,692). Conclusions: Currently in the United States, health system and public health actors have an opportunity to improve health and reduce costs through COVID-19 post-exposure prophylaxis with monoclonal antibodies.