Brittney Lofthouse – Contributing Writer
While health experts remain adamant that receiving a COVID19 vaccine is the best way to fight the spread of COVID19, Macon County Health Department Director Kathy McGaha said that once someone tests positive, treatment options are available locally. Some early evidence suggests that mAb (Monoclonal Antibody) treatment can reduce the amount of the SARS-CoV-2 virus (the virus that causes COVID-19) in a person’s system. This amount is known as viral load. Having a lower viral load means you may have milder symptoms thereby decreasing the likelihood of a stay in the hospital.
Last May, the U.S. Food and Drug Administration originally issued an emergency use authorization (EUA) for the monoclonal antibody therapy sotrovimab for the treatment of mild-to-moderate COVID-19 in adults and pediatric patients (12 years of age and older weighing at least about 88 pounds) with positive results of direct SARS-CoV-2 viral testing and those who are at high risk for progression to severe COVID-19, including hospitalization or death. Since then, the treatment has been utilized more frequently, especially as the cases of Delta Variant of COVID19 rapidly increased across the country. The FDA also has revised the original EUA to also allow the treatment to be used as post-exposure prophylaxis (prevention) for COVID-19 in adults and pediatric individuals.
While the treatment is not used for all patients who are hospitalized and already receiving oxygen, with monoclonal antibody therapy, physicians now have a way to help prevent severe symptoms from developing in those who are high risk.
The primary data supporting the EUA reissuance for post-exposure prophylaxis of COVID-19 are from a Phase 3 trial. The trial was a randomized, double-blind, placebo-controlled clinical trial studying a single dose of REGEN-COV for prevention of COVID-19 in household contacts of individuals infected with SARS-CoV-2. Cases were confirmed using real-time reverse transcription–polymerase chain reaction (RT-PCR), one of the most accurate laboratory methods for detecting, tracking, and studying COVID-19. An 81% reduction in confirmed symptomatic COVID-19 cases was observed with REGEN-COV compared to placebo at day 29 in cases who were RT-PCR negative and seronegative at baseline (the primary analysis population). In the overall trial population, a 62% reduction in RT-PCR confirmed symptomatic COVID-19 cases in the REGEN-COV group compared to placebo at day 29.
REGEN-COV consists of the monoclonal antibodies casirivimab and imdevimab, administered together. Monoclonal antibodies are laboratory-made proteins that mimic the immune system’s ability to fight off harmful pathogens, such as viruses like SARS-CoV-2.
The authorized dose for REGEN-COV for both treatment and as post-exposure prophylaxis is 600 mg of casirivimab and 600 mg of imdevimab administered together.
For treatment, intravenous infusion is strongly recommended; subcutaneous (under the skin) injection is authorized as an alternative route of administration when intravenous infusion is not feasible and would lead to delay in treatment.
For post-exposure prevention, either intravenous infusion or subcutaneous injection is appropriate. For individuals who remain at high risk of exposure to another individual with SARS-CoV-2 for longer than four weeks, and who are not expected to mount an adequate immune response to full SARS-CoV-2 vaccination, following an initial dose of 600 mg of casirivimab and 600 mg of imdevimab, repeat doses of 300 mg of casirivimab and 300 mg of imdevimab once every four weeks are appropriate for the duration of ongoing exposure.
At the beginning of September, Clay County Leadership announced that a Regeneron COVID-19 Monoclonal Antibody Treatment facility was scheduled to open and that county staff had been working for several weeks to make the facility a reality, utilizing existing space and resources, while partnering with state officials and departments to ensure adequate supplies and materials. The site opening was delayed but later opened at the end of September and is serving as a pilot program for the state.
While the antibody treatment is intended to reduce the severity of COVID19 once positive, hospitals working to treat hospitalized patients remain the priority thus hindering efforts to provide additional staffing for new operations.
McGaha said that the antibody treatment is a welcome option to treat patients after they become positive, however vaccines remain the best option at not only preventing exposure, but with controlling the spread of COVID19 to begin with, especially since the antibody treatment is limited as to whom it is available.