COVID-19 Update #114 for 12/15/2021

COVID-19 Antivirals
 
Pfizer announced that in the 28-day, 2,246 patient, Phase II/III, EPIC-HR trial (NCT04960202), where 0.7% of patients treated with the combination of nirmatrelvir and ritonavir were hospitalized with no deaths compared to 6.5% who were hospitalized or died with placebo in unvaccinated patients with mild-to-moderate COVID-19 at risk to progress to severe illness. After an interim analysis found an 89% reduction in COVID-19 related hospitalization or death, the FDA agreed with the Data Monitoring Committee, that the trial could be stopped in November 2021.
 
COVID-19 Vaccines
 
Pfizer and BioNTech announced that preliminary lab results found that antibody levels after a booster (third) dose of their COVID-19 vaccine neutralized the Omicron variant. There was a 25-fold reduction in neutralization in patients that received just two vaccine doses. This may not be enough to prevent infection but may protect against severe disease. South African scientists tested antibody neutralization with serum from 12 patient that had received the Pfizer-BioNTech COVID-19 vaccine. Half of the patients had recovered from COVID-19. There was a 41-fold decrease in neutralization, but previously infected patients have high neutralization. Therefore, patients that have received a booster (third) dose may maintain neutralization against Omicron. 
 
The FDA and CDC authorized a booster dose given six-months after their second dose of the Pfizer-BioNTech COVID-19 vaccine for 16 and 17 year-olds, on 12/9/2021.
 
COVID-19 Antibodies
 
The FDA approved an Emergency Use Authorization (EUA) for the combination of tixagevimab and cilgavimab (Evusheld, AstraZeneca) on 12/8/2021, for pre-exposure prophylaxis (prevention) of COVID-19 in patients 12 and older and weighting at least 40 kg with moderate to severe immune compromise due to a medical condition or immunosuppressive medications and who may not mount an adequate immune response to COVID-19 vaccination, currently have COVID-19 or if COVID-19 vaccination is not recommended. Tixagevimab and cilgavimab are administered as a one-time intramuscular dose. The FDA advised against using the drug in hospitalized patients, because a benefit has not been demonstrated. Healthcare providers should review the Fact Sheet for information on the authorized use of casirivimab and imdevimab and mandatory requirements of the EUA. Please see the FDA Letter of Authorization, Fact Sheet for Healthcare Providers, and Fact Sheet for Patients, Parents, and Caregivers. The U.S. government has purchased 700,000 doses that will be distributed at no charge.
 
In a 14-day, 941 patient, Phase III, CONTAIN COVID-19 trial (NCT04364737), treatment with convalescent plasma did not increase the number of patients that achieved clinical improvement compared to placebo in hospitalized COVID-19 patients.