Human Vaccines & Immunotherapeutics | 2021
Human Vaccines & Immunotherapeutics: news
Abstract
The U.S. Food and Drug Administration (FDA) has approved the monoclonal antibody bamlanivimab (LY-CoV555, Eli Lilly) for treatment of COVID-19 in subjects ≥12 years old at risk of progressing to severe disease or hospitalization. In a mid-stage clinical trial, bamlanivimab, whose sequence had been isolated from a patient after successful recovery, reduced the risk of an emergency-room visit to 3% compared to 10% in the placebo group. Countries around the world are entering into agreements with pharma and biotech companies to secure millions of doses of investigational SARS-CoV-2 vaccines, which are close to emergency-use regulatory approval in the U.S. only one year after the emergence of the virus. Two candidates proved to be >90% efficacious in trials involving tens of thousands of people. Two vaccines are based on mRNA delivery and in vivo expression of the antigen. The mRNA-1273 vaccine (Moderna) was shown to be 94% efficacious in preventing the disease according to interim results of Phase 3 data involving 30,000 subjects and 196 total infections. While the placebo group saw 30 severe cases, there were no severe cases in the experimental group. mRNA-1273 remains stable for a month at 4°C, which is important for delivery to remote areas with insufficient infrastructure. Another mRNA vaccine, BNT162b1 (Pfizer & BioNTech), reported 95% efficacy, including in the elderly. The placebocontrolled Phase 3 trial has enrolled 43,000 volunteers, and there were 162 cases in the final analysis. The vaccine needs to be stored at -70°C until the time of delivery; the company is working on a pulverized formulation as a follow-on. A non-replicating ChAdOx1-S vaccine (AstraZeneca) was 62-90% effective according to preliminary results of a Phase 3 trial with 10,000 individuals. Interestingly, the highest protection rate of 90% was reported for a cohort that received a lower first dose and full second dose, compared to 62% for two full doses. It remains to be determined whether the observation has medical significance. While there is a great public health need for rapid deployment of COVID-19 vaccines globally, scientists worry that too rapid a deployment might compromise ongoing clinical trials and the determining of long-term vaccine-associated effects, because of demands to transfer subjects from placebo to the experimental group. Two personalized cancer vaccines progress through clinical trials