"With the first readouts of trials of antibodies against COVID-19 appearing and others coming thick and fast, Nature Biotechnology asked a group of experts [including Professor Tillman Gerngross] to comment on the challenges and timelines for these products."

... "SARS-CoV-2 is less genetically diverse than most other RNA viruses, which may translate into a reduced ability to escape from neutralizing antibodies, especially broadly neutralizing antibodies that target conserved residues important for viral fitness," said Gerngross.

... "The programs from both Lilly and Regeneron have demonstrated exceptional safety, even at very high doses. In the absence of real efficacy data for vaccines, safety is going to be a big driver, and antibodies have so far passed that test with flying colors. I am also excited about the demonstrated impact on viral loads and hospitalization rates, although more work will have to be done to fully understand the benefit. Of all drug classes, [monoclonal antibodies or] mAbs have clearly demonstrated to be the most efficacious to date," said Gerngross.

... "A potent mAb with half-life extension enabling safe and reliable protection for up 12 months could be used as a vaccine alternative for individuals who respond poorly to, are not eligible for, or are simply unwilling undergo vaccination. Antibodies could also be used as additional protection for individuals at particularly high risk of developing complications of COVID-19, such as the elderly and individuals with certain comorbidities. Finally, unlike vaccines, mAbs have potential utility in outbreak and postexposure prophylaxis settings, with the ease of intramuscular or subcutaneous administration likely preferred in these circumstances. Based on the broad potential uses of mAbs in prophylaxis, phase 3 trials should ideally include individuals at high risk of exposure to SARS-CoV-2, either due to a documented known exposure or ongoing risk based on occupation or housing situation, as well as individuals at high risk of complications of COVID-19 should they develop SARS-CoV-2 infection," said Gerngross.