Thread by @DrSimonAshworth

Reckless with Hydroxychloroquine, there is a better chance Trump will be right that REGN-CoV2 will be of benefit. But we don’t know for sure and RCTs are essential

Not so sure millions of doses will be available that fast though…

And there is some observational evidence in #COVID19 for convalescent plasma, the active ingredient of which is mixed antibody

ncbi.nlm.nih.gov/pmc/articles/P…

And convalescent plasma appears safe - adverse events occurred in 1% of people given convalescent plasma (extracted from those recovering from COVID)

pubmed.ncbi.nlm.nih.gov/32525844/

My experience? Having had COVID badly in April and developed antibodies, I had 2 recent heavy #COVID19 exposures. The worst when an ETT cuff ruptured and exhaled COV was blasting in my face. Patient was CoV2 PCR positive from the day before. I had PPE with FFP3, but still!

My other exposure came when my daughter developed COVID symptoms the day after we spent the day together for her birthday. Less dramatic but people are often at their most infectious at that stage.

I remain well.

But IV antibodies have limitations. They can make some viral diseases worse (Dengue) and with a half life of around 20 days, levels will be around 3% of peak after 10 weeks, so their effects don’t last long…

ncbi.nlm.nih.gov/pmc/articles/P…

And while convalescent plasma may well be beneficial, monoclonal antibodies run the risk of “viral escape” where viral mutations alter the sites the virus binds to and make it less effective

science.sciencemag.org/content/369/65…

For this reason REGN-Cov2 has a mixture of CoV2 antibodies, which are humanised murine antibodies

science.sciencemag.org/content/369/65…

Trump is likely wrong about vaccines - they will be the mainstay of our response to COVID if we are ever to return to “normal”, and vaccines are very cheap compared to antibodies…

But still recombinant immunoglobulins and plasma are promising therapies