[Lewis Thomson (OP)]

James would like help understanding the reasoning behind this situation.

"I've had covid and monoclonal antibodies treatment sotrovimab (Xevudy). Also 3 covid jabs. Also due covid booster.  CDC state Passive antibody product used for COVID-19 treatment: Defer COVID-19 vaccination for 90 days. What is there reasoning?"

Can you help him? Discuss in the comments below...

[Origin]

"I've had covid and monoclonal antibodies treatment sotrovimab (Xevudy). Also 3 covid jabs. Also due covid booster.  CDC state Passive antibody product used for COVID-19 treatment: Defer COVID-19 vaccination for 90 days. What is there reasoning?"

Ask your doctor, don't go online asking unknown people for medical advice!

[evan_au]

It sounds like you have gone several rounds with COVID!

Antibodies typically have a half-life of about 2 weeks. If your body is not exposed to a pathogen, production of the antibodies declines, and they are flushed out of your system.
- If you have had a COVID infection and a normal immune response, your body will be churning out antibodies to COVID at a high rate. This is why a recent COVID infection is regarded as being as good as vaccination, for a few months.
- Artificial antibodies are injected, so your body does not know how to make them. This means that they will be flushed out with a half-life of 2 weeks, and not replenished by your body. So protection is significantly reduced after 1 month.
- But I heard that some researchers were trying to modify their artificial antibodies so they lasted longer in the body (Sotrovimab is one of these) - maybe 3 months protection is possible?

Note that antibodies against one strain does not necessarily provide much protection against very different strains.
- For example, Omicron had many mutations, so those infected with earlier strains of COVID could be infected again with Omicron.
- The currently-approved vaccines, and artificial antibodies were developed against these early strains, so after a 3rd COVID vaccination, your best protection against Omicron is masks and social distancing.
See: https://en.wikipedia.org/wiki/Sotrovimab

[set fair]

The vaccine needs to induce an immune response. The monoclonal antibodies can do the job, or part of the job of the immune system and this will dampen the immune response from the vaccine. Specifically you may not produce the antibodies in the monclonal antibody cocktail, which have been selected because they are particularly potent.