Botox top up after having covid. Is there much evidence that it could affect immunity?

I had Botox for the first time on my chin eyes, had tiny amounts to assess my tolerance and the effect. In the meantime I caught covid and my practitioner has advised I can’t have the top up as you have to wait at least two weeks after a negative lateral flow to have any Botox as the immune could go “haywire” I’m now missing out on the top up- expensive miss out. Is there much evidence for this? I’m aware of the vaccination and associations with heightened responses (I’ve had mine months ago)