> inoculated of buyer's remorse

Non native here. What's the meaning of inoculated here?

It's not the first time that I struggle to parse this word. In italian it keeps the original latin meaning and can be translated with "injected with". You could inoculate a vaccine but you could also inoculate a poison, so it does not carry the immunity meaning by default. English (US?) as far as I can tell use it as a synonym of "immune", is that so?