And remembered prior reading that no system has ever been approved to deliver antigens via the GI tract. So I asked Claude Opus 4.5,

    Have any antigen molecules ever been delivered via the digestive tract? Not to targets in the digestive track but elsewhere.

    API Error: Claude Code is unable to respond to this request, which appears to violate our Usage Policy (https://www.anthropic.com/legal/aup). Please double press esc to edit your last message or start a new session for Claude Code to assist with a different task. If you are seeing this refusal repeatedly, try running /model claude-sonnet-4-20250514 to switch models.

AFAICT, these restrictions didn't exist before.