They were able to use plausible deniability by claiming it would stay in the lymph nodes. But you are correct that the lymph nodes are connected to the rest of the bodily fluids and not "isolated".
It's like saying when someone farts, it doesn't go in the atmosphere; it stays in a 2"x2" box in the air and you will have time to get a plastic bag, capture it and throw it in the garbage.
They were able to use plausible deniability by claiming it would stay in the lymph nodes. But you are correct that the lymph nodes are connected to the rest of the bodily fluids and not "isolated".
Yes, it would stand to reason the lymph system would be the last place you would want it.
It's like saying when someone farts, it doesn't go in the atmosphere; it stays in a 2"x2" box in the air and you will have time to get a plastic bag, capture it and throw it in the garbage.