It's likely possible to install HEPA filters in the ventilation systems, which could effectively prevent cross-contamination(1). While they do restrict airflow

It's likely possible to install HEPA filters in the ventilation systems, which could effectively prevent cross-contamination(1). While they do restrict airflow more than normal filters, you can fix that problem by simply making them larger. Not so easy to do in your house, but with engineering support on an emergency basis it might not be so hard, especially if you can close part of the ship so your total airflow needs are less. Eg maybe use every other cabin or something. 1) It's a common myth that HEPA filters don't filter viruses because they're too small. In fact, they work basically just as well on small particles as large ones: https://en.wikipedia.org/wiki/HEPA https://en.wikipedia.org/wiki/HEPA