As readers know, I have long urged, following the science, that Covid is airborne, and that its main mode of transmission is via aerosols. (I was initially persuaded by an epidemiological study, now consigned to link rot, that showed a seat diagram on a Chinese bus with the index case and how many were infected. It seemed clear that neither fomites nor hacked up droplets could be the cause, since the seats were widely separated. Many more such studies followed. No such studies followed for fomites or droplets.) On April 30 — after enormous efforts from aerosol scientists — WHO changed its guidance to reflect that Covid is airborne. On May 7, CDC followed. So, after more than a year, we have finally agreed Covid’s mode of transmission. It is to be hoped that science-based mitigation measures — especially ventilation — follow.