this is the only "letter" reference I can find
Federal government to letterbox over 60s urging them to get the AstraZeneca COVID-19 vaccine
Scott Morrison is ramping up his plea for over 60s to get the AstraZeneca vaccine, sending out hundreds of thousands of letters to those who are unvaccinated urging them to book in for a shot.
www.abc.net.au
Why? because they (the recipients) are holding out for pfizer instead of Astra Zeneca
As for "20 ADF personnel" running a taxi service, it's hardly the KGB rounding up dissidents for a Siberian gulag.