Massive logistical exercise to deliver scheme

Health officials are gearing up for the biggest vaccination programme ever delivered in Scotland with the added complexity of trying to keep their plans Covid safe.

The Pfizer candidate vaccine, which has a 90% effectiveness rate, is expected to be the first available in Scotland but some of its properties, coupled with the pressure to churn out the jabs quickly, only add to the difficulty.

The Pfizer vaccine comes in a box with 195 multi-dose vials – around 975 doses – and lasts for around six months when stored at -75C.

At normal fridge temperature that window reduces to just five days, and at room temperature, ready for vaccination, there is around a two-hour expiry time.

The puzzle of how to make that work in rural and remote areas will be key.

Around 320 ,000 doses will arrive in Scotland by the end of December but scientists are still unsure how many people need to be vaccinated before things can return to normal.

Both the Pfizer and Modern a vaccines require two doses 28 days apart – something the health service will need to track.

The vaccination programme may also need to be repeated, possibly several times.

People in younger age groups without any pre existing health conditions will likely need to wait until late spring or early summer to be vaccinated, but that depends on when large quantities can be made available by the manufacturers.

Children will not be receiving either of the vaccines for now because clinical trials on people under the age of 18 have only just started.