The Fair Isle, with a population of just 48 people, received batches of the AstraZeneca vaccine this week after vials were flown to the island.
All of the adult population have now received both doses of the vaccine.
The island, which is three miles long and one-and-a-half miles wide, is home to an older community, and bringing people out to the mainland clinics for vaccination was not an easy option.
So it was decided by NHS Shetland that the vaccine would be transported to the island in a cool box via a plane.
John Best, the oldest islander, told the BBC that the island now feels like "one of the safest places in the country".
"It's a funny thing", he said, "because this was a very welcoming island. And it will be again.
"But it's an element we haven't had for about a year now."
Residents on the island only got reliable 24-hour electricity in 2018.
Electricity was powered by wind and two generators, with the costly diesel-run kit switched off overnight to save resources.
While some residents built back-up battery supplies for their homes and businesses - including the island’s shop in order to keep its freezers running - many were left powerless throughout the night.
But for the last three years, a round-the clock supply has been available thanks to a £3.5 million renewable electricity system.