Shetland’s health board is confident alternative vaccines will be available in time for the roll-out into the younger age groups.
NHS Shetland consultant in public health Susan Laidlaw said she expected to receive more supplies of Pfizer, following changes in guidelines for AstraZeneca.
Under-30s yet to receive their first jab will be offered alternative forms of the vaccine, after the UK drugs regulator this week found a possible link between AstraZeneca and rare blood clots.
The Medicines and Healthcare products Regulatory Authority said on Wednesday the risk was “extremely small” and the link had not yet been proven, though the evidence was “firming up”.
Following the new evidence, the UK government’s joint committee on vaccines and immunisation said healthy 18 to 29-year-olds at low risk of Covid should be offered a different jab.
For older people, however, the committee believed the benefits of the vaccine still far outweighed the risks.
Dr Laidlaw said the 18-29 age group had not yet been called for vaccination in Shetland.
“When they are we will have alternative vaccine available, which is most likely to be Pfizer as we know we are due to receive more supplies,” she said.
“In fact it may be that Pfizer will be the main vaccine that we have for the younger age groups anyway.”
Pfizer was the first vaccine available in the isles and used mainly for the top priority groups. AstraZeneca became the predominant form following the opening of mass vaccination centres in Lerwick.
The first doses of Moderna were also given in the UK this week, but Dr Laidlaw said previously that Shetland did not expect to receive that form of vaccine.
UK deputy chief medical officer Jonathan Van Tam said on Wednesday the change in advice around AstraZeneca would have “zero or negligible” effect on the timing of the programme.
Shetland is also reported to be on track with national targets.
Dr Laidlaw acknowledged last week, however, that national supply issues meant it may be June before every adult received their first dose, rather than May as first hoped.
Very few first doses were given in the past week, due to ongoing national supply issues and the wintry weather which saw the closure of vaccination centres on Tuesday.
In the seven days up until Wednesday, just 24 first doses were given, down from a peak last month when more than 600 were administered in a single day.
Over the same period 285 second doses were given, also fewer than past weeks.
Despite the slowing pace, 12,470 people had had received their first jab by Wednesday, the equivalent to two-thirds of the adult population.
Almost 3,000 people had also received their second jab – more than 15 per cent of the population.