Scotland’s top doctor said Covid-19 vaccinations may be a staple “in the coming years”, although he could not say who may need to receive booster jabs.
More than 1.6 million Scots have received the first dose of the vaccine.
The Scottish Government hopes to offer it to all adults by the end of July.
But the chief medical officer has said vaccinations against coronavirus will likely not stop for good come the summer.
At the coronavirus briefing in Edinburgh, Dr Gregor Smith said: “What we don’t have yet is a full assessment as to how long that vaccination will confer immunity and, once we know that, we’ll know exactly when booster doses may or may not be required.”
New, more transmissible, variants of the virus, on which the effects of the vaccine are not fully understood, add a layer of complexity to the issue of ongoing vaccination, according to Dr Smith.
“The additional element that’s now started to come in, very strongly, to the mix, is about what are the impacts of these new variants of concern we’re beginning to see,” he said.
“Some of those have features in them that may mean it’s more likely that the virus can begin to show what we call immune escape, either away from natural immunity, or from the vaccine immunity that we give from the vaccination programme,” he added.
“I think it’s reasonable to suspect there will be an ongoing need for some sort of vaccination programme in some form over the coming years.
“But what we don’t know at this stage with confidence is what would be the interval between receiving your primary course and any subsequent booster course, because that’s very much dependent on how quickly other variants become apparent and established.
“I suspect that vaccination against the Sars Cov-2 virus is something that we’re going to be contemplating from this point in, particularly if we continue to follow a programme where we suppress the virus to as low a level as possible, not just in this country, but globally.”
If the countries of the world attempt to stamp out Covid-19, that means they will be dealing with localised outbreaks, as opposed to seasonal rises such as with flu.
Health Secretary Jeane Freeman, also addressing the briefing, said it was not yet clear who would need to be given another course of the vaccine.
However, she said planning was under way to understand how many people would need to be jabbed again.
She said: “The planning is under way to indicate the scenarios underneath that reasonable expectation of a repeat of the current scale of the vaccination programme – 4.45 million adults in Scotland – at one end, to the possibility that it may be a small number at the other end.
“It depends on all that evidence and information and knowledge that will come through people like Gregor to me and to us,” the health secretary added.