Moving too quickly to give people Covid booster jabs would deprive scientists of data on how well the vaccines work, AstraZeneca bosses have said.
“We do not yet know whether that third dose is clinically needed,” they say in the Telegraph.
It has already been announced that half a million of the most vulnerable in the UK will be offered a third dose.
But a separate booster programme, planned for September, has yet to be confirmed.
In their article, AstraZeneca chief-executive Pascal Soriot and biopharmaceuticals-research-and-development executive-vice-president Sir Mene Pangalos say giving the most vulnerable, who may not have built up a full immune response from the first two, a third, top-up dose is “sensible”.
But any decision to give a third, booster jab “to large swathes of the population”, to extend their protection from the first two, must be based on clinical data, which is only a few weeks away from being published.
That data, from a variety of sources, will show how protection from the vaccines is holding up six months on from the start of second doses being administered.
Meanwhile, another study will show how mixing vaccines might help.
“Moving too quickly to boost across the entire adult population will deprive us of these insights, leaving this important decision to rest on limited data,” Mr Soriot and Sir Mene write.
“We don’t know what mix of antibodies and T-cells are needed to prevent serious illness – the so-called correlates of protection.
“This is why we need the weight of the clinical evidence gathered from real-world use before we can make an informed decision on a third dose.”
And they are concerned about the “unnecessary burden on the NHS over the long winter months” of a booster rollout.
‘Ready to go’
One of the scientists who developed the Oxford-AstraZeneca vaccine has also criticised the plan for booster doses.
But former Health Secretary Jeremy Hunt has urged the government to begin a mass booster rollout, as Israel has, without waiting for a final decision from the Joint Committee on Vaccination and Immunisation (JCVI).
And the NHS across the UK has already been told to start planning to give Covid boosters alongside flu jabs to millions of over-50s ahead of the winter.
Meanwhile, the UK’s four chief medical officers are deciding whether 12- to 15-year-olds will be offered a Covid vaccine, after the JCVI said it would offer only a marginal health benefit.
Earlier this week, Vaccines Minister Nadhim Zahawi said jabs could be offered to adolescents within five days of a decision.
He also said a booster programme was “ready to go” as soon as data from studies was produced.