A Norwich-based expert on infectious diseases has backed the safety of a Covid vaccine - and said the decision by some European countries to pause rollout could cost lives.
Prof Paul Hunter said the Oxford/AstraZeneca vaccine "almost certainly" did not cause blood clots.
And the professor of medicine at the University of East Anglia said his advice to Boris Johnson would be to continue administering jabs.
Concerns have been raised in recent days after clots were identified in a handful of people who had received Oxford injections.
Several countries, including Germany, have suspended the product from their vaccination programmes, pending the results of an investigation by the European Medicines Agency (EMA).
But, while emphasising worries "cannot be ignored", Prof Hunter said the evidence was "pretty weak".
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"The issue has not been overblown but it is almost certain the AstraZeneca vaccine does not cause thrombosis," he said.
"There have been reports of thrombosis, but they have actually been less common than you might expect. Looking at the UK data, there is no really good evidence that either vaccine is associated with an increased risk.
"In Germany, there has been a suggested link to a type of thrombosis called CVT. They reported seven post-vaccine cases which is slightly higher than you might expect, but not dramatically so.
"The Germans have said 'we stopped not because we believe it, but because we have to investigate before our people have the vaccine'. A few countries did that and there was a snowball effect."
Regardless of the findings of the EMA's study, Prof Hunter believed so many countries pausing their rollouts had already done lasting damage.
He added: "Even if vaccines are causing CVT - and most people in the scientific community say it is probably not - the incidence is far lower than your risk of dying if if you don't have the vaccine.
"European countries have been cautious, but people who were nervous now won't have it. Ultimately this scare will lead to more cases, more people with severe disease and more deaths.
"If the prime minister had asked my opinion, I would have said carry on giving it out. I had the Oxford vaccine a few weeks ago, but this would not have changed my decision one iota."
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