Denmark and Norway have become the latest European countries to recommend people aged over 65 should avoid the Oxford AstraZeneca vaccine.
Medical regulators in both countries said more evidence about the vaccine s effectiveness among older people is needed before it can be safely recommended to them.
Germany, France and Sweden have also discouraged people aged over 65 from taking the jab, while Switzerland has refused to approve it, saying new studies are needed.
It comes after a mighty row between the EU and AstraZeneca over the supply of jabs, and despite the fact that Oxford scientists who developed the vaccine and UK PM Boris Johnson have dismissed concerns about its safety.
Switzerland has refused to approve the AstraZeneca Covid, vaccine with regulators raising concerns over insufficient test data and arguing new studies are needed.
It comes after France, Sweden and Germany advised against administering the jab to those over 65 and Emmanuel Macron claimed it was almost ineffective for the age bracket.
That is despite Oxford data published this week suggesting the jab is 76 per cent effective after just one dose, and may also prevent 67 per cent of infection.
British Prime Minister Boris Johnson has also weighed in, saying the jab is is very good and efficacious in all age groups.
Continental objections to the jab come amid a furious row between the EU and AstraZeneca over lagging supply, which has seen newly-unshackled Brexit Britain storm ahead in its immunisation roll-out.
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Comparisons between Britain s well-oiled rollout and the bloc s own sluggish delivery has stoked frustrations
Brussels has pointed the finger at AstraZeneca and claims it it not meeting its contractual obligations
EU s woes date back months to protracted negotiations to initially procure vaccines and internal wrangling
Gripped by the pandemic, Brussels from the start resolved to collectivise its vaccine purchasing power