Countries should continue to use the AstraZeneca Covid-19 vaccine, the World Health Organisation (WHO) said, saying there was no indication of a link between the jabs and blood clots.
It comes after Thailand said it will delay use of the AstraZeneca vaccine after several European countries temporarily suspended the jabs following a small number of reports of health problems.
Speaking via videoconference in Geneva, WHO director general Tedros Adhanom Ghebreyesus said: “As countries roll out Covid-19 vaccines, WHO is continuing to keep a close eye on their safety.
“WHO is aware that some countries have suspended the use of AstraZeneca vaccines based on reports of blood clots in some people who have received doses of the vaccine from two batches.
“This measure was taken as a precaution while a full investigation is finalised.
“It’s important to note that the European Medicines Agency has said there is no indication of a link between the vaccine and blood clots and that the vaccine can continue to be used while its investigation is ongoing.”
He said the findings and any change to the organisation’s recommendations following the investigation will be relayed to the public “immediately”.
His comments echoed earlier remarks made by WHO spokesperson Dr Margaret Harris, who described the vaccine as “excellent”.
Yong Poovorawan, an adviser to Thailand’s vaccination programme, said the delay, pending an investigation into the cause of reported side-effects, will not have a big impact on the rollout.
It came as AstraZeneca released a new statement saying there is no evidence of an increased risk of pulmonary embolism or deep vein thrombosis with the vaccine.
It said that, in fact, the occurrence is “significantly lower” in those who have been vaccinated than what would be expected among the general population.
The UK’s Medicines and Healthcare products Regulatory Agency (MHRA) has said there is no evidence to suggest the vaccine causes blood clot problems, and that people should still get their Covid-19 jab when asked to do so.
The European Medicines Agency (EMA) has also backed the jab’s safety and said there have been 30 reports of blood clots among close to five million people given the vaccine across Europe.
It said in a statement: “The position of EMA’s safety committee… is that the vaccine’s benefits continue to outweigh its risks and the vaccine can continue to be administered while investigation of cases of thromboembolic events is ongoing.”
On Thursday, Denmark, Norway and Iceland said they were temporarily halting all AstraZeneca vaccinations to investigate reports of blood clots among people who have had the jab.
Italy also followed Austria, Estonia, Latvia, Luxembourg and Lithuania in banning jabs from one particular batch of one million AstraZeneca vaccines, which was sent to 17 countries, after reports of a death.
AstraZeneca said in a statement on Friday: “An analysis of our safety data of more than 10 million records has shown no evidence of an increased risk of pulmonary embolism or deep vein thrombosis in any defined age group, gender, batch or in any particular country with Covid-19 vaccine AstraZeneca.
“In fact, the observed number of these types of events are significantly lower in those vaccinated than what would be expected among the general population.”
Earlier this week, the EMA reported that one person in Austria was diagnosed with blood clots and died 10 days after vaccination, but stressed there is “currently no indication that vaccination has caused these conditions”.
Another person was admitted to hospital with pulmonary embolism (blockage in arteries in the lungs) after being vaccinated.
Dr Phil Bryan, MHRA vaccines safety lead in the UK, said on Thursday: “Blood clots can occur naturally and are not uncommon.
“More than 11 million doses of the Covid-19 AstraZeneca vaccine have now been administered across the UK.
“Reports of blood clots received so far are not greater than the number that would have occurred naturally in the vaccinated population.”
Dr Bryan said the safety of the public always comes first and the issue is being kept under close review, “but available evidence does not confirm that the vaccine is the cause”.
Professor Anthony Harnden, deputy chairman of the Joint Committee on Vaccination and Immunisation, said: “Vaccine safety is critically important.
“Our UK regulator, the MHRA, reviews all reports of adverse events for both vaccines as they are reported.
“The public should have confidence that both vaccines used in the UK vaccination programme are safe and highly effective at preventing severe disease, including the prevention of blood clots caused by Covid.”