On Wednesday, the government’s joint committee on vaccines and immunisation (JCVI) announced its recommendation that under-30s should be offered an alternative to the Oxford-AstraZeneca vaccine.

Amid heightened confusion, Full Fact has broken down some of the key facts behind the announcements:

• In the period up until 31 March, 20.2 million doses of the AstraZeneca vaccine had been administered in the UK
• The UK’s drugs regulator found that 79 have suffered this specific type of blood clot
• The Medicines and Healthcare products Regulatory Agency (MHRA) says this was equivalent to an overall risk of 1 in 250,000

To put this into context, we can compare this risk to the risks of becoming ill with Covid.

The Winton Centre for Risk and Evidence Communication at Cambridge University has calculated the potential harms of getting this type of blood clot after the vaccine, compared with the benefits of being vaccinated.

It found that the immediate potential for harm of the vaccine for those aged 20-29 slightly outweighs the benefits.

Vaccinating 100,000 people of that age will avoid about 0.8 intensive care admissions due to Covid-19 in a 16-week period.

However, for the same age group, the Winton Centre estimated that about 1.1 in 100,000 would suffer blood clots. But both risks are extremely small.

It’s right and reasonable that people have questions about the safety of the Oxford-AstraZeneca vaccine. The evidence suggests the associated risks are small.

But it is important that people have access to the available evidence—and that this information is put into context—so that they can make informed decisions.