People under 30 have been told there may be a “small delay” to when they will receive a coronavirus vaccine, given adults in that age group are now being recommended to take an alternative jab to the one produced by AstraZeneca.
Jonathan Van-Tam, England’s deputy chief medical officer, said the rollout change was a “course correction” and a precaution against the “vanishingly rare” side-effect of blood clots.
It came after there were 79 reports of rare blood clots with low platelets – some, but not all of them, in the brain, in the UK up to 31 March. There were also 19 deaths, among more than 20m AstraZeneca jabs administered so far.
Van-Tam said it was “quite normal” and “business as usual” for experts to alter their preferences on how to treat patients, but acknowledged it could have a knock-on effect for when people get offered a jab, given that only the Pfizer vaccine is now being distributed across the UK, while the Moderna one began to be offered in Wales on Wednesday.
Speaking at a press conference alongside experts from the Medicines and Healthcare products Regulatory Authority (MHRA) and Joint Committee on Vaccines and Immunisation (JCVI), Van-Tam said: “There might be a small delay sometimes, there might be a slightly greater distance that some people might be asked to travel. But the NHS is all over this and understands the challenge of making the advice from JCVI truly operational in a smooth way.”
About 10 million people are likely to be affected by the change, with the ONS estimating there were 10,161,904 people in the UK aged 18 to 29 as of 2019. Under-30s who have already had the first dose of the AstraZeneca vaccine are being advised to still take the second dose of the same vaccine.
Van-Tam predicted the effect of delays to the overall vaccine rollout “should be zero or negligible” because of the supplies already ordered by the UK of alternative vaccines.
While a fourth vaccine from Johnson & Johnson has not yet been authorised by the MHRA, Van-Tam said it was “in the frame” of thinking about future supplies and added it had “always been part of the UK strategy, to have multiple horses in the race so that we would always be in a good position if we needed flexibility to be able to exercise it”.
Boris Johnson insisted there would be no major disruption to the rollout. The prime minister said: “I don’t see any reason at this stage at all to think we need to deviate from the roadmap and we’re also very secure about our supply.”
What are the most common side-effects from the Covid vaccines?
According to Public Health England, most side-effects from the Covid vaccines – Pfizer/BioNTech and Oxford/AstraZeneca – are mild and short-lived. These include soreness where the jab was given, feeling tired or achy and headaches. Uncommon side-effects include having swollen lymph nodes.
Why do the common side-effects occur?
“The sore arm can be either due to the trauma of the needle in the muscle, or local inflammation in the muscle probably because of the chemicals in the injection,” said Prof Robert Read, head of clinical and experimental sciences within medicine at the University of Southampton and director of the NIHR Southampton Biomedical Research Centre.
“The other common side-effects – the muscle aches, flu-like illness and fatigue – are probably due to generalised activation of the immune system caused by the vaccine. What this means is that the white blood cells that are stimulated by the vaccine to make antibodies themselves have to secrete chemicals called cytokines, interferons and chemokines, which function to send messages from cell to cell to become activated.”
Are blood clots a side-effect of the vaccines?
The Oxford/AstraZeneca jab has been linked to a small but concerning number of reports of blood clots combined with low platelet counts (platelets are cell fragments in our blood that help it to clot). Distribution of the Johnson & Johnson vaccine has been "paused" in the US while scientists investigate six incidences of a rare type of blood clot.
These include a rare clot in the brain called cerebral venous sinus thrombosis (CVST). In an unvaccinated population, upper estimates suggest there may be 15 to 16 cases per million people per year.
The Medicines and Healthcare products Regulatory Agency (MHRA) said recipients of the Oxford/AstraZeneca jab should look out for new headaches, blurred vision, confusion or seizures that occur four days or more after vaccination. The MHRA also flagged shortness of breath, chest pain, abdominal pain, leg swelling and unusual skin bruising as reasons to seek medical advice.
Up to and including 31 March, the MHRA said it received 79 reports of cases of blood clots combined with low platelets, including 19 deaths, following more than 20m doses of the Oxford/AstraZeneca jab. That equates to about four cases for every million vaccinated individuals.
Two cases of blood clots with a low platelet count have also been reported among recipients of the Pfizer/BioNTech jab. The European Medicines Agency is also examining three cases of venous thromboembolism blood clots involving the Johnson & Johnson jab.
The MHRA says blood clots combined with low platelets can occur naturally in unvaccinated people as well as in those who have caught Covid, and that while evidence of a link with the Oxford/AstraZeneca vaccine has become stronger, more research is needed.
Nicola Davis Science correspondent
The vaccines minister, Nadhim Zahawi, maintained the same position, promising: “We will follow the advice and are confident in meeting our programme targets.”
A government source said “people don’t need to worry” about not getting vaccinated before current targets.
They said the country was still on course for all over-50s to be offered their first injection by mid-April, and for that to expand to all adults by the end of July. “We’ve got enough supplies of all the vaccines coming on stream in the next few weeks and months, including 17m doses of Moderna,” they added.
Concerns about the UK’s supply of vaccines began rising a few days ago, when the number of jabs given dipped to its lowest point in months earlier this week – 96,000 shots on Sunday and just over 105,000 on Monday, the lowest figures since the government started publishing daily numbers in January.
The government had previously warned the rollout would slow in April, due to manufacturing issues of the AstraZeneca vaccine, including at a site in India.
