ITV News Science Editor Tom Clarke explains how the AstraZeneca announcement is more about the "decrease in Covid overall rather than the risk of the vaccine"
All under-40s are to be offered an alternative to the Oxford/AstraZeneca Covid vaccine in a precautionary move after evidence of an "extremely small risk" of people suffering from blood clots after having the jab.
The Joint Committee on Vaccination and Immunisation (JCVI) advised that another vaccine should be offered to under-40s without underlying health conditions where an alternative is available, as long as it does not cause any substantial delays to the vaccination programme.
Why under-40s in the UK won't be offered the AstraZeneca vaccine
While the balance of benefit and risk for the AstraZeneca vaccine is very favourable for older people, it is more finely balanced for younger groups, who do not tend to suffer serious coronavirus illness.
Urging people to accept vaccines, the JCVI warned that reductions in uptake or speed of jab deployment will increase the size of any third wave of infection in the UK.
For this reason, it believes any vaccine would be better than no vaccine, even for those under the age of 40.
Watch ITV News Science Editor Tom Clarke's analysis:
Professor Wei Shen Lim, Covid-19 chairman for JCVI, said: "Safety remains our number one priority.
"We have continued to assess the benefit/risk balance of Covid-19 vaccines in light of UK infection rates and the latest information from the MHRA on the extremely rare event of blood clots and low platelet counts following vaccination.
"As Covid-19 rates continue to come under control, we are advising that adults aged 18 to 39 years with no underlying health conditions are offered an alternative to the Oxford/AstraZeneca vaccine, if available and if it does not cause delays in having the vaccine.
"The advice is specific to circumstances in the UK at this time and maximises use of the wide portfolio of vaccines available.
"The Covid-19 vaccines have already saved thousands of lives and the benefit for the majority of the population is clear – if you are offered the vaccine, you should take it."
Asked by ITV News Science Editor Tom Clarke whether there was concern this news could undermine confidence in the vaccine, Professor Lim said: "The purpose of the advice is to improve vaccine confidence if anything because the advice puts a high priority on safety.
"And we're trying to demonstrate that we are rigorously assessing the situation and where appropriate we will advise accordingly for the benefit of individuals and the public.
"So we hope that the advice will if anything serve to boost confidence and allow people who are being called up for vaccination now... to feel able to step up, accept the vaccine and be vaccinated."
Responding to the question, Professor Jonathan Van-Tam, deputy chief medical officer for England, said: "All of the opinion polls I read very clearly show that the British public has very, very high confidence in the vaccine programme in the UK, can already see what it is doing in terms of changing our future, and the data get better and stronger in terms of the layers of protection, not just the aversion of deaths, serious infections, but now the prevention of transmission on top for young adults."
Professor Van-Tam said continuing the vaccine programme and maintaining confidence was “critically important”, adding: "We don’t retain control of this disease unless we continue the rollout of the vaccination programme.”
He said that the vaccine programme is still "on target" to offer a first dose to all adults by the end of July.
"Sadly, many people have died in this pandemic so far," he said. "But thousands are alive today, they avoided death, they avoided the intensive care unit, they avoided the hospital because of their own good sense in coming forward for the vaccine. And because of the protection that the AstraZeneca vaccine and others have afforded to us."
He added: "We now see very clear evidence that these vaccines are transmission blocking so there will be other people who have been spared Covid-19 because of the actions of others in getting vaccinated and through that process not transmitting it on to that person."
He said younger people were “young and sociable” and “therefore they have a higher propensity for transmission”.
Asked if someone under 40 who turns up for a vaccine and is offered AstraZeneca can re-book to get a different one, Professor Van-Tam said that is “a bit of a theoretical argument”.
He said: "I am very assured that the NHS will be able to enact the JCVI recommendations, without impacting scale.
"But in this country, we don’t force people to have medical treatments. We don’t force people to have vaccines.
"We never have done, and I don’t anticipate we’re going to start any time soon."
Up to April 28, the MHRA had received 242 reports of blood clots accompanied by low blood platelet count in the UK, all in people who had AstraZeneca, out of around 28.5 million doses given.
These clots occurred in 141 women and 100 men aged from 18 to 93, and the overall case death rate was 20%, with 49 deaths. Six cases have been reported after a second dose of the vaccine.
A particular type of brain blood clot – cerebral venous sinus thrombosis (CVST) – was reported in 93 cases (with an average age of 47), and 149 had other major thromboembolic events (average age 55) accompanied by low blood platelet count.
MHRA chief executive Dr June Raine said there is a “very small difference emerging” in occurrences of rare blood clots in men and women.
She told the briefing: "It’s something that we at the MHRA are monitoring very carefully indeed. As you probably recall, we initially thought that an apparent difference in these extremely rare blood clots with low platelets – more preponderance in women – was due to the way that the vaccine was deployed.
"But we now know there is a very small difference emerging, and that is something we’re looking into very carefully indeed so that the appropriate advice can be given.
"But there are two key points there – one is that these are extremely rare, and (the other is) that any difference we’re looking at now is a small difference and one that we need to thoroughly investigate."
She added: "Public safety is always at the forefront of our minds and we take every report seriously.
"Our position remains that the benefits of the Covid-19 vaccine AstraZeneca against Covid-19, with its associated risk of hospitalisation and death, continues to outweigh the risks for the vast majority of people.
"The balance of benefits and risks is very favourable for older people but is more finely balanced for younger people and we advise that this evolving evidence should be taken into account when considering the use of the vaccine, as JVCI has done."
According to Public Health England (PHE), the vaccine programme is estimated to have prevented more than 10,000 deaths in England alone by the end of March.
Health experts are urging everyone who has had a first dose of AstraZeneca and not suffered a clot to have a second dose of the same jab, irrespective of their age.
The MHRA said that, as a precautionary measure, anyone who has a severe headache which is not relieved with painkillers or is getting worse, should seek prompt medical attention at any point from around four days to four weeks after vaccination.
People who experience the following symptoms after receiving a vaccine should also seek medical attention:
A headache that feels worse when a person lies down or bends over
A headache that is unusual and occurs with blurred vision
Feeling or being sick
Weakness or drowsiness
A rash that looks like small bruises or bleeding under the skin
Shortness of breath
Persistent abdominal pain.
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