ウィスパリング同時通訳研究会コミュのAstraZeneca vaccine - Under 30s to be offered alternative vaccines, say MHRA

23:45
Jonathan Van-Tam: (00:08)
Welcome to the Department of Health and Social Care from where this briefing is being delivered. I’m Jonathan Van-Tam, Deputy Chief Medical Officer and this is a clinical and scientific briefing. I’m joined today on my right by Professor Wei Shen Lim, chair of the Joint Committee on Vaccination and Immunisation, the JCVI. To my immediate left by Professor Raine, Chief Executive Officer of the MHRA. And to my extreme left by Professor Munir Pirmohamed, who is chair of the Commission on Human Medicines.
(00:53)
So today’s briefing is about the UK vaccine program. In particular, it is about the AZ vaccine. We will explain as we go through about a change of course, a course correction if you like to the UK program. Now, if you could have said to me back in March, 2020 and predicted how far we would have come so far with our vaccine program, then I’m not sure I would have believed that we would have got as far as we have. The UK vaccine program has been the most enormous success indeed.
(01:40)
And if you said to me that by March, 2021, we would not have needed a course correction that’s also would have amazed me. So we must keep this in context of the enormous success that we’ve achieved so far. I’m going to stop there for now and allow Professor Raine to open the briefing by explaining her perspective from the MHRA on where we are arriving at today. Professor Raine.

Professor Raine: (02:14)
Thank you, Professor Van-Tam. I will now update on MHRA’s rigorous scientific review of safety reports of very rare and specific blood clots with low platelet count thrombocytopenia associated with COVID-19 vaccine, AstraZeneca. Over 20 million doses of the AZ vaccine have been given in the UK. And we know that vaccines are the best way to protect people from COVID-19 and have already saved thousands of lives. And in fact, around 6,000 modeled in the UK by the end of February, but no effective medicine or vaccine is without risk. And with vaccines more complex than usual because the benefits can be to people other than the individual taking the vaccine.
(03:03)
Well, the clinical trials of vaccines allow us to assess relatively common effects. Very rare effects are only detected when a vaccine is used at scale on a large enough number of people and that is why the UK has careful monitoring systems in place and these monitoring systems are now detecting a potential side effect of the COVID-19 vaccine, AstraZeneca in an extremely small number of people. The evidence is firming up and our review has concluded that while it’s a strong possibility, more work is needed to establish beyond all doubt that the vaccine has caused these side-effects.
(03:45)
Our role is to continually monitor safety during widespread use to confirm that the vaccines are performing as expected to identify any very rare side effects and to ensure the benefits outweigh the risks. The public’s safety is at the forefront of our minds. Our teams of safety experts, scientists, clinicians, and epidemiologists have investigated, reviewed, and evaluated thoroughly and scientifically all safety reports. And our safety rubric reviews are carried out in tandem with the vaccination program. We’ve gathered a large amount of data on the safety profile of the available vaccines, and we’ve done a rigorous scientific review of all the available data with regards to suspected blood clots with low platelet count.
(04:35)
The Commission on Human Medicines Expert Working Group has also met frequently and critically assessed all the data alongside our regulatory review. And this has also included lay representatives and advice from leading hematologists. Based on the current evidence, the benefits of the COVID-19 vaccine AstraZeneca against COVID-19 and its associated risks, hospitalization and death continues to outweigh the risks for the vast majority of people.
(05:09)
Our review has reinforced that the risk of this rare suspected side effect remains extremely small. By the 31st of March, over 20 million doses having been given, we have had 79 case reports up to and including that date, 31st of March. All 79 cases occurred after the first dose. Of these 79 cases, 19 people have sadly died. These cases occurred in 51 women and 28 men, age from 18 to 79 years. And from these reports, the risk of this type of rare blood clot is about four people in a million who received the vaccine. Three out of the 19 were under 30 years. 14 of the 19 were of the cerebral venous sinus thrombosis with low platelets and five were other kinds of thrombosis in major veins.
(06:07)
The balance of benefits and risks is very favorable for older people, but it is more finely balanced for the younger people. And we at the MHRA are advising that this evolving evidence should be taken into account when considering how the vaccine is used. Today we’ll be communicating information and advice to healthcare professionals on how to minimize risks. And this will provide a lot of guidance, including how to report any suspected cases.
(06:38)
The information for healthcare professionals will be updated and there will also be information for the public. Things to look out for as we continue to monitor this issue. Anyone who has symptoms four days after vaccination or more should seek prompt medical advice. A new onset of a severe or persistent headache or blurred vision, shortness of breath, chest pain, leg swelling, persistent abdominal pain, or indeed unusual skin bruising or pinpoint spots beyond the injection site.
(07:10)
So Professor Sir Munir will outline the Commission on Human Medicines further advice, but I’d like to reiterate again that this is extremely rare. And with the proven effectiveness against the disease that is still a huge risk to our population, the balance of benefits and known risks of the vaccine is still very favorable for the vast majority of people. So Professor Sir Munir, over to you.

Prof. Munir Pirmohamed: (07:39)
Thank you very much, June. So I’ve worked with the Commission on Human Medicines and the Expert Working Group separately to thoroughly review are all the cases coming in with the Oxford AstraZeneca vaccine in the UK. We’ve taken into account a wide range of data sources. We’ve looked at information about the usage of the vaccine on various age groups and updated incidents rates and benefit risk comparisons for different populations by age and gender.
(08:10)
Over the last couple of weeks, the two committees have spent almost 24 hours in committee reviewing these reports. Each report has been carefully scrutinized by them MHRA and by the members of the Working Group and further information has been obtained where necessary. We’ve also had independent adjudication of these cases by an expert hematologist and we worked with another group of hematologists to develop a case definition of these events to make sure that the cases were identified throughout the UK and reported via the yellow card scheme.
(08:46)
Based on the currently available data, the Commission on Human Medicines is advising the following. First, a pregnant woman should continue to discuss with the healthcare professional whether the benefits of having the vaccine outweigh the risks for them. Number two, people with a history of blood disorders that increase the risk of clotting should only have the COVID-19 vaccine AstraZeneca when the benefits outweigh any potential risks.
(09:14)
Number three, anyone who experienced cerebral or other major blood clots occurring together with low levels of platelets after the first vaccine of COVID-19 AstraZeneca should not have the second dose. We will be continually monitoring further reports as they come in, continually monitoring other aspects to identify risk factors so that we can refine the advice that we give. At present, the data on people who’ve had two doses of the COVID-19 AstraZeneca vaccine are limited because these events are rare and comparatively small number of second doses have been given.
(09:56)
Therefore, it is not possible to draw a conclusion about how frequently blood clots with a low platelet count happened following a second dose of the vaccine, but this will be monitored closely by the MHRA and by the CHM as part of the ongoing review. So just to put into context, these events are extremely rare as June has already mentioned. And I want to put it into context in relation to COVID-19 itself.
(10:22)
It is important to remember the COVID 19 itself causes clotting and it causes lowered platelets. And I’ve got a few figures from a paper which was recently published. Pulmonary embolism, clots on the lungs occur in 7.8% of people who have COVID-19. DVT, deep venous thrombosis, clots in the legs occur in 11.2%. who’ve had COVID-19 and of those people who’ve been infected with SARS-COVID-2 getting COVID-19 and ending up in ITU, 23% will have some form of clot.
(10:59)
COVID- 19 also causes strokes in about 1.6% and up to 30% of people who develop COVID-19 will get thrombocytopenia, which is lowering of the platelet count. And that puts into context that the risk of clots and load platelets is much higher with COVID-19 than these extremely rare events, which are occurring with the vaccine. So to finish off, the CHM has advised that the link between the vaccine and blood clots in the cerebral and other veins occurring together with lowered platelets is getting firmer, but absolute proof of the link between the vaccine adverse events will need extensive scientific work.
(11:41)
Based on the currently available evidence the benefit-risks remains favorable for the vast majority of people, but as June said, is more finely balanced for the younger people. We are advising that this evolving evidence should be taken into account when considering the use of the vaccine. I’ll hand back to Professor Van-Tam.
(12:02)
Thank you, Professor Sir Munir. Thank you, Professor Raine. You’ve now heard from the regulatory experts and in a moment, I will turn to the new advice from the JCVI with Professor Lim. But before we do that, I’d like to put into context in a visual way what the data are telling us in terms of benefits and risks. So if I could have the first slide, please.

Jonathan Van-Tam: (12:32)
So this side, and I’ll go through the first one slowly, shows you in blue type to the left of the slide, the potential benefits from COVID-19 vaccination and on the orange parts to the right, the potential harms. And you can see that as you go down the slide from top to bottom, those benefits and potential harms are arrayed by age band, starting at 20 to 29, young adults, through to 60 to 69, relatively old adults. And the way these data have been arrayed are in terms of intensive care admissions prevented via vaccine on the left, and serious harms potentially due to the vaccine on the right. And I thank colleagues at the Winton Centre for Risk and Evidence Communication at Cambridge University for help with getting this slide together.
(13:42)
This first slide is set, as you can see from the title, in a scenario of low exposure, and in actual fact, the rates of disease assumed in this scenario are lower than those we currently have in the UK at the moment. And you can see that if you look at the 20 to 29 age band, then the potential benefits amount to 0.8 ICU admissions averted compared with serious harms of potentially 1.1.
(14:21)
But as you go up through the age groups, the amount of serious harm declines, but the amount of benefit in terms of averted ICU admissions becomes much more pronounced. And these are arrayed over a 16 week period. Now, we don’t expect vaccine to last for 16 weeks. We very confidently expect that it is going to be many, many months of protection from a vaccine. And the reason for using 16 weeks is because that is a typical pandemic wave. That’s the duration of it. But you can see that at a very low exposure risk, lower than we have in the UK at the moment, the risk benefit is relatively finely balanced in those younger age groups, but it becomes very overwhelming in favor of vaccine as you go up the ages.
(15:25)
If we go onto the next slide, please. This is now a medium risk scenario, and it is set at 60 cases per 100,000. That is marginally higher than the UK average at the moment, but it is lower than some of the remaining hotspots in the UK. And you can see that when the disease is around us more, when there’s more exposure, then the benefits, the potential benefits, start to stack up, but the potential serious harms remain static, of course. And this is still over a 16 week period, and you can see that the data become more overwhelming in terms of vaccine benefit.
(16:16)
Finally, let’s move to a high exposure risk. And this one… Next slide, please… is set typically at where we get to in terms of a pandemic wave. This is set at the height of the second pandemic wave that we went through in the last few months, and I think is reflective of the kind of scenario we want to avoid in the forthcoming autumn and winter if we possibly can.
(16:49)
But here, when there’s a lot of COVID-19 circulating in the population, you can see that even in the 20 to 29 group, the potential benefits in terms of intensive care admissions averted is very much higher than the serious harms due to vaccine, and that’s why the regulators have concluded as they have about risk benefit for the AstraZeneca vaccine.
(17:20)
So, I hope that’s placed it all into a bit of context for everybody. I recognize it’s been a detailed, scientific discussion so far, but hopefully those figures bring it to life. And at this point, I’m going to hand over to Professor Lim to give us the JCVI advice. Thank you, Wei Shen.

Professor Wei Shen Lim: (17:40)
Thank you, Jonathan. JCVI has been meeting over the last two weeks and we have carefully and independently reviewed the safety evidence and the benefit evidence given to us from MHRA and Public Health England, and that includes some of the kinds of data that you seen earlier on the slide.
(18:03)
We are well aware of the high level of protection that COVID-19 vaccines provide, particularly against serious disease, that is hospitalization, ITU admission, and from dying from COVID-19 disease. Against that must be balanced the uncertain occurrence of an extremely rare adverse event that may be associated with vaccination. Acting really in the interest of safety and for public benefit, JCVI feel that there are three points of advice that we would like to put across.
(18:38)
The first is that information given to individuals who are being offered vaccination and information given to health professionals should be appropriately updated to reflect the latest considerations and deliberations by JCVI and by MHRA.
(18:57)
The second point is that those who have received their first dose of AstraZeneca vaccine should continue to be offered the second dose of AstraZeneca vaccine, according to the set schedule.
(19:11)
And the final bit of advice is that adults who are aged 18 to 29 years old, who do not have an underlying health condition that puts them at higher risk from serious COVID-19 disease should be offered an alternative COVID-19 vaccine in preference to the AstraZeneca vaccine, where such an alternative vaccine is available.
(19:36)
And perhaps it’s useful to state what is not advised as well. We are not advising a stop to any vaccination for any individual in any age group. We are advising a preference for one vaccine over another vaccine for a particular age group, really out of the utmost caution, rather than because we have any serious safety concerns. This will obviously have some implications in terms of operation and deployment of vaccines and I’m just going to hand back, therefore, to Jonathan, to set those out for us.

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