Home » Coronavirus » COVID-19 vaccine clinical trials. Hopes, risks, and methods. (6)
COVID-19 vaccine clinical trials. Hopes, risks, and methods. (6)
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Successful vaccines for COVID-19 Coronavirus is what everybody hopes for. And you’re an expert in assessing vaccines, and especially vaccine safety, adverse reactions and nonspecific effects of vaccines. And what do you think of their vaccine efforts against COVID-19? How likely are vaccine efforts to be successful? Will speed of development cut corners on safety? And some say that effective vaccine against COVID-19 will never be found. What do you think of that? So, when it comes to vaccines, we have to be not only careful in ensuring that we trial people sufficiently, but when we first introduced the vaccine, we’ve got to be really careful in making sure that adverse effects are not slipping under the radar. We’re good enough at detecting them and that we have surveillance for so the For example, back in 1976, when there was a major flu epidemic in the US, the vaccine that many people had possibly caused some excess of a rather nasty disease called Guillain Barre syndrome in which people can effectively become paralyzed. They usually recover from this after a while, but sometimes their recovery means that they’ve got an ongoing weakness, and not everyone recovers, but people usually do. So in particular, when we had the pandemic flu in 2009, we were very concerned that when the vaccines for that flu were being given to very large numbers, there were no extra cases Guillain-Barre syndrome, and certainly in Europe. I believe in the rest of the world. There was very careful surveillance to ensure that we were not having cases of Guillain Barre syndrome that we had seen with a previous flu vaccine. So our problem is that we want to get vaccines to prevent disease. But we need to study large numbers. And when we first put a vaccine out into the population as a whole, we only know for certain, a limited range of the possible harms that can cause and so we need to carry out surveillance. And we have to be aware that sometimes we’ll be caught out. I think that the speed of development of vaccines, I don’t think I don’t think I know that the speed of development of vaccines for COVID-19 is faster than we’ve done for any other disease. Ever. The energy and effort and the thought and the clever approaches that have gone into finding vaccines for these, and the speed with which they’ve been done might lead us to be worried about cutting corners on safety. There is a danger that this can happen, but I think it is minimal danger. Those who develop vaccine vaccines are very conscious that if they put a vaccine out, that causes more harm than good, they will be in big trouble. And so they are cautious. So the speed with which we’re doing it is partly because our technology has advanced and we have techniques of getting vaccines ready. piggybacking on the previous knowledge we have, being able to slot a new little bit of a virus into an existing vaccine. As a consequence, we can actually get the vaccine ready to be tested quicker. There’s a lot of the disease about So in principle, we can find what is likely to be effective. But there are some elements of this that just can’t have a shortcut. We have to study people. We can’t say, within a week, the outcome will be up one month or six months. So we may need three months or six months follow up to be sure that the effects we’re seeing are either lasting, or we’re not seeing adverse effects that only appear after one or two or three months. So some things can’t have a shortcut. So I have slight concerns that we’re all in such a hurry and the pressures are great to get a vaccine. But I don’t think that I have major concerns. It’s possible. An effective vaccine may not be found. We have over 100 vaccines being tested. Eight of them, at least, are in phase one, phase two trials at the moment. And I think it’s quite likely that we will find a vaccine. We do not know how efficacious it will be, but it may not prevent even 90% of diseases. But if it presents prevents 80 or 70, or even 60%, maybe even 50% of cases, it might be regarded as worthwhile. The economic costs to the whole world are enormous of this disease. And so having a vaccine that even presents some of the disease will be worthwhile, but we have no guarantee that we will find one, but our basic knowledge and already the data that we have shown that the vaccines are producing antibodies that we would expect result in reducing at least the severity of the disease, if not preventing it totally. Nobody can say a vaccine will never be found. We have good evidence that it is difficult. It is difficult to produce the antibodies, and it is not certain how long the effectiveness will last. So, the possibility that the vaccine does not prevent all the disease does not necessarily mean a vaccine will be no good if it reduces the severity of disease In a sufficiently large proportion of the people who get the vaccine, then that will be useful. We can’t guarantee we’ll find such a vaccine without having unwanted effects adverse effects that are too great. But all our expectation is or not simply our optimism, but all our expectation is that we will find a vaccine among the many possibilities that are being trialed. A major problem, of course, would be that for some vaccines, notably some flu vaccines, their efficacy is reduced in the very elderly. And if we found that the vaccine against COVID-19 had reduced efficacy in the very elderly, they are the people who are most affected by COVID-19. And so the vaccine would not have as much you utility. However, again, if we found a vaccine that was very effective and worked in children and in young adults and middle-aged adults, and you could prevent the disease circulating in them, that would end up protecting elderly people who are not being protected by the vaccine itself. If sufficient numbers in the population are immune to SARS-CoV-2, then we will find that it is no longer circulating; and we protect the health of those who are most at risk.
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