Using antibodies to treat COVID
When Donald Trump caught coronavirus, you might recall that one of the treatments he received was an experimental cocktail of covid antibodies designed to give his immune system a helping hand to fight the virus. At the time, there wasn’t much evidence for the effectiveness of this therapy, but now researchers at Oxford University have announced initial results from a trial conducted on thousands of Covid patients treated by the NHS. Given early, it seems, and to the right recipients, these lab-made antibodies can save lives. Martin Landray spoke to Chris Smith about how it works…
Martin - So these antibodies are, if you like, copies of human antibodies and a company in this case, Regeneron, screen through lots and lots of antibodies to find the ones that bind the tightest to the key parts of the so-called 'spike protein' on the outside of the Corona virus that causes COVID. So they selected, if you like, the best two and then made them in very large quantities in a manufacturing plant. And then we use that as a treatment, which we then give to future patients. And those patients are given the treatment as an intravenous drip over about an hour.
Chris - So this is a cocktail of two different types of antibody, both of which target the virus, but coming at it from slightly different angles, so they bind onto different bits of it?
Martin - Yeah. They bind on to slightly different parts of the so-called 'spike protein', this sort of the sticky out bit on, I guess we've all seen the photographs and the images in the papers. The reason for using two, is a sort of belt and braces approach. If there was a mutation in the virus, if there's a new variant, then that might impact the ability of one to bind, but wouldn't impact on the ability of the other. It's a belt and braces if your belt fails, but your brace is intact, your trousers still stay up.
Chris - And what were you testing?
Martin - So we were testing whether, amongst the patients who have COVID and come into hospitals, whether this antibody drug would reduce the chances of dying, perhaps improve the speed at which people get out of the hospital and so on. And so nearly 10,000 NHS patients as they came to hospital and volunteered, and we did, what's called a randomized trial. You toss a coin and if it comes down, let's say heads, then the patient's got this extra drug on top of all the best that the NHS can offer. And it comes down tails, they got the best the NHS can offer, but without this drug. And what we found is that this antibody drug worked really very well in a particular type of patients. We are all supposed to produce antibodies in response to an infection with coronavirus, but some people somehow, for whatever reason don't manage to do so, or it's somewhat delayed. So these patients get sick and they haven't got good antibodies of their own. And what we found was if we use the antibodies in the drug and give those to patients who don't have their own antibodies, actually we can reduce the risk of dying. We can shorten the hospital stay, which is also great. And we can reduce the need for those patients to go onto a ventilator. So if you like in this group of people who are at high risk, they're not fighting the infection well for themselves because they don't have antibodies. If you give them antibodies, then their chances of a good outcome are substantially improved.
Chris - What's your window of opportunity to get in there with these therapeutic antibodies in order to achieve those improvements?
Martin - Really, I think within the first 24 hours or 48 hours of people coming into hospital would be, I think how this will get rolled out. So this is how it will be delivered in the future. So I can well imagine in the very near future patients who go, sick enough to go to hospital with COVID will not only have a nose and throat swab to test for the virus, but they'll also have a blood test for antibodies. And if they don't have antibodies of their own the treatment would then be given.
Chris - And how big a difference can this make?
Martin - Well, what we see is that the people who have not fought the infection properly for themselves, probably the risk of dying is in the order of 30%. So nearly one in three patients, sadly, don't survive the hospital admission. If the drug is given to these people, then we reduce that down to about 24%, so that's an improvement of a fifth.
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