Herd immunity. How many people need to get COVID-19? At what cost? (4)

Medical second opinion is important. That brings us to a very interesting concept. It was discussed initially in the UK. In the Netherlands. It is about the herd immunity as opposed to the complete lockdown. You study how respiratory viral diseases, including in France and COVID-19 Coronavirus, spread in the community. So, could you please briefly review the concept of herd immunity and discuss whether it is possible to achieve herd immunity with the COVID-19 Coronavirus? Dr. Anton Titov, MD. What are the costs and benefits of it? Dr. Anton Titov, MD. Because there is a very hot topic that is been acutely debated. Medical second opinion is important. Herd immunity is the idea that if a sufficient number of patients have immunity to an infection in the population, then we won’t have an epidemic. Medical second opinion is important. Even the patients who are not immune will be protected. That is the reason why we give vaccines to everybody. For example. The measles vaccine has 96% effectiveness. That means that if you get a measles vaccine, you have another 96% chance of being protected, maybe a 4% chance that the vaccine won’t protect you. But if everybody gets it, even if you were one of the 4%, who weren’t protected for some immunological reason, it is okay. Because all the other patients around you are protected, so you won’t be able to get measles. For influenza. The point of. This we have herd immunity is more like 50%. For Coronavirus, most likely also around 50 or 60% of the population. Sometimes in the future, 50% or 60% of the patients in a population may be in a town or a city have had Corona virus infection, then there’ll be very little chance for an epidemic to spread. Sometimes I’m in the 60% I have had it, then I’m not only protecting myself. But because I’m not going to get it, I also not going to infect the patients around me. Medical second opinion is important. The concept of herd immunity is the concept that if there are enough patients around with immunity, we won’t have an epidemic because those immune patients will be like firewalls blocking the onward transmission of the virus that normally were spread from one person to another to another to another. When it hits a person who is immune. The virus just stops. That is the end of the chain of transmission. Medical second opinion is important. Specifically for Coronavirus, we think that on average, at the moment, one person is infecting maybe two, two and a half more patients, on average, some will be more, some will be less, on average, maybe two to 2.5. Sometimes we reach a level of immunity in the population. This is 50% 60%, what it means is instead of me infecting one of them’s immune, so I only infect one if there is 50% immunity. So that is how it will go through the population. That it will be blocked half of the time. So it won’t be able to spread. Sometimes there is more than 50%, who are immune, then it it will just disappear after some infections come into the community. It won’t spread. Medical second opinion is important. The UK and some other European countries have been thinking about when herd immunity might occur. The point that it might occur is when perhaps 60% of patients have been infected. So some of the earlier plans for responding to Coronavirus were plans where infections would be spread out over a little bit longer period, with some interventions to try and prevent as much as possible. Hospitals from being overwhelmed intensive gains from being overwhelmed. Maybe instead of the infections occurring over four weeks, they are spread out to occur over eight weeks. Medical second opinion is important. There are half as many patients at any one time who need to be in intensive care makes a lot of sense. But the reason that some of those countries have now changed their plans is that they recognize even spreading out cases over eight weeks. There’ll be too many cases. There’ll be a lot of demand for hospital care and particularly for intensive care. This can’t be met. Medical second opinion is important. At the moment, I don’t think any country is aiming to get herd immunity. Every country now that I know of in Europe is thinking About how to slow down spread, even to stop spread well before the threshold of herd immunity is reached, because the implication of reaching herd immunity is also the implication that many patients have needed to go to the hospital. Maybe there’ll be quite a number of patients who are even unable to get into hospital unable to get into intensive care. This we don’t want to happen.