Would like any information on the crawl of virus or any other science topic you should really check out our podcast you can get it wherever you get your podcast you can also find us at twitter dot com look for it slash science. A vaccine remains elusive. But catching the corona virus can lead to immunity. And infection triggers the creation of antibodies to try to fight off the disease and prevent its return. But the question is for how long. Estonia is testing Digital Immunity passports so people not anti bodies can return to work but is that safe. Some scientists believe herd immunity is the answer they say up to 70 percent of the population must be immune to wipe out of the virus. But antibody tests are only just starting. And a new wave of infections could hate. Welcome to 19 special harmonica jones good to have you with us sweden is among the countries that have opted against a lock down and instead gone for herd immunity and this strategy has arguably led to one of the highest per capita death tolls in the weld but very little immunity made in stockholm its that special time of year when swedes hit the streets after the long dark cold swedish winter but this spring theyre asking themselves whos got the coronavirus and whos a new in the government taking a risk by keeping the country open. Ensuring broad immunity 1st we as soon as possible is an aim of chief epidemiology Anders Tegretol but only 7. 3 percent of stockholms inhabitants have developed antibodies to the virus so few have been infected thats the interim result of a study conducted by the state Health Authority at the beginning of may the percentage is less than they hoped for a reason to rethink the strategy no says anders tegan. I think the swedish structure has proved them to be sustainable i mean we get figures now that people are actually increasing. Their heroes to all those words decrease and those are high level of acceptance in the swedish population for what we do. Tangle assumes that almost a month after the study about 20 percent of the population in stockholm has now developed immunity to the corona virus but critics say that with some 4000. 00 deaths in a population of 10000000 sweden has one of the highest corona mortality rates in the world that immunization rate for children and young people nationwide was only 4. 7 percent far below the stockholm average the swedish government hopes a vaccine will soon be available. The dirty yes on the beat you know it will certainly take some time before we get there when we have sweden will have access to the facts. And we have a plan for who should be vaccinated and in what order. Board. That the nation would be safer in the natural immunization and its neither clear whether those infected with the coronavirus really are immune nor for how long. David nabarro is the cobia 900 special envoy of the World Health Organization and he joins us now good to have you with us so we hear every day about the latest case numbers we know the number of those who died and those who acuity but how many are immune to covert 9000 by now. The case numbers that we have are actually a reflection of the number of people who have been tested and found positive there are probably many more people who have had kovi did than these numbers suggest that the question is if you had kovi are you also immune to getting it again there was some uncertainty about this a few weeks ago but it looks as though if youve had covert you do have a degree of immunity how long does that Community Last we dont know so im going to be a little bit imprecise here and say that the actual number of people whove had kind of aid and who are immune to toe bid in any community is not fully know and because we dont think that large numbers of people have copd without symptoms we suspect that probably the number of people who have covered is as many as the number of people who have had symptoms of covidien and in most populations that does not seem to exceed 10 percent right now by well sort of the question that the that also means that the number of immunity could be higher than what we know already but at the same time you mention it already we dont know how long this immunity last in a study from the university of amsterdam says that they think immunity to reinfection from corona virus may only last 6 months that means immunity is at best only temporary. I think i wish that there was more precision in the answers to this kind of question because its absolutely essential when governments are making policy about whether or not they are going to have things like passports that show whether or not people are immune so right now we do not know how long immunity last if there is immunity and secondly we dont know where everybody gets it so we have to continue behaving as though even if you had kobe the u. S. Still at risk of getting it again i would just as lieve countries like sweden or at some point also britain who were aiming for herd immunity has that approach failed. I think that the u. K. Does not wish to suggest to anybody that aiming for immunity was a policy it was an idea that was suggested in a number of press briefings in months so i dont think any country in the world is actually saying we should aim for herd immunity are you letting everybody get in and then hoping that immunity builds up in the population the costs of doing so in terms of lives lost and in terms of overloading of Health Services is very great right i do not but if this policy is being used anywhere its time i know of course we all hope that ideally there will be a vaccine that as we also know that could take a while and i ask you about that in a moment but 1st a quick look at where we stand. Over 130. 00 Research Teams around the world are racing to develop a coronavirus vaccine. Some are using any negative version of sars cove 2. Others are using genetic sequences from the virus a dozen of the teams have developed serums to test on humans. This excess can move Financial Markets stock in u. S. Firma surged after reports its vaccine had triggered an immune reaction with little or no side effects but the shares plummeted when reports emerged the vaccines effectiveness was exaggerated. Researches need to run tests on thousands of subjects in any vaccine study to obtain meaningful results that takes time. Experts predict attacks a nation could be approved by the 2nd half of 2020. David nabarro from the World Health Organization vaccines can take yes but if one becomes available this year would you take it. I want to know a lot about a vaccine before i decide whether or not im going to take it 1st of all has its safety been demonstrated in a variety of different individuals particularly in individuals whove had kobe before are they going to get a hypersensitivity to it has its efficacy been demonstrated does it provide immunity that protects against infection against kobe and does it provide long term immunity or not those are the kind of questions id want to ask if i was going to decide whether or not to take the vaccine now the more likely outcome of course is that there wont be a vaccine for some time what happens then then what we have to do is to learn as humanity to live with the constant threat of this virus will need to modify our behavior including physical distance and and also taking great care of those who are most at risk and also will need to be able when necessary to take focus to action to restrict movement and to deal with outbreaks when they build up but as weve learned if you do this quickly and indeed if you do this robustly life can go on we dont need to have more lockdowns all right life can go on i like that message David Nabarro there from the World Health Organization thank you so much. And now its time for our science correspondent Derek Williams to answer some of your questions. 10 deaths from other pathologies are sometimes being classified as cause at 19 if that were true wouldnt it be reflected in fewer deaths from other pathologies tracking deaths and exactly what caused them has proved very challenging in this pandemic we mostly hear about how many people have tested positive for cope at 19 and how many people have died from it from those people who tested positive but but those statistics only reflect how many people are being tested not hell many people are actually sick or how many actually died due to the disease a more accurate overview could probably be based on whats called all cause mortality comparing numbers of how many people die in a specific place over a specific period those are numbers that we can track accurately like researchers did in a recent study looking at a small town in northern italy that showed that at the height of the crisis there in march people were dying over 10 times more frequently than they did in the town on average during that month now thats pretty eye opening there were many many more deaths across the board and many of those deaths were not necessarily being counted as covert 19 victims because the people who died werent tested. How many mutated covered 19 strains have been identified by reeses mutate regularly and if those mutations cause major differences in their virulence or their transmissibility experts begin talking about different different strains like they do with influenza but that strains is kind of a vague term in the world of viral ag. Some studies have sought to show that various lineages of the stores close to family in different parts of the world have not changed in. That we can call them different strains although theres plenty of evidence of of evolved changes in the virus at the genetic and the most like your levels there isnt really evidence that those changes have altered its biology with whats called it ciro type which which describes how our immune system responds to the pathogen and for us thats the key point. There is there and hell be back to answer more of your questions tamara just post them on our you tube channel for the use as a keep up with the latest developments on the coronavirus you can always subscribe to our newsletter go to d w dot com slash corona cash newsletter and fill out the form. And thats all falco good night its special for today i want to get johns of the men from me on the team thanks for joining us. To go. Lots of goals are met with silence the 2nd bundesliga match day empty stadium. Leaders by a unique trounce frankfurt. Paris up beilein beat local rivals. On top of. More. Nor. What do they dream of at night or even. As cleaners they see the face of horror. Their job since ring for the social media industry. In manila there are thousands of socalled content monitors day for day they scream terrifying images from online platforms. Up to 20000 times a day a risky job for starvation wage. The strain is enormous. The cleaners or sworn to secrecy they are not allowed to talk about their work. And no one asks how they are doing. I quit. I need to stop or something wont. Do social networks have any social responsibility at all. The cleaners social medias shadow industry starts junee on t. W. Well can some much take 27 the 2nd since the bundesliga restarts. Lets be honest it still feels