Alice and Bob compete. Bob wins convincingly both times. But overall, Alice is better. How come?
This happens for real in medical trials and cases where you don't have much control over the size of groups you test on:
Trial 1 Score
Trial 2 Score
The points to notice:
• In each trial, they got different sized groups assigned to them. There can be good reasons for this. One procedure may be known (or thought) to be better for specific circumstances so it would unethical to assign procedure based on “we want to simplify our statistical analysis” rather than on best possible outcome. Or you may simply be combining statistics about things not in your control.
• Alice's score for her largest group is better than Bob's score for his largest group, but those ‘largest groups’ were in different trials so they only ever get compared in the overall figure.
On the third Friday of January a silent and stealthy killer was creeping across the world. Passing from person to person and borne on ships and planes, the coronavirus was already leaving a trail of bodies.
The virus had spread from China to six countries and was almost certainly in many others. Sensing the coming danger, the British government briefly went into wartime mode that day, holding a meeting of Cobra, its national crisis committee.
But it took just an hour that January 24 lunchtime to brush aside the coronavirus threat. Matt Hancock, the health secretary, bounced out of Whitehall after chairing the meeting and breezily told reporters the risk to the UK public was “low”.
This was despite the publication that day of an alarming study by Chinese doctors in the medical journal The Lancet. It assessed the lethal potential of the virus, for the first time suggesting it was comparable to the 1918 Spanish flu pandemic, which killed up to 50 million people.
Unusually, Boris Johnson had been absent from Cobra. The committee — which includes ministers, intelligence chiefs and military generals — gathers at moments of great peril such as terrorist attacks, natural disasters and other threats to the nation and is normally chaired by the prime minister.
Johnson had found time that day, however, to join in a lunar-new-year dragon eyes ritual as part of Downing Street’s reception for the Chinese community, led by the country’s ambassador.
It was a big day for Johnson and there was a triumphal mood in Downing Street because the withdrawal treaty from the European Union was being signed in the late afternoon. It could have been the defining moment of his premiership — but that was before the world changed.
That afternoon his spokesman played down the looming threat from the east and reassured the nation that we were “well prepared for any new diseases”. The confident, almost nonchalant, attitude displayed that day in January would continue for more than a month.
Johnson went on to miss four further Cobra meetings on the virus. As Britain was hit by unprecedented flooding, he completed the EU withdrawal, reshuffled his cabinet and then went away to the grace-and-favour country retreat at Chevening where he spent most of the two weeks over half-term with his pregnant fiancée, Carrie Symonds.
It would not be until March 2 — five weeks later — that Johnson would attend a Cobra meeting about the coronavirus. But by then it was almost certainly too late. The virus had sneaked into our airports, our trains, our workplaces and our homes. Britain was on course for one of the worst infections of the most insidious virus to have hit the world in a century.
Last week a senior adviser to Downing Street broke ranks and blamed the weeks of complacency on a failure of leadership in cabinet. The prime minister was singled out.
“There’s no way you’re at war if your PM isn’t there,” the adviser said. “And what you learn about Boris was he didn’t chair any meetings. He liked his country breaks. He didn’t work weekends. It was like working for an old-fashioned chief executive in a local authority 20 years ago. There was a real sense that he didn’t do urgent crisis planning. It was exactly like people feared he would be.”Inquiry ‘inevitable’
One day there will be an inquiry into the lack of preparations during those “lost” five weeks from January 24. There will be questions about when politicians understood the severity of the threat, what the scientists told them and why so little was done to equip the National Health Service for the coming crisis. It will be the politicians who will face the most intense scrutiny.
Among the key points likely to be explored are why it took so long to recognise an urgent need for a massive boost in supplies of personal protective equipment (PPE) for health workers; ventilators to treat acute respiratory symptoms; and tests to detect the infection.
We have talked to scientists, academics, doctors, emergency planners, public officials and politicians about the root of the crisis and whether the government should have known sooner and acted more swiftly to kick-start the Whitehall machine and put the NHS onto a war footing.
They told us that, contrary to the official line, Britain was in a poor state of readiness for a pandemic. Emergency stockpiles of PPE had severely dwindled and gone out of date after becoming a low priority in the years of austerity cuts. The training to prepare key workers for a pandemic had been put on hold for two years while contingency planning was diverted to deal with a possible no-deal Brexit.
This made it doubly important that the government hit the ground running in late January and early February. Scientists said the threat from the coming storm was clear. Indeed, one of the government’s key advisory committees was given a dire warning a month earlier than has previously been admitted about the prospect of having to deal with mass casualties.
It was a message repeated throughout February, but the warnings appear to have fallen on deaf ears. The need, for example, to boost emergency supplies of protective masks and gowns for health workers was pressing, but little progress was made in obtaining the items from manufacturers, mainly in China.
Instead, the government sent supplies the other way — shipping 279,000 items of its depleted stockpile of protective equipment to China during this period in response to a request for help from the authorities there.Impending danger
The prime minister had been sunning himself with his girlfriend in the millionaires’ Caribbean resort of Mustique when China alerted the World Health Organisation (WHO) on December 31 that several cases of an unusual pneumonia had been recorded in Wuhan, a city of 11 million people in Hubei province.
In the days that followed, China at first claimed the virus could not be transmitted from human to human, which should have been reassuring. But this did not ring true to Britain’s public health academics and epidemiologists, who were texting one another, eager for more information, in early January.
Devi Sridhar, professor of global public health at Edinburgh University, had predicted in a talk two years earlier that a virus might jump species from an animal in China and spread quickly to become a human pandemic. So the news from Wuhan set her on high alert.
“In early January a lot of my global health colleagues and I were kind of discussing ‘What’s going on?’” she recalled. “China still hadn’t confirmed the virus was human to human. A lot of us were suspecting it was because it was a respiratory pathogen and you wouldn’t see the numbers of cases that we were seeing out of China if it was not human to human. So that was disturbing.”
By as early as January 16 the professor was on Twitter calling for swift action to prepare for the virus. “Been asked by journalists how serious #WuhanPneumonia outbreak is,” she wrote. “My answer: take it seriously because of cross-border spread (planes means bugs travel far & fast), likely human-to-human transmission and previous outbreaks have taught overresponding is better than delaying action.”
Events were now moving fast. Four hundred miles away in London, on its campus next to the Royal Albert Hall, a team at Imperial College’s School of Public Health led by Professor Neil Ferguson produced its first modelling assessment of the impact of the virus. On Friday January 17 its report noted the “worrying” news that three cases of the virus had been discovered outside China — two in Thailand and one in Japan. While acknowledging many unknowns, researchers calculated that there could already be as many as 4,000 cases. The report warned: “The magnitude of these numbers suggests substantial human-to-human transmission cannot be ruled out. Heightened surveillance, prompt information-sharing and enhanced preparedness are recommended.”
By now the mystery bug had been identified as a type of coronavirus — a large family of viruses that can cause infections ranging from the common cold to severe acute respiratory syndrome (Sars). There had been two reported deaths from the virus and 41 patients had been taken ill.
The following Wednesday, January 22, the government convened the first meeting of its scientific advisory group for emergencies (Sage) to discuss the virus. Its membership is secret but it is usually chaired by the government’s chief scientific adviser, Sir Patrick Vallance, and chief medical adviser, Professor Chris Whitty. Downing Street advisers are also present.
There were new findings that day, with Chinese scientists warning that the virus had an unusually high infectivity rate of up to 3.0, which meant each person with the virus would typically infect up to three more people.
One of those present was Imperial’s Ferguson, who was already working on his own estimate — putting infectivity at 2.6 and possibly as high as 3.5 — which he sent to ministers and officials in a report on the day of the Cobra meeting on January 24. The Spanish flu had an estimated infectivity rate of between 2.0 and 3.0, whereas for most flu outbreaks it is about 1.3, so Ferguson’s finding was shocking.
The professor’s other bombshell in the report was that there needed to be a 60% cut in the transmission rate — which meant stopping contact between people. In layman’s terms it meant a lockdown, a move that would paralyse an economy already facing a battering from Brexit. At the time such a suggestion was unthinkable in the government and belonged to the world of post-apocalypse movies.
The growing alarm among scientists appears not to have been heard or heeded by policy-makers. After the January 25 Cobra meeting, the chorus of reassurance was not just from Hancock and the prime minister’s spokesman: Whitty was confident too.
In early February Hancock proudly told the Commons the UK was one of the first countries to develop a new test for the virusSTEFAN ROUSSEAU/PA
“Cobra met today to discuss the situation in Wuhan, China,” said Whitty. “We have global experts monitoring the situation around the clock and have a strong track record of managing new forms of infectious disease . . . there are no confirmed cases in the UK to date.”
However, by then there had been 1,000 cases worldwide and 41 deaths, mostly in Wuhan. A Lancet report that day presented a study of 41 coronavirus patients admitted to hospital in Wuhan, which found that more than half had severe breathing problems, a third required intensive care and six had died.
And there was now little doubt that the UK would be hit by the virus. A study by Southampton University has shown that 190,000 people flew into the UK from Wuhan and other high-risk Chinese cities between January and March. The researchers estimated that up to 1,900 of these passengers would have been infected with the coronavirus — almost guaranteeing the UK would become a centre of the subsequent pandemic.
Sure enough, five days later, on Wednesday January 29, the first coronavirus cases on British soil were found when two Chinese nationals from the same family fell ill at a hotel in York. The next day the government raised the threat level from low to moderate.The pandemic plan
On January 31 — or Brexit day, as it had become known — there was a rousing 11pm speech by the prime minister promising that withdrawal from the European Union would be the dawn of a new era, unleashing the British people, who would “grow in confidence” month by month.
By this time there was good reason for the government’s top scientific advisers to feel creeping unease about the virus. The WHO had declared the coronavirus a global emergency just the previous day, and scientists at the London School of Hygiene and Tropical Medicine had confirmed to Whitty in a private meeting of the Nervtag advisory committee on respiratory illness that the virus’s infectivity could be as bad as Ferguson’s worst estimate several days earlier.
The official scientific advisers were willing to concede in public that there might be several cases of the coronavirus in the UK. But they had faith that the country’s plans for a pandemic would prove robust.
This was probably a big mistake. An adviser to Downing Street — speaking off the record — said their confidence in “the plan” was misplaced. While a possible pandemic had been listed as the No 1 threat to the nation for many years, the source said that in reality it had long since stopped being treated as such.
Several emergency planners and scientists said that the plans to protect the UK in a pandemic had once been a priority and had been well funded for the decade following the 9/11 terrorist attacks in 2001. But then austerity cuts struck. “We were the envy of the world,” the source said, “but pandemic planning became a casualty of the austerity years, when there were more pressing needs.”
The last rehearsal for a pandemic was a 2016 exercise codenamed Cygnus, which predicted the health service would collapse and highlighted a long list of shortcomings — including, presciently, a lack of PPE and intensive care ventilators.
An equally lengthy list of recommendations to address the deficiencies was never implemented. The source said preparations for a no-deal Brexit “sucked all the blood out of pandemic planning” in the following years.Play VideoWhat can we learn from the Spanish Flu?
In the year leading up to the coronavirus outbreak key government committee meetings on pandemic planning were repeatedly “bumped” off the diary to make way for discussions about more pressing issues such as the beds crisis in the NHS. Training for NHS staff with protective equipment and respirators was also neglected, the source alleges.
Members of the government advisory group on pandemics are said to have felt powerless. “They would joke between themselves, ‘Ha-ha, let’s hope we don’t get a pandemic’, because there wasn’t a single area of practice that was being nurtured in order for us to meet basic requirements for a pandemic, never mind do it well,” said the source.
“If you were with senior NHS managers at all during the last two years, you were aware that their biggest fear, their sweatiest nightmare, was a pandemic, because they weren’t prepared for it.”
It meant that the government had much catching-up to do as it became clear that this “nightmare” was turning into a distinct possibility in February. But the source said there was still little urgency. “Almost every plan we had was not activated in February. Almost every government department has failed to properly implement their own pandemic plans,” the source said.
One deviation from the plan, for example, was a failure to give an early warning to firms that there might be a lockdown so they could start contingency planning. “There was a duty to get them to start thinking about their cashflow and their business continuity arrangements,” the source said.Superspreader
A central part of any pandemic plan is to identify anyone who becomes ill, vigorously pursue all their recent contacts and put them into quarantine. That involves testing, and the UK seemed to be ahead of the game. In early February Hancock proudly told the Commons the UK was one of the first countries to develop a new test for the coronavirus. “Testing worldwide is being done on equipment designed in Oxford,” he said.
So when Steve Walsh, a 53-year-old businessman from Hove, East Sussex, was identified as the source of the second UK outbreak on February 6, all his contacts were followed up with tests. Walsh’s case was a warning of the rampant infectivity of the virus: he is believed to have passed it to five people in the UK after returning from a conference in Singapore, as well as six overseas.
But Public Health England failed to take advantage of our early breakthroughs with tests and lost early opportunities to step up production to the levels that would later be needed.
This was in part because the government was planning for the virus using its blueprint for fighting the flu. Once a flu pandemic has found its way into the population and there is no vaccine, the virus is allowed to take its course until “herd immunity” is acquired. Such a plan does not require mass testing.
A senior politician told this newspaper: “I had conversations with Chris Whitty at the end of January, and they were absolutely focused on herd immunity. The reason is that with flu, herd immunity is the right response if you haven’t got a vaccine.
“All of our planning was for pandemic flu. There has basically been a divide between scientists in Asia, who saw this as a horrible, deadly disease on the lines of Sars, which requires immediate lockdown, and those in the West, particularly in the US and UK, who saw this as flu.”
The prime minister’s top adviser, Dominic Cummings, is said to have had initial enthusiasm for the herd immunity concept, which may have played a part in the government’s early approach to managing the virus. The Department of Health firmly denies that “herd immunity” was ever its aim and rejects suggestions that Whitty supported it. Cummings also denies backing the concept.
The failure to obtain large amounts of testing equipment was another big error of judgment, according to the Downing Street source. It would later be one of the big scandals of the coronavirus crisis that the considerable capacity of Britain’s private laboratories to mass-produce tests was not harnessed during those crucial weeks of February.
“We should have communicated with every commercial testing laboratory that might volunteer to become part of the government’s testing regime, but that didn’t happen,” said the source.
The lack of action was confirmed by Doris-Ann Williams, chief executive of the British In Vitro Diagnostics Association, which represents 110 companies that make up most of the UK’s testing sector. Amazingly, she said her organisation did not receive a meaningful approach from the government asking for help until April 1 — the night before Hancock bowed to pressure and announced a belated and ambitious target of 100,000 tests a day by the end of this month.
There was also a failure to replenish supplies of gowns and masks for health and care workers in the early weeks of February — despite NHS England declaring the virus its first “level 4 critical incident” at the end of January.
It was a key part of the pandemic plan — the NHS’s Operating Framework for Managing the Response to Pandemic Influenza, dated December 2017 — that the NHS would be able to draw on “just in case” stockpiles of PPE.
But many of the “just in case” stockpiles had dwindled, and equipment was out of date. As not enough money was being spent on replenishing stockpiles, this shortfall was supposed to be filled by activating “just in time” contracts, which had been arranged with equipment suppliers in recent years to deal with an emergency. The first order for equipment under the “just in time” protocol was made on January 30.
However, the source said that attempts to call in these “just in time” contracts immediately ran into difficulties in February because they were mostly with Chinese manufacturers, which were facing unprecedented demand from the country’s own health service and elsewhere.
This was another nail in the coffin for the pandemic plan. “It was a massive spider’s web of failing; every domino has fallen,” said the source.
The NHS could have contacted UK-based suppliers. The British Healthcare Trades Association (BHTA) was ready to help supply PPE in February — and throughout March — but it was only on April 1 that its offer of help was accepted. Dr Simon Festing, the organisation’s chief executive, said: “Orders undoubtedly went overseas instead of to the NHS because of the missed opportunities in the procurement process.”
Downing Street admitted on February 24 — just five days before NHS chiefs warned a lack of PPE left the health service facing a “nightmare” — that the UK government had supplied 1,800 pairs of goggles and 43,000 disposable gloves, 194,000 sanitising wipes, 37,500 medical gowns and 2,500 face masks to China.
A senior Department of Health insider described the sense of drift witnessed during those crucial weeks in February: “We missed the boat on testing and PPE . . . I remember being called into some of the meetings about this in February and thinking, ‘Well, it’s a good thing this isn’t the big one.’
“I had watched Wuhan but I assumed we must have not been worried because we did nothing. We just watched. A pandemic was always at the top of our national risk register — always — but when it came we just slowly watched. We could have been Germany, but instead we were doomed by our incompetence, our hubris and our austerity.”
In the Far East the threat was being treated more seriously in the early weeks of February. Martin Hibberd, a professor of emerging infectious diseases at the London School of Hygiene and Tropical Medicine, was in a unique position to compare the UK’s response with Singapore, where he had advised in the past.
“Singapore realised, as soon as Wuhan reported it, that cases were going to turn up in Singapore. And so they prepared for that. I looked at the UK and I can see a different strategy and approach.
“The interesting thing for me is, I’ve worked with Singapore in 2003 and 2009 and basically they copied the UK pandemic preparedness plan. But the difference is they actually implemented it.”Working holiday
Towards the end of the second week of February, the prime minister was demob happy. After sacking five cabinet ministers and saying everyone “should be confident and calm” about Britain’s response to the virus, Johnson vacated Downing Street after the half-term recess began on February 13.
He headed to the country for a “working” holiday at Chevening with Symonds and would be out of the public eye for 12 days. His aides were thankful for the rest, as they had been working flat-out since the summer as the Brexit power struggle had played out.
The Sunday newspapers that weekend would not have made comfortable reading. The Sunday Times reported on a briefing from a risk specialist that said Public Health England would be overrun during a pandemic as it could test only 1,000 people a day.
Johnson may well have been distracted by matters in his personal life during his stay in the countryside. Aides were told to keep their briefing papers short and cut the number of memos in his red box if they wanted them to be read.
His family needed to be prepared for the announcement that Symonds, who turned 32 in March, was pregnant and that they had been secretly engaged for some time. Relations with his children had been fraught since his separation from his estranged wife Marina Wheeler and the rift had deepened when she received a cancer diagnosis last year.
The divorce also had to be finalised. Midway through the break it was announced in the High Court that the couple had reached a settlement, leaving Wheeler free to apply for divorce.
There were murmurings of frustration from some ministers and their aides at the time that Johnson was not taking more of a lead. But Johnson’s aides are understood to have felt relaxed: he was getting updates and they claim the scientists were saying everything was under control.400,000 deaths
By the time Johnson departed for the countryside, however, there was mounting unease among scientists about the exceptional nature of the threat. Sir Jeremy Farrar, an infectious disease specialist who is a key government adviser, made this clear in a recent BBC interview.
“I think from the early days in February, if not in late January, it was obvious this infection was going to be very serious and it was going to affect more than just the region of Asia,” he said. “I think it was very clear that this was going to be an unprecedented event.”
By February 21 the virus had already infected 76,000 people, had caused 2,300 deaths in China and was taking a foothold in Europe, with Italy recording 51 cases and two deaths the following day. Nonetheless Nervtag, one of the key government advisory committees, decided to keep the threat level at “moderate”.
Its members may well regret that decision with hindsight, and it was certainly not unanimous. John Edmunds, one of the country’s top infectious disease modellers from the London School of Hygiene and Tropical Medicine, was participating in the meeting by video link, but his technology failed him at the crucial moment.
Edmunds wanted the threat level to be increased to high but could not make his view known as the link was glitchy. He sent an email later making his view clear. “JE believes that the risk to the UK population [in the PHE risk assessment] should be high, as there is evidence of ongoing transmission in Korea, Japan and Singapore, as well as in China,” the meeting’s minutes state. But the decision had already been taken.
Peter Openshaw, professor of experimental medicine at Imperial College, was in America at the time of the meeting but would also have recommended increasing the threat to high. Three days earlier he had given an address to a seminar in which he estimated that 60% of the world’s population would probably become infected if no action was taken and 400,000 people would die in the UK.
By February 26 there were 13 known cases in the UK. That day — almost four weeks before a full lockdown would be announced — ministers were warned through another advisory committee that the country was facing a catastrophic loss of life unless drastic action was taken. Having been thwarted from sounding the alarm, Edmunds and his team presented their latest “worst scenario” predictions to the scientific pandemic influenza group on modelling (SPI-M), which directly advises the country’s scientific decision-makers in Sage.
It warned that 27 million people could be infected and 220,000 intensive care beds would be needed if no action were taken to reduce infection rates. The predicted death toll was 380,000. Edmunds’s colleague Nick Davies, who led the research, says the report emphasised the urgent need for a lockdown almost four weeks before it was imposed.
The team modelled the effects of a 12-week lockdown involving school and work closures, shielding the elderly, social distancing and self-isolation. It estimated this would delay the impact of the pandemic but there still might be 280,000 deaths over the year.Johnson returns
The previous night Johnson had returned to London for the Conservatives’ big fundraising ball, the Winter Party, at which one donor pledged £60,000 for the privilege of playing a game of tennis with him.
By this time the prime minister had missed five Cobra meetings on the preparations to combat the looming pandemic, which he left to be chaired by Hancock. Johnson was an easy target for the opposition when he returned to the Commons the following day: the Labour leader, Jeremy Corbyn, labelled him a “part-time” prime minister for his failure to lead on the virus crisis or visit the areas of the UK badly hit by floods.
By Friday February 28 the virus had taken root in the UK, with reported cases rising to 19, and the stock markets were plunging. It was finally time for Johnson to act. He summoned a TV reporter into Downing Street to say he was on top of the coronavirus crisis.
“The issue of coronavirus is something that is now the government’s top priority,” he said. “I have just had a meeting with the chief medical officer and secretary of state for health talking about the preparations that we need to make.”
It was finally announced that he would be attending a meeting of Cobra — after a weekend at Chequers with Symonds where the couple would publicly release news of the engagement and their baby.
On the Sunday there was a meeting between Sage committee members and officials from the Department of Health and the NHS that was a game-changer, according to a Whitehall source. The meeting was shown fresh modelling based on figures from Italy suggesting that 8% of infected people might need hospital treatment in a worst-case scenario. The previous estimate had been 4%-5%.
“The risk to the NHS had effectively doubled in an instant. It set alarm bells ringing across government,” said the Whitehall source. “I think that meeting focused minds. You realise it’s time to pull the trigger on the starting gun.”
Many NHS workers have been left without proper protection
At the Cobra meeting the next day, with Johnson in the chair, a full “battle plan” was finally signed off to contain, delay and mitigate the spread of the virus. This was on March 2 — five weeks after the first Cobra meeting on the virus.
The new push would have some positive benefits such as the creation of new Nightingale hospitals, which greatly increased the number of intensive care beds. But there was a further delay that month of nine days in introducing the lockdown as Johnson and his senior advisers debated what measures were required. Later the government would be left rudderless again after Johnson himself contracted the virus.
As the number of infections grew daily, some things were impossible to retrieve. There was a worldwide shortage of PPE, and the prime minister would have to personally ring manufacturers of ventilators and testing kits in a desperate effort to boost supplies.
The result was that the NHS and care home workers would be left without proper protection and insufficient numbers of tests to find out whether they had been infected. To date 50 doctors, nurses and NHS workers have died. More than 100,000 people have been confirmed as infected in Britain and 15,000 have died.
This weekend sources close to Hancock said that from late January he instituted a “prepare for the worst” approach to the virus, held daily meetings and started work on PPE supplies.
A Downing Street spokesman said: “Our response has ensured that the NHS has been given all the support it needs to ensure everyone requiring treatment has received it, as well as providing protection to businesses and reassurance to workers. The prime minister has been at the helm of the response to this, providing leadership during this hugely challenging period for the whole nation.”
Copyright, I assume, the Sunday Times, and reproduced here in flagrant disregard thereof.
google translation of the interim report, released on the 9th April. The full report not yet available.
Preliminary results and conclusions of the COVID-19 case cluster study (Gangelt municipality) Prof. Dr. Hendrik Streeck (Institute of Virology) Prof. Dr. Gunther Hartmann (Institute for Clinical Chemistry and Clinical Pharmacology, Spokesman for the Cluster of Excellence ImmunoSensation2) Prof. Dr. Martin Exner (Institute for Hygiene and Public Health) Prof. Dr. Matthias Schmid (Institute for Medical Biometry, Computer Science and Epidemiology) University Hospital Bonn, Bonn, April 9, 2020 Background: The municipality of Gangelt is one of the most affected places in Germany by COVID19 in Germany. The infection is believed to be due to a carnival session on February 15, 2020, as several people tested positive for SARSCoV2 after this session. The carnival session and the outbreak of the session are currently being examined in more detail. A representative sample was drawn from the community of Gangelt (12,529 inhabitants) in the Heinsberg district. The World Health Organization (WHO) recommends a protocol in which 100 to 300 households are sampled depending on the expected prevalence. This sample was coordinated with its representativeness with Prof. Manfred Güllner (Forsa). Aim: The aim of the study is to determine the level of the SARS-CoV2 infections (percentage of all infected) that have been undergoing and are still occurring in the Gangelt community. In addition, the status of the current SARS-CoV2 immunity is to be determined. Procedure: A form letter was sent to approximately 600 households. A total of around 1000 residents from around 400 households took part in the study. Questionnaires were collected, throat swabs were taken and blood was tested for the presence of antibodies (IgG, IgA). The interim results and conclusions of approx. 500 people are included in this first evaluation. Preliminary result: An existing immunity of approx. 14% (anti-SARS-CoV2 IgG positive, specificity of the method>, 99%) was determined. About 2% of the people had a current SARS-CoV-2 infection determined using the PCR method. The overall infection rate (current infection or already gone through) was approximately 15%. The mortality rate (case fatality rate) based on the total number of infected people in the community of Gangelt is approx. 0.37% with the preliminary data from this study. The lethality currently calculated by the Johns-Hopkins University in Germany is 1.98% and is 5 times higher. Mortality based on the total population in Gangelt is currently 0.15%. Preliminary conclusion: The 5-fold higher lethality calculated by Johns-Hopkins University compared to this study in Gangelt is explained by the different reference size of the infected. In Gangelt, this study includes all infected people in the sample, including those with asymptomatic and mild courses. The proportion of the population that has already developed immunity to SARS-CoV-2 is about 15%. This means that 15% of the population in Gangelt can no longer become infected with SARS-CoV-2, and the process has already been started until herd immunity is reached. This 15 percent share of the population reduces the speed (net reproduction number R in epidemiological models) of a further spread of SARS-CoV-2. By adhering to stringent hygiene measures, it can be expected that the virus concentration in the event of an infection in a person can be reduced to such an extent that the severity of the disease is reduced, while at the same time developing immunity. These favorable conditions do not exist in the event of an extraordinary outbreak event (superspreading event, e.g. carnival session, apres ski bar Ischgl). With hygienic measures, favorable effects with regard to all-cause mortality can also be expected. We therefore strongly recommend implementing the proposed four-phase strategy of the German Society for Hospital Hygiene (DGKH). This provides the following model: Phase 1: Social quarantine with the aim of containing and slowing down the pandemic and avoiding an overload of the critical care structures, especially the health care system Phase 2: Beginning withdrawal of the quarantine while ensuring hygienic framework conditions and behavior. Phase 3: Abolition of the quarantine while maintaining the hygienic framework Phase 4: State of public life as before the COVID-19 pandemic (status quo ante). (DGKH statement can be found here: https://www.krankenhaushygiene.de/ccUpload/upload/files/2020_03_31_DGKH_Einl adug_Lageeinschaetze.pdf) Note: These results are preliminary. The final results of the study are published