Stockholm to reach herd immunity in May? | Hacker News Reader

Stockholm to reach herd immunity in May?

nrk.no

32 pointsjamesblonde81 comments

Swede here. There is lots of disinformation about the Swedish approach to the epidemic. Sweden is following the same basic strategy as other countries, which is to slow down the spread by mitigating actions so the health care system can cope and to protect people in risk groups. The primary difference in Sweden compared to outher countries are:

* Sweden decided early on that an evidence-based approach should be followed. Many policies that are implemented in other countries do not have a lot of evidence showing their effectiveness

* Policy is still primarily dictated by the experts at Folkhälsomyndigheten (where Anders Tegnell is from), and not by politicians. Most actions taken by the Swedish government has been pretexted by "as requested by FHM we have...". State epidemiologist Anders Tegnell is generally seen as "being in charge" of the actions taken, even though technically he has very little legal authority.

* Sweden has a very strong history of indepenent government bodies. In Sweden, there is specific legislation preventing government officials from intervening in specific cases if there is a government authority in charge of the issue. The legal term for this is "ministerstyre", "ministerial rule", and even if an action is not technically in violation of this legislation, it is often used if politicians try to intervene in cases without creating general legislation.

* Being a high-trust society some measures that have been implemented as strict laws in countries other than Sweden are instead communicated as recommendations with a very high compliance rate.

Can you expand upon the policies that have little evidence of effectivness that are being done by other countries. are Swedes also aware why the other countries are doing this?

Is it fear / politics / bad science etc?

I'm on mobile so can dig up links later. But one of the things I see mostly cited in foreign press is the decision to not shut down all schools.

Universities and what would be equivalent to high schools are doing distance learning, but lower grades are mostly open. The department of health has mostly cited two things for not closing lower grades.

1. Little evidence that younger people are the main vectors spreading the virus.

And 2. That if we shut down schools parents would need to stay home (and are encouraged to stay home via our social programs), and that would include a lot of healthcare workers placing our system under too much stress.

I think the most obvious examples are:

* Closing borders when we already have a pandemic in all countries. Swedish borders are still open.

* Closing schools when most evidence shows that it is not effective. Swedish schools are still open.

There is of course lots of debate about this in Sweden, some are worried that Sweden is not taking enough decisive action. There is however a wide-spread general support that the more measured approach in Sweden is a good one. Anders Tegnell has become a very popular public figure for his low-key bureaucratic but yet humoristic way of explaining the uncertainties involved and why Sweden is doing things this way.

I believe that the reasons these measures are taken in other countries is because it is a way to show strong political leadership in a time of crisis. I think this approach works less well in Sweden because people have very high trust in experts and (well-managed) authorities.

Aren't high schools and universities still closed in Sweden?

Edit: Run remotely, to be clear.

There is a strong recommendation that high schools and universities handle their education remotely.

This recommendation is followed. The Swedish government cannot order schools to be closed (a law was quickly put in place in the case that this be necessary. I'm not sure that it pertains to universities, though).

An interesting point regarding the "ministerial rule" is that the other Scandinavian countries don't have the same restriction on politicians, at least not in law/constitution.

This is an excellent example, the chief epidemiologist in Denmark had a clash with the Danish PM about this, because evidence does not support closing borders as an effective policy when we already have a pandemic. In Denmark, the measure was intruduced despite this, presumably because the government wanted to demonstrate forceful action. Sweden still has open borders (not that it makes much difference since most other countries have closed them :) ).

We have partially closed borders but still open to EU countries, Norway, Iceland, Switzerland, Lichtenstein and the UK.

I would add some pointers:

* Sweden doesn’t have anything equivalent to martial law.

* the government have in general very weak power to enforce rules that effect the population and all changes to current law must pass through their parliament. (This has though due to the current situation been relaxed in certain areas, a decision that went through the parliament).

> Sweden doesn’t have anything equivalent to martial law.

This may be true, but is there nothing resembling any emergency governance procedure, either?

No, apparently they had to construct a emergency procedure for this particular incident by going through and change the laws necessary to handle this pandemic. The whole opposition was in on those changes. Though most of it is to be able to circumvent laws like: they wanted to build a field hospital but to do that they need to have a permit which they didn’t have/get when they needed it. That delayed things. This is a just an example. Also these those changes have a time limit, but could be extended through parliament.

I'm sure most countries would like to think they are taking an evidence-based approach. A lot of the evidence is not very clear though, there are many unknowns. If you think you understand all the mechanisms, just listen to one of the prominent virologists. It's not any different to other areas: the more you learn, the more you realize how much you don't know. If anyone claims otherwise, they probably don't deserve your trust.

In such an environment, it's impossible for politicians to take decisions that are good in all aspects, but at least regarding health, assuming that's a priority, they can either err on the cautious or on the risky side.

Compared to most other countries, Sweden is clearly taking the latter approach.

That's not at all clear, and won't be clear for a long time. When it comes to optimizing long term public health there are more factors to consider than just coronavirus.

Some think that the Swedish state epidemiologist is confusing scientific approach and emergency management.

Children are typically main disease vectors in influenza epidemics. In Covid-19 they seem to be nonsymptomatic. It is not known yet if they are important vectors.

Two policy choices based on the information above:

(1) We don't close the schools until we have the information.

(2) We close the schools to buy time to find out. It's too late to act when the evidence comes in.

Taking the "evidence-based approach" in the case of Sweden has so far meant being late (in comparison to other countries) with every counter-measure. Yes, that might mean avoiding a counter-measure which would have been ineffective. But it also means having missed out on the positive effects of a counter-measure which - based on later evidence - proved effective.

I'd argue that the evidence-based approach is great when enough evidence is available. When that is not the case however - as with the new coronavirus - it certainly is imaginable that the evidence-based approach actually is a weakness, not a strength.

It’s really not about “evidence-based approach” per se, it’s more because of the notion of “expert authority”. The notion is that the government are heavily relying on the “expert authority” related to the current situation, in this case, FHM. This means that they follow what the experts are saying, which is by design not as mere information or guidance. This happens pretty much in any government body, like Swedish prison and probation services. The prime minister have very little to say about details of what they do (“minister rule”). The decisions are based on science rather than pure politics because they rely on that current government body for that. That does mean that they are late, which to I agree isn’t optimal but a trade off. The other reason is because the government have been slowed down due to the fact that they have to follow the current law. There’s no way for them to circumvent that as it is.

This has nothing to do with the government. FHM could have made suggestions/recommendations earlier than when they did it, when it comes to physical distancing, maximum group size, behavior in restaurants, public transport, care homes, or even the usage of masks in public (which still isn't even close to be encouraged). I've been following the situation in various countries, and it became strikingly evident how FHM was late with pretty much every single eventually recommended counter-measure - presumably because they didn't see evidence yet (or, alternative explanation: On purpose, as part of the high-risk herd immunity strategy, which does obviously require many people to get infected).

It's a beautiful thing that recommendations (instead of law enforcement on the streets threatening with fines) work good enough for large parts of the Swedish population. But then everything still comes down to the quality and effects of the recommendations.

There is evidence sufficient to make predictions, and evidence sufficient to prove something beyond doubt. When you say Sweden is taking a more "evidence based" approach, what you're really saying is that they're denying evidence of the first kind. What ever happened to the precautionary principle? Does Sweden still practice that in other areas, relative to the US (for example)? If so, then suddenly getting all conservative about what evidence to consider and calling the result "evidence based" is not only insulting to scientists and policy makers in other countries but a bit hypocritical as well. The arrogance astounds.

German here who moved to Sweden in 2006. Since January, state epidemiologist Anders Tegnell has constantly made claims which turned out to be inaccurate, misleading or at least overly optimistic. Among the more devastating ones is that he in an interview on February 8 stated that "there is absolutely no risk for coronavirus when traveling to skiing vacations in the Alps/Southern Europe". To me, such a lack of foresight as an epidemiologist alone disqualifies him from the heavy role he has. Therefore, I don't take any claim he makes seriously. Sadly, he loves media appearance and seems to be giving interviews all day long, every day. So it's totally impossible to escape those claims. They are everywhere.

Shockingly, his display of (partial?) incompetence has hardly impacted the credibility he enjoys among large parts of the Swedish society. In fact, many people totally love him. That's something I just cannot comprehend. To me, it looks like mass hypnosis.

My personal stance by now is that I'm not following the Swedish Health Agency's recommendations, but the German authorities', which I consider more trustworthy and competent (based on the absence of a track record of false predictions, a respect of cautionary principles, and an absence of exaggerated self-assurance). However, I don't like feeling that way. Usually I'm "emotionally" only reverting back to my native country when it comes to the Football World Cup :)

I think this is decidedly unfair critizism, and is based on cherrypicking statements out of context especially regarding timing. The statement about the Alps/Southern europe has for sure been shown to be false in retrospect, but when it was made nobody knew there was an outbreak brewing there, so it was very much based on what was known at the time. I don't think any epidemiologist could have predicted the big outbreak in the alps/northern Italy specifically, and as far as I know, the advise from Tegnell was not different from that of the German authorities at the time. Basing your judgement of Tegnell only on this statement seems very ill-advised.

"nobody knew there was an outbreak brewing there" How do you know that? It's 2020, a globalized world, heavy exchanges between China and Italy, supercomputers, complex models. Wouldn't one expect from experts in virology that they actually do have means to foresee these scenarios? I personally do. I was monitoring the coronavirus situation at that time due to personal travel plans. And by mid February I saw a high probability (70 % - 80 %) that we would have significant outbreaks in Europe. Thus, I do expect more from a state epidemiologist than such a display of false certainty.

Apart from that, Tegnell has been wrong in so many regards (how often hasn't he claimed that the outbreak is near a peak, or that there is reason for optimism??! I don't have enough fingers to count that). One would rather have to cherrypick in order to find a specific prediction/claim/statement which turned out to be correct.

In the end, it comes down to what we expect from our leading experts. The experts who in fact decide about many people's lives, in this case. Particularly in a country in which most people follow the state experts' recommendations without any questions asked.

What I expect from leading experts is to give clear opinions and recommendations based on their best assesment of the situation given available data. I also expect them to quickly and humbly adapt to new evidence when it is found, while keeping in mind that new is not always better.

I don't expect experts to always be right, sometimes the best prediction turns out to be incorrect. This does not change the fact that it was the best prediction at the time it was made, given the available data.

I personally feel that this is exactly what Tegnell is doing in public discourse, he is very quick to point out when there are uncertainties and what the nature of it is, but is still able to present clear advise. He has also demonstrated willingness to change when new evidence is found. This is a far cry from what I see many politicians are doing, and I think this is the reason he is enjoying very high trust from the Swedish general population.

Thank you, that’s insightful. An honest (not cynical) follow up question: Would that in consequence mean that in your perspective, an expert who in mid February somewhat speculative had pointed to a possible outbreak in Italy or elsewhere in Europe - based on predictive scenario modeling and probabilities - had done a worse job than one who ruled out such a possibility, by relying exclusively on that moment’s available data (despite virus data lagging a few weeks)?

> Among the more devastating ones is that he in an interview on February 8 stated that "there is absolutely no risk for coronavirus when traveling to skiing vacations in the Alps/Southern Europe".

To be fair, that sounds like he was just reiterating the World Health Organization's official and very vocal position on the covid19 epidemic, which nowadays has been patently clear that it was motivated by the Chinese regime's push their massive shameless Wuhan cover-up mess.

I'm very sorry to hear you are not following the recommendations of Swedish authorities, I would strongly recommend you do, because they are contrary to what you claim here, not actually based on Tegnells personal whims or vanity, but based on the many experts employed at the agency, and more importantly adapted to local circumstances in Sweden, such as the current stage of the epidemic, which areas are most affected and so on. As long as the German recommendations are stricter this is of course not that problematic, but it could mean you pay less attention to things that are more urgent to adress in Sweden.

They are stricter, that was the whole point why I mentioned it. So no need to worry :)

> based on the many experts employed at the agency

How can you make an appeal to authority while denying any non-Swedish authority? Are Swedish authorities just better then those anywhere else? Hm.

As a foreign national living in Sweden since 1978 I wholeheartedly agree with you. The Swedish authorities has been slow to react, fearful of disrupting business, generally been too lax, and has succeeded into turning this incompetence into a virtue, which large swathes of otherwise intelligent people are swallowing whole.

This incompetence, together with an health care organization for the elderly in complete disarray and shambles due to under funding and rampant privatizations is granting the elderly in Sweden a death rate far beyond any comparable country. It is a mess, and it is with a sense of disbelief one observes that the state epidemiologist is allowed to continue to be in charge.

There are explanations for the support however: since a lot of the criticism originally came from far-right quarters, it became a matter of political decency among all other parties to defend the state policy. In addition there is an effect that seems to take hold in crisis in almost all countries: support for perceived leaders will surge, and people will vehemently turn on any criticism. Pity the leaders in Sweden turned out to be so incompetent and that the valid criticisms have been drowned out completely.

Roughly million people live in Stockholm and 2.4 million people liven in Stockholm metropolitan area.

Assuming R0 = 2.5, you need (1-1/R0) = 60% of the population to be immune for herd immunity. That would be 600,000 in Stockholm, 1.4 million people in the metropolitan area, 6 million for Sweden.

Assuming the same infection fatality rate 0.002 as Finnish national health organization estimates: 1,200 deaths in Stockholm, 2,800 in the metropolitan area, 12,000 in Sweden. Currently there are just 1,400 total covid-19 deaths in Sweden.

Do you have any links/papers that explain the Finnish estimate?

> Do you have any links/papers that explain the Finnish estimate?

Unfortunately the Finnish National Institute for Health and Welfare doesn't have a culture of being open about these things.

The fatality rate depends on whether and how you can treat patients. The Finnish health care system has not yet reached capacity at this stage.

Neither has the Stockholm health care (ICU beds) reached capacity yet.

What's your point? My point was that you can't make that calculation with a current fatality rate.

Neither has the system in Stockholm, and in the rest of Sweden it barely ticks the mark.

For example in Skåne, a region with a population of 1.3 million currently 16 people are in ICU care from 6 days ago.

In Swedish: https://www.expressen.se/kvallsposten/sa-manga-ar-corona-smi...

Which fully supports the point I was making.

I like how you are using simple guesstimates to show how viable herd immunity is. Following on from this:

   600,000 people in Stockholm
   to be infected in, say, 120 days
   = 5000 new infections per day
   with, say, 1% hospitalisation
   = 50 new beds per day

This does not seem realistic to me.

50 new beds per day,

14 day average stay in hospital

50×14 = 700 extra beds.

I wouldn't place too much trust in the Finnish IFR estimate. Their IFR estimate a month ago was 0.05% - 0.1%. At the time there was no data to support that, and it turns out that they had simply taken their estimates from a ten year old pandemic preparedness plan, which was designed for an influenza pandemic.

It was basically the same mistake UK did. Now they have very slowly begun to adjust away from the misleading path they originally set on.

The Finnish national health organization has been subject to severe budget cuts for the past ten years. They are still saying that masks do more harm than good, and that it's absolutely impossible to stop the virus, despite South-Korea having done so for almost 50 days already.

Once you have a certain number of infected it would take a long time (months or years) to stop it without a vaccine.

Their updated estimate is similar to ones from Iceland (mass testing) and others. More people than expected go trough the disease without symptoms. At least 50%.

The math goes as follows:

- 60% need to be infected for herd immunity.

- At least 50% of infected show no symptoms.

- CFR is 0.7%.

0.6×0.5×0.007 = 0.002

(This math assumes that everyone without symptoms is a diagnosed case, so overestimte)

> It was basically the same mistake UK did. Now they have very slowly begun to adjust away from the misleading path they originally set on.

How so?

I don't see any adjustment.

The UK strategy was to not pull the trigger on lock down too early, and then to flatten the curve in a way that fills our front line health service's capacity without overstretching it.

All while increasing numbers of beds, ventilators and distributing PPE as widely as possible.

That's broadly what's happened.

What DIDN'T happen is... well... more or less anything proactively in February. But we're certainly not alone there.

In case of influenza, you only need innumity for 30% of the population.

But it isn't influenza.

And we don’t know whether we need 60% pop. Deadly diseases tend to have lower rates.

No, we don't know for sure, but the 60+% are the current estimate based on the data available. The rates are not so much dependant on how "deadly" a disease is, but on how long you don't know you have the disease before you get noticeably sick. And there Covid-19 is so nasty. As far as we know, one is infectious for some time before (if ever) you get sick. On the other side, those who do get sick, get so badly.

816 of the current 1400 deaths in Sweden have been in Stockholm. So based your math, we are at around 40% infection rate. I live here, and anecotely i can say that is too high. In my circles, maybe it's 10-20%. Lots of old folks homes were hit here that increase the IFR.

Reference:

https://experience.arcgis.com/experience/09f821667ce64bf7be6...

In the Netherlands with about 3.5k deaths on 17 M pop the estimation for infection rate is 3%, based on tests done on people giving blood. I'm not certain whether that 3% is an under- or overstatement (people giving blood usually more active than average, but also younger than the average inflicted and you won't go in when actively ill). It's a long stretch from a 3% to anywhere near herd protection though. The 40% infection rate for Sweden seems too high.

The 40% infection rate is an estimate for Stockholm, not for all of Sweden. The Stockholm region has less than a quarter of the Swedish population (2.3 million out of 10 million) but well over half of the covid-19 deaths (816 out of 1442). Stockholm is also the region with the lowest average age in the country, and the largest proportion of one-person households, so the fatality in the region might be skewed down.

My Norse isn't what it used to be but you're still looking at an 8x difference per capita with the Norwegian number following from a mathematical model and the Dutch number coming from inference based on blood measurements. I don't know what's true, but 40% with 816 deaths seems low. That's a mortality <0.1%.

Ask people more thoroughly. A lot of people in my circles have had vague symptoms like itchy throat or eyes, vague chest discomfort, general fatigue. I would say the 40% sounds about right.

It is estimated that at least 50% of the infected show no symptoms.

If you take that into account, it's seems my numbers are on the right ballpark again.

That herd immunity equation is really only useful in the context of vaccination when there's no active epidemic.

With an active scenario like this, it's just the point where the number of people infected per day stops going up. You still end up with like 90%+ of people getting sick before it finally peters out.

They haven’t even been hit that hard. Skipping the whole infection and death stage of this process doesn’t seem particularly realistic. People forget a key element of herd immunity: the immune ones are what’s left stand after the carnage

I’d expected the UK Spain and France to hit herd immunity first

> I’d expected the UK Spain and France to hit herd immunity first

Whoever has broad access to a vaccine first probably reaches herd immunity first. Natural herd immunity would take years to reach or massively overwhelm any health care system and kill millions.

Another important fact that is kept out of these discussions is that the whole point of social distancing and quarantines is to level the infection curve, so that health services aren't overwhelmed by epidemic cases and thus can remain functioning not only for covid19 patients but also any other type of medical care.

A disease can be killed off (or massively reduced) via herd immunity without requiring all individuals to have been infected.

> killed off (or massively reduced) via herd immunity

Natural herd immunity is the the end result of allowing infection to spread without limits.

Only with vaccine you can create herd immunity without getting infected. For the next 12-18 months the only way to get immunity is enough people getting infected.

Yes - at a cost of many unnecessary, horribly painful and lonely deaths.

Yes - via a vaccine. The 'measles' wikipedia page is a good primer on how effective natural herd immunity is (clue: it isn't)

> People forget a key element of herd immunity: the immune ones are what’s left stand after the carnage

Has it been concluded that people do actually retain longterm immunity? I was reading[1][2] previously that there isn't proof yet that immunity afterwards is retained for long. Seems still too early to tell.

ref:

[1]: https://abcnews.go.com/Health/questions-remain-covid-19-reco...

[2]: https://www.theguardian.com/world/2020/apr/17/coronavirus-fi...

one more: https://www.scmp.com/week-asia/health-environment/article/30...

No it has not.

The plan might face problems from time and economic perspective. Reaching herd immunity level might take way too long, even years, during which time most other countries are opening back up using mitigation strategies. Sweden meanwhile might be under travel restrictions imposed by other countries to ward off second wave, hindering their economy far longer than other countries.

It really does seem like a gamble, and I don't appreciate governments taking gambles.

Sweden is also using mitigation strategies, just slightly less than other countries.

To me, it seems that they started to use mitigation strategies because they figured the time/economic variable that I pointed out, and realized the impossibility of their gamble.

Compared to some of the southern countries (where three generations of a family regularly live together in one house), the Swedish population was already fairly distanced. See also https://www.politico.eu/article/social-distance-swedish-styl...

Herd immunity isn't going to work if reinfection is possible https://edition.cnn.com/2020/04/17/health/south-korea-corona.... Even if there's some protection (e.g. 6 months) it will be extremely difficult to maintain herd immunity.

Given that we don't know if either is possible as it's too early, what should we prepare for now?

It's a bit of precautionary principle, but the answer is not "plan nothing"

If reinfection is possible then vaccines are going to have a hell of a time.

He is not exactly saying or promising heard immunity in May but that they do have some mathematical models that point to that. He also states the caveat that these models are only as good as their input values and he doesn't sound confident about the correctness of those.

As much criticism as has been leveled at the approach in Sweden, you would think Sweden would be doing far worse than other countries. It appears actually to be doing better than average.

https://ourworldindata.org/grapher/new-covid-deaths-per-mill...

So, the approach appears no worse than what others are doing, and likely has fewer side effects.

Ok, so the interview is in Swedish (and Norwegian), but it is with Sweden's state epidemiologist at the Public Health Agency. He indicates that they have been taking antibody tests the last week as the basis for his prediction of flock immunity some time in May in the Stockholm region.

As far as I'm aware the antibody tests are really unreliable? At least the millions of tests the UK bought are not being used for that reason.

As I understand it, the quick antibody tests are the unreliable ones. For these tests, the blood will be collected at home and sent to labs where i would suppose reliable tests will be done.

Also, the tests will begin next week and the results will be published end of April or beginning of May.

In principle even if the tests are unreliable in individual cases, if the false positive and negative rates are known sufficiently well it ought to be possible to use mass results to get an accurate estimate of the prevalence of what they're supposed to be measuring.

He said they tested people for immunity (my interpretation was antibody tests, maybe i was not correct in the actual type of test - but they are testing for "immunity" (antibodies?), somehow).

Herd immunity implies herd infection. I am sure you are already aware of the mortality rates for infected citizens. All the best to this test. You are taking one for the global team. #forscience

Here are the issues with the herd immunity strategy:

- The R0 of this virus is higher than we once thought. The median R0 reported here is 5.7. https://wwwnc.cdc.gov/eid/article/26/7/20-0282_article - This means that some 80% of the population would need to be infected before reaching herd immunity - This also means the peak of infections would be far more concentrated. - Even with R=2.5, the number of hospitalisation necessary in an unmitigated peak would utterly overwhelm any health system - This overwhelming situation would mean a lot of people who otherwise would survive with medical treatment (oxygen etc) would end up dying

Preparing for the previous war is a classic mistake. This is irresponsible by Sweden without more data on the virus. New reports indicate that we don’t develop enough antibodies for herd immunity to be an option and it is even worrisome w/r to developing a vaccine. https://www.reuters.com/article/us-health-coronavirus-immuni...

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