Low herd immunity numbers
The last couple of YouTube shows discussed numbers around 15% of population for heard immunity. I think this expected. In any population there will be a number of people who ignore safeguards thinking this is a conspiracy, thinking I’m young and fit so I don’t care, air heads etc; for want of a better term, let’s call them morons. So, I expect it is mostly these morons spreading the virus plus infecting their families, friends and workmates. You don’t need 70% of the population infected for heard immunity, you only need 70% of the morons which probably works out to be around 15% of the overall population.
Thanks for the great show Chris.
I am on board with you. I actually posted a comment on another thread really addressing this in sort of different terms and different analogy. But the principle is the same. Yes, right now we are seeing a decline in cases in countries that have chose to let it burn or not wear masks. And the outcomes look good. How? because of those who are doing the burn.. Your so called moron demographics.. yes the same group that brought the average case age from 64 down to 34 in florida when things opened back up. Yes these people have spread it among themselves very effectively and then to their families. but mostly they have thrown caution to the wind. Fortunately for most of them, it is not a big deal. meanwhile the more vulnerable people 40+ responsible, have jobs, families, etc.. have continued to take precautions.. and the 60+ have buried themselves in deep isolation.. the numbers substantiate this. so yes , a smallest part of the population, being the most social. the most mobile, the highest risk for transmission, are only about 15% of the population but could be easily as high as 50-60% of the spread.. I have concluded that the flu dies off during summer, not because of weather, but perhaps because school is out.. and we have that right now as well.. so really the only turners and burners are the 20 something crowd..
But your point is well taken.. I agree. The Super Spreaders are the 20 somethings.. accounting for up to 65% of the spread while accounting for only 15% of the population.. So yeah..
The latest data from India shows that over 50% of the inhabitants of the slums in Mumbai have Covid antibodies. Close contact, open sewers, often no running water, communal eateries and markets, and they have the desired mysterious “herd immunity.” I seriously doubt everyone there is mask compliant. BTW, they do not have numbers of people falling over on the street from the virus so somehow all the pundits are wrong yet again.
I do not know if these individuals have access to HCQ. That would seriously alter the stats.
Herd immunity is the concept that if enough people get antibodies, any infection will burn itself out as the non-antibody group is too small. I disagree with this premise, because pathogens, specifically viruses, notoriously mutate. Antibodies to one virus doesn’t ensure antibodies to another as is seen in the different strains of Ebola. There is one where I know it does confer to another- cowpox to smallpox per Jenner, varicella to smallpox per vaccine. But this too could be challenged as the immunity to smallpox via vaccine wanes over time, and it doesn’t account for new strains from tinkering with CRISPER etc.
Pathogens are a known risk factor of being human. We cannot outwit them. In the past, contagions like the Black Death and Justinian’s Plague were not caused by, but facilitated by environmental and social factors. Various solar events like out current Grand Solar Minimum and local weather changes cause effects on plants, animals, and humans. The mutations in grasshoppers to locust happening world-wide and release of anthrax spores from desert dust storms is proof of that. The horrendous flooding in southern China will not only have the immediate effects of lives lost and towns destroyed, but the age old dilemma of cholera from dead carcasses and sewer contamination of water sources. Farmland is now polluted with industrial waste and debris as well. Famine will follow. There’s no way to vaccinate our way out.
The one thing that is universally helpful to fight any pathogen is a strong immune system in the host. Clean water, nourishing foods, adequate sleep, exercise these are something we can control. “Keeping your wits when all around you lose theirs”…RK
Many good points.
As an engineer, I see a few caveats:
1. Herd immunity is a dynamic number that relies on R. R0 is R before any mitigation, and I am not even sure we know it with precision, mutations etc. So if herd immunity is achieved with measure such as social distancing in place – it may in fact not have been achieved in practice as population becomes more “frivolous”.
2. R0 will probably vary widely by location because say a farmer in Iowa or remote parts of Norway likely inherently practices social isolation at a base level and not exposed to say public transport and crowds. Also, say a group of farmers going to a convention in the city will not be protected to the same extent as the city dwellers who have burned to a higher level of infected. Indeed, they might also be at risk from each other even before arriving at the city because R increases when they change their behaviour (say travel by train to the city – “huddling together”).
3. Herd immunity is a theroretical concept that works well until you have movement of people – say import of cases even over shorter distances. This means there will likely be small fires on an ongoing basis and those at risk still need to take extra precautions, and city dwellers are only safe on a statistical population basis over time. The individual, not even in a risk group, is not safe unless already immune.
4. Indeed genetics may well play a role. Heterogenous societies have an extra layer of uncertainty. If the “social mixing” is inadequate, the risk of outbreaks – perhaps even significant will be present “forever” since level of immunity needs to be driven towards the high side for more isolated (or less base immune) groups.
5. Herd immunity if it were allowed to drive infections to zero would eradicate the disease. However, this is not going to happen since the world is a diverse place and people seem to desire to travel a lot. The only way to be protected at the individual level is to become immune somehow. Mankind is crafty so I expect this to be statistically possible (say 50% probability of immunity) relatively soon. Hopefully any solution is tested well.
I posted this on another thread earlier – the point being that populations appear to have some level of pre-existing T-cell based immunity;
2/ The pervasive misconception is that we have zero immunity against COVID-19. Based on this flawed understanding, epidemiologists projected that herd immunity is not reached until 60-70% are infected.
This is almost certainly wrong.
Of course, the media ignores this research
— James Todaro, MD (@JamesTodaroMD) August 10, 2020