Maybe a stupid question, but do we need to vaccinate everyone? I remember reading that heard immunity is 70% or something - so could we get away with leaving the people out that it wasn’t tested on?
THEORY: Assuming 100% efficacy vaccine. In completely homogeneous population if people are randomly vaccinated the threshold where the diseases effective R drops below 1.0 is 1 - 1/R. For example if R = 3.0 you need to vaccinate 66% population until infections start to decline.
REALITY: Assuming 75-90% efficacy vaccine, vaccination is non-random and population is heterogeneous. You want to vaccinate everyone who agrees to take it. Just like with children diseases, there will be clusters of anti-vaxxers, or people just don't bother and they are often clumped together, travel around the world and spread the disease.
It's not a stupid question, and I've heard that some vaccines are aiming to be approved only for adults at first. This would make sense not only because, as you say, you can start to approach herd immunity without vaccinating everyone, but also because children are weaker spreaders.
Obviously "herd immunity" is more of a gradient than a cut-off, and it's much easier to approach it if we can vaccinate everyone, but we can definitely speed up the process (including the months-long process to even get the vaccines to everyone) if we can start vaccinating some people early.
Theoretically the % of people needed to reach herd immunity is a function of how infectious the virus is. They use a number R to represent for each person who gets infected how many people they go on to infect. This changes over time as different measures come into place like lockdowns, masks, and social distancing. The basic reproductive number R0 (R-naught) is how infectious the virus is initially without any of those measures in place. The formula for the % of people needed to reach herd immunity is R0-1/R0. So if R0 is 4 then you need 3/4 of the population. If R0 is 3 then you need 2/3.
The vaccine may itself not be perfectly protective, and the herd immunity threshold only works if the people vaccinated are random. Otherwise any unvaccinated population can have an outbreak.
You should be able to see that Covid-19 is in fact a disease listed in the table on the wikipedia page you reference. You should also be able to see that the percentage required for herd immunity effect to begin (the 'herd immunity threshold') is a function of the R0 level for each disease.
In addition, to question of "can anyone really say for covid-19", I suppose the answer is 'No, but I would trust that the consensus of the scientific community of infectious disease experts is the best estimation we can get.'
i haven't read through all the questions asked here, but yours is perhaps the least stupid
i suspect you may already know the answer to your question; of course not everyone needs to be vaccinated - that's the job of any reasonably healthy immune system and this virus, which has not been properly isolated by the way, and that comes directly from the CDC, is not particularly dangerous, and that comes directly from the WHO
any thinking human being knows that masks are, at best, largely ineffective at preventing transmission, as is "social distancing" - the way governments are handling this "pandemic", which by definition is not a pandemic, is killing far more people and ruining far more lives that the virus ever will
the question then becomes, why? why are we being asked, and compelled in many case, to wear ineffective masks? why are being threatened and arrested in some cases for not distancing when there is no creditable scientific evidence to support that distancing works?
furthermore, the rt-PCR "test" that is used by many labs to diagnose COVID-19 is not a test - it is a procedure designed to amplify a tiny amount of RNA or DNA - it was never designed to test for this or any other virus and it does not produce a binary result, so in the end , we have NO idea how many cases there are, and it gets worse than that because apparently PCR is looking for any corona virus, alive or dead! that means that anyone that's ever had a cold can test positive (along with people that died in motorcycle accidents, fallen down stairs, or got shot in the face apparently)
the number of 'cases' is meaningless and the survival rate is exceedingly high, and if we make an adjustment for the radically inflated number of deaths, it becomes very questionable whether there even is a "novel" corona virus or whether it's the flu
lastly, even if one is not reasonably healthy, or just doesn't wish to spend a lot of time being sick, all that required is high-dose vitamin C along with D3 (and zinc wouldn't hurt) - what's a high dosage? 4 grams+ / hr. for an adult, not that it's critical because no one has ever died from vitamins (minerals is a different story)
> this "pandemic", which by definition is not a pandemic
> any thinking human being knows that masks are, at best, largely ineffective at preventing transmission, as is "social distancing"
> it becomes very questionable whether there even is a "novel" corona virus or whether it's the flu
You know, I live in Adelaide, where we haven't had a single locally-acquired case in several months. I've been wondering how almost every other city on the planet has been screwing things up so badly when we've not really done all that much apart from having a quick reaction and social distancing appropriately.
My question is now answered: those cities have people like you, willing to spout even the most blatantly abject conspiratorial nonsense for the sake of advertising your own website.
Please show some responsibility for the lives of those around you.
As someone living in Melbourne it's been frustrating to see this same nonsense spread locally by a very vocal minority, followed by "lockdowns don't work".
I'm celebrating that following the science here has taken us from > 700 new cases per day, to our second consecutive day of zero (and lockdown ending less than 3 hours from now)
