Wait, since when has 2,000 not been enough? Everything I've ever learned about statistics tells me that proper sample sizes are not actually proportional to the total population in question.
It doesn't need to be proportional to the POPULATION. It does need to be proportional to the OTHER STATISTICS of the opposite risks.
Population could be anything. That's not why I'm saying you need millions of subjects. The U.S. could have 7 people in it or 70 trillion people, and you would still need the same millions of research participants.
The thing that is constraining it is not how many people live here -- what's constraining is the rarity of measles vaccine benefits at a given level of vaccination coverage.
There is no magical number of people that's just sufficient for anything. It totally depends what you're asking. Some areas of science literally use ONE participant (like low level retinal level response tasks where nearly everybody has identical biology). I've seen papers published with one participant.
Other things need 30 or 2,000 or 300,000,000 participants, depending on what you want to demonstrate, and how tiny the effects are.
Clinical trials for a heart surgery technique where you're 50% likely to die without it only need like 10 subjects to show sufficient safety.
Clinical trials for a seizure drug where you're 5% likely to die without it might need, I dunno, a couple hundred subjects.
Clinical trials for verifying the safety of a higher than 90% vaccination rate for a vaccine for a disease where you're 1/60,000,000 likely to die from it at 90% coverage, you need 300,000,000 subjects.
It is the size of the effects youre dealing with that determines necessary subject populations. Going from 90% vaccination to 100% has tiny tiny tiny even potential benefits, so you need to run HUGE numbers of additional subjects to verify that it's safe to move from 90% to 100% vaccination.
Going from 70% to 90% (as you'll see further down in this post) has larger potential benefits, so you still need to run more subjects to know if it's safe (than what we have now), but you would need to run fewer than you do to verify that 90->100% is safe.
He is talking on a "Well America doesn't have issues with Measles thus immunization is less important"
Sigh, no. No no no.
Immunization is
hugely important, and like I've said many times now, it is almost guaranteed that some vaccination is necessary to save the optimum number of lives.
But "vaccination" is not an ALL or NOTHING thing. There is some optimum rate, and it MIGHT NOT be 0% or 100%. It might be somewhere in between. In fact, it almost definitely is in between.
And whatever that optimal level is, it is going to be the optimal level everywhere in the entire world that has similar healthcare facilities as us. I.e. All of Europe, etc. And hitting that optimal level will be
equally important everywhere (including Italy). Any higher than the optimal level = unnecessary deaths. Any LOWER = unnecessary deaths.
Italy doesn't really tell us that much, but it is another datapoint. In Campania (one of the provinces), the measles vaccine coverage rate is about 70%. They had about 5 million people at the time of the data I have available, and they had ~3-4 deaths from measles a year. This is roughly 20,000 cases of measles, and about a 1/5,000-7,000 death rate (by the way, looks like I was right about modern medicine making it much less deadly than before, that's 1/4 the death rate of the 1960s)
So 1/1,250,000 people a year die of measles, or at that rate, over a lifetime, 1/16,000.
In order to show that MORE THAN 70% vaccination would be good for them, you'd have to show that the vaccine has a less than a 1/16,000 death rate. Which we don't have enough data to know.It is mathematically impossible with clinical trials that only run 2,000 subjects (or 5,000 or 10,000 or whatever we have total). Simple as that. To prove this rate of death or lower, you'd have to run about
75,000 subjects statistically.
However, notice that the amount of data needed to prove that (if it's true) is way the hell lower than the amount needed to prove that a 90% rate is helpful. This has nothing to do with Campania having a lower population. It has everything to do with the higher potential and known benefits of increased vaccination from a 70% level. Thus, vaccine safety doesn't have to be
AS stingently tested to justify vaccinating more than 70%. Though still more stringently than what we have tested so far.
As you go lower and observe higher death rates, the ability to gather enough data to say for sure is easier. Give me a place in Europe or somewhere else with good healthcare facilities with a rate lower than 70% and we might learn more. Does anybody know of one?
If I can get more datapoints, I can tell you exactly how much vaccination rate our current level of data verifies as lower than optimal. My gut instinct from these two datapoints is maybe 50%, but can't verify without actual more examples.