It is predicated on some dodgy assumptions — principally, that vaccinated individuals still transmit at the same rate as the unvaccinated, that ‘naturally immune’ individuals somehow by contrast do suppress transmission, and that the natural infection route does not select for mutants at the same (or higher) rate.
The biggest problem — and it’s a general one — is the first. I’m sick of seeing people claim that ‘the vaccine does not stop transmission’. It was never definitively demonstrated anyway, despite being widely circulated as categorical truth, and is a common misunderstanding of the scientifically cautious ‘we don’t know if …’. Well, we now have data. The vaccines have all been shown to substantially reduce transmission. If one wants to be a pedant, one could say ‘reduce’ doesn’t mean ‘stop’, but if fewer individuals shed viable virus in the vaccinated than unvaccinated group, it has clearly STOPped transmission in a greater number of individuals in that group. It’s not that it’s generated the same number of transmitting individuals but with lower levels per individual; there are fewer transmitting individuals. That matters. Those individuals are invisible to the virus. It has the same effect as reducing population density.
Much of what can be said about vaccine can also be said about ‘natural immunity’. Yet one never hears a parallel uncertainty over transmission from previously infected individuals. Well, as it happens, data shows that this too is reduced (or ‘stopped in more individuals’) for reinfection of the original strain. There’s the rub. There are worrying signs that the Brazil mutant can reinfect individuals. If reinfection is occurring, the Brazil mutant is not a ‘vaccine escape mutant’; it is a ‘natural immunity escape’. So the thing he’s worried about actually results from the strategy he advocates.
The key to reducing mutations is to reduce replications. You can create a selective pressure by doing that, but you also reduce the opportunity for mutations that can respond to it. The optimum would be to vaccinate (or infect) everyone in a day! That would knock it on the head for sure (at huge cost of life and health in the second case). Failing that, mass vaccination should proceed as fast as possible. It gives the opportunity of creating hundreds of thousands of ‘pseudo-infections’ per day without the health costs and, crucially, without the replications. It would be neither possible nor desirable to hit the same numbers ‘the natural way’. ‘Letting the disease rip’ creates a substantial excess of replications over vaccination, hence more opportunities for mutation and selection.
This is not really the way to do science: by non-peer-reviewed ‘open letter’, uncritically leapt upon by the vaccine-skeptic community with neither the knowledge base nor the appropriate scientific skepticism needed to evaluate his claims. I’m no expert, but I think his strategy would be disastrous.
I do not envy them, considering that the number, nature, and location of the mines are all in constant motion. I was involved in a multi-disciplinary study once looking at population trends in one city. There was some socialogical modeling of whether the population would grow (in hindsight, they guessed yes but in fact the population shrank), and if so, in what direction new development might take place. But the engineers wanted to know exactly where the future service stations would be built, so they could sample the soil!
This seems relevant to me, because I would dearly love to assess my own risk level. I’m fully vaccinated, but I live in the state with the lowest public vaccination level. If the UK is any predictor, the Delta variant may cause a spike in my immediate area. At one level, it’s not hard to predict that where vaccine penetration is lowest, transmission rates MIGHT be highest depending on who gets which variant (how much that person interacts with others, etc.) At the individual level, should I follow Fauci (“If you’re vaccinated, you’re safe”)? Or other experts saying I should perhaps be even more meticulous about masks, disinfectants, distancing, hand washing?
The problem I’m addressing is not whether the Chinese vaccines are totally ineffective, but whether the contribute meaningfully to ending the plague.
Things like the delta variant hint at the need to speed up immunization.
My personal prediction curse could be striking. Chile may just be starting a decline in cases and deaths.
But we are racing against the evolution clock. We need to do whatever is necessary to increase use of the best vaccines.
It’s okay to save lives with what is available, but we really need to end it.
Yes, it has real consequences. Lack of approval limits the ability of schools and employers to require vaccination. And gives ammunition to refuseniks.
My suspicions are the word of god. Yours are childish ramblings.
Is that the way science works?
Yes. I noted that a 95 percent vaccination rate with a 50 percent effective vaccine is approximately equivalent to a 50 percent vaccination rate with a 95 percent effective vaccine. Oddly enough, that reinforces my argument.
Now reach 60 or 75 percent immunity with the 50 percent vaccine.
My question is, which vaccines have the ability to end the pandemic with achievable vaccination rates.
If you merely slow the spread, you risk the evolution of a variant that eludes all the vaccines.
Pfizer is now being give to kids age 12-16. Within a couple of months it will be approved for younger children. That’s a huge pool of socially active people.
Why not just accept that we should be accelerating the use of things that work. That doesn’t preclude lesser products when there are no alternatives.
But I would argue that most nations will not like having to redo their vaccination campaigns, and I suspect they will have to.
That’s just FUD. Show me some numbers. Do a bag of marbles simulation.
I did not start thi by searching for some way to discredit Sinovac/Coronavac.
I started by looking at national vaccination rates at ourworldindata.org.
I was looking for evidence that the vaccines were working.
I found half a dozen countries that had vaccinated at least half their populations.
So I looked at their case and death rates. I was surprised to find several where the rates were not declining.
So I searched to find out what vaccines they were using. This is not easy, because most countries are not reporting this. But when I searched generically on the anomalous countries, I found articles stating they were unhappy with the results of their vaccination programs, and found that they had relied mostly on the Chinese vaccines.
I also discovered the difference in effectiveness rates. I didn’t immediately do any math. I just assumed that half as effective meant half the results.
Then I was attacked her for being ignorant and childish. Not attacked with peer reviewed articles or with numbers, but with bluster, personal insults, arguments from authority.
So I continued watching the results in Chile, and wondering why.
Eventually I did the mental bag of marbles simulation and realized the differences in vaccine effectiveness comports with the observed results in Chile and Bahrain.
If you want to convince me this isn’t the most likely explanation, walk us through an alternative scenario.
If you want to introduce magic variables, such as differential vaccination rates by social class, please provide data.
As the percentage of immune people increases, the chance of exposure declines. With no intervention, the virus dies out, eventually.
This increase is the combination of people recovered plus people effectively vaccinated.
Infection is relatively slow. It has taken a year for the world to have 200 million reported cases. That’s three percent of the world population. If we assume two thirds of infections are unreported, it means ten percent total infections. Roughly speaking.
It would take a long time for the world to achieve herd immunity.
In just a few months, 20 percent of the world has been vaccinated. Much faster. And safer.
The rate of immunity achieved through can easily swamp the rate achieve through infection and recovery. But appears that national percentages are not likely to go beyond 70 percent. France, for example, has thirty percent of its population saying they will refuse to be vaccinated. This varies widely among nations, by twenty percent is common. And children are mostly not being vaccinated.
So a thought experiment.
Assume thirty percent immune/recovered.
Now assume 50 percent vaccinated who are not redundantly immune.
If the vaccine is 95 percent effective, you achieve > 75 percent herd immunity.
If the vaccine is 50 percent effective, you get 55 percent.
To get to 75 percent, you need 90 percent non redundant vaccinations.
It’s a matter of speed and of achievability. How fast you get to your goal, and how possible, politically.
Show me a country or showcase region that doesn’t comport with this.
Furthermore, I can make a falsifiable prediction.
The same pattern will hold everywhere. The British and American vaccines will produce the same decline in cases and deaths with half the percentage vaccinated.
That is non-trivial, because they can control the pandemic with a vaccination rate that is achievable. It looks like 60 percent for Israel and UK. There is no percentage that is double 60. I don’t think any nation will achieve herd immunity without a significant percentage of the better vaccines.
I will make a personal prediction that within a few months, you will see people who got the less effective vaccines will want a Pfizer or Moderna booster. Already, I’ve seen recommendations like this for J&J recipients.
I’ll be a guinea pig. I’m fully vaccinated with Astra-Zeneca and am currently enjoying a very full social life. Why is US finding approval for AZ so problematic?
Didn’t bribe the right people?
I’d suggest a campaign donation.
petrushka,
🙂
Maybe not,
“In 2009, a strain of swine flu swapped genes with both human influenza and avian influenza to create a new variety of H1N1 flu that was “more like 1918 than had been seen in a long time,” says Taubenberger. Around 300,000 people died from the 2009 flu pandemic.
All told, if 50 to 100 million people died in the 1918 and 1919 pandemic, and tens of millions more have died in the ensuing century of seasonal flus and pandemic outbreaks, then all of those deaths can be attributed to the single and accidental emergence in humans of the very successful and stubborn 1918 virus.”
https://www.history.com/news/1918-flu-pandemic-never-ended
I don’t need to show you any numbers. I illustrated it perfectly well here, taking the extremes and showing that the ratios must change between those extremes, since they are demonstrably different at those extremes – infinity and 1 respectively.
Allan Miller,
I think it’s reasonable to ask where we are now, and what is the most productive use of resources.
If it is in fact impossible to obtain the more effective vaccines, then use what you have, I would agree. But I think politics and national pride are getting in the way of negotiating the best solution.
If the latest news from Israel pans out, we’re in for a bumpy ride.
To be continued.
petrushka,
UK is hardly doing brilliantly, despite earlier Brexity crowing regarding getting ahead of ‘the EU’ on vaccination. Also confounding many expectations, including my own, that the advance of summer would give us a respite. Part of the problem is that the new variant has a higher R0, so you have to chuck away your previous herd immunity threshold. Also, R0 is a bit of a blunt instrument, giving a false expectation due to the granularity of distributions in the real world when, as is often the case, it is simply averaged across a population heterogeneous wrt susceptibility/vaccine status, density, demographics etc.
I’ve never had much interest in R0. Seem like a postdiction. As people have pointed out, it’s not a constant.
I think covid will be around pretty much forever. At some point vaccination will be required for school and for air travel. Hopefully with something better than a fifty percent vaccine. But there will be pockets.
What I don’t understand is the lack of enthusiasm for the vaccines. We have deaths almost equivalent to a world war, but where’s the anti-covid movement? Where all the organizations that claim that lives matter? Where are the celebrities?The minority leaders? The media? The movie and TV makers?
petrushka,
The anti Vax movement is pernicious. Oddest are the people who are anti lockdown and anti Vax, despite it being the best way out of them at present. They see vaccination as some kind of ‘control’, though I’ve no idea how I’ve been controlled by the 2 jabs I’ve had, nor the many I’ve had in my life. They are hopelessly naive if they think governments would readily end both lockdowns and vaccination programmes in the face of high case numbers.
Another oddity is the attempt to persuade others. No-one is interfering with their personal right to choose. Why care what someone else does? There was a large demo in London yesterday – a bit anti-everything, but anti Vax were part of it. We have to have security and bag searches at the vaccination centre I volunteer at.
This for sure makes no sense at all. I suspect its a type of pressure to them, where they feel if everyone else gets it, they are outliers who are not going to be readily welcomed by a society that wants to move on from this virus. So they want more people on their team.
Allan Miller,
In the United States, the least vaccinated groups are blacks and hispanics. Shots are now unrestricted, and available without appointment at grocery stores.
I do find the chart showing opposition to vax interesting and surprising.
In all countries that report age statistics, the overwhelming percentage of older people have been vaccinated. Generally above 80 percent.
That might account for the continuing drop in deaths, despite pockets of rising cases.
Uraguy is another country using Sinovac predominantly, with numbers that look like Chile’s.
Sweden joins Israel in having a week of zero deaths. Their vaccination rate is mid pack compared to Europe.
petrushka,
Yeah, people say the same about fitness … 🙄
I’ve seen a lot of writing about R numbers, but I don’t see anything that nails it as a property of the virus itself. It’s a property of the virus in a population. It varies with the susceptibility of the population and with the behavior of the population.
The susceptibility varies as the percentage of immune people varies.
But the R number follows the same kind of curve as my efficacy calculation.
Reducing your exposure by half does not make you half as likely to be infected. It hardly even delays infection.
Anyway, my point is, the R number is pretty much another way of expressing changes in the rate of infection in a population. It looks like you can derive one from the other. At least, until you approach herd immunity.
But see my point above. Getting fifty percent of a population immune does not cut your chance of infection in half. That’s why the usual herd immunity number is said to be 75 percent. That’s what it takes to bring R down to less than one.
What you can’t derive directly from the rate curves is the percentage of a population that is immune. You get that from counting cases, estimating undocumented cases, and adding non redundant vaccinations.
Ultimately, the only thing that stops a pandemic is immunity.
Distancing and quarantine can slow the spread, but until you reach herd immunity, you can’t stop it.
Diseases like smallpox could be stopped without herd immunity, because people who were transmitting also had visible symptoms, and transmission required physical contact.
Covid can be transmitted by people having no symptoms, simply by breathing in the same space.
China may have contained the virus, but it hasn’t stopped it. Unless the population already has significant cross immunity from previous coronaviruses. They will be interesting to watch.
The pacific islands, including Australia, will be in lockdown until they are vaccinated. And that means with a vaccine that s more than 50 percent effective.
Actually, R0 is a property of the virus and how people are behaving; it assumes everyone is susceptible. Then R0 x {% susceptible} = Re. These two numbers are very useful, just like fitness.
Your phrasing is too vague to have any meaning.
And that ‘herd immunity number’ assumes that the R0 is less than 4. There is an exquisite interplay between the percentage immunity needed and the R0 number. And the R0 number depends on physical distancing and mask-wearing measures.
Well, actually, you get that from seroprevalence. Seroprevalence allows you to estimate undocumented cases, which is a lot better than the wet finger in the wind approach we had to rely on a year ago.
I think vaccination helped. A lot.
DNA_Jock,
Two separate things: people in developed nations were mostly vaccinated against smallpox, but there was a persistent reservoir in third world countries.
The strategy of immunizing everyone was not feasible.
The actual final push involved thousands of vaccinations rather than millions. This was possible because the transmitting people had visible symptoms.
Covid does not provide for much success by isolating people with symptoms.
My issue is not whether vaccines reduce cases, but whether they are sufficient to stop the pandemic in a desirable time.
My argument is that immunizing (as opposed to vaccinating) half the population does not cut cases and deaths in half. I don’t know what the magic percentage is, but I read that 75 percent is the hoped for herd immunity number.
My other argument is that changing behavior so that you eliminate fifty percent of exposures does not reduce cases or deaths by fifty percent. To get a dramatic reduction in cases, you need to cut exposures much, much more.
This becomes a political and economic problem.
China may have cut through the behavioral problem, but that only delays the spread. As long as there are reservoirs, the pandemic will return. I assume that is why China has a massive vaccination program.
My falsifiable prediction is that the less effective vaccines will fail to stop the pandemic unless supplemented by more effective vaccines. (Or lots of cases and recoveries.) Part two of my prediction is this will happen. It’s already policy in Bahrain and UAE.
In the meantime I offer the Seychelles and Chile as high vaccination countries that continue to have high death rates.
To be fair to China, they say they are working to improve their vaccine.
And the jury is out on whether Pfizer er al will require additional boosters.
Thank you for proffering an argument.
Your arguments are both wrong.
Reducing Re by two-fold (whether achieved via immunization or behavior) has a greater than two-fold effect on cases and deaths. But reducing Re by five-fold could easily have a hundred-fold effect on cases and deaths.
So a more effective vaccine is MUCH more effective than a mediocre one. However, a 50% effective vaccine is a LOT better than a poke in the eye with a sharp stick.
Try running the numbers with a virus of R0 = 4 (corresponding to your herd immunity at 75% immune rule of thumb).
No vaccine : pandemic ends after 75% infected
50% effective vaccine: pandemic ends after 25% infected
80% effective vaccine: pandemic ends “immediately”
Funny, I thought you had already noticed the decline in new cases in Chile.
Citing the Seychelles is some epic cherry-picking, though, I enjoyed that. 🙂
I’ve thought about my last post. I won’t retract it just because it’s embarrassing, but it is.