Yes, let’s vaccinate twice as many people against covid-19
I am very sympathetic to Robert Waldmann’s argument that we should give twice as many people one dose of the new Pfizer/Moderna vaccines, at least until supply constraints are eased, instead of following the FDA approved vaccination protocol and giving everyone two doses right from the beginning. What follows is a rough way of thinking about the logic and perhaps the magnitudes involved. Let me emphasize that this is just a finger exercise and I am not an epidemiologist, but with those important caveats I will share my work.
Here are my assumptions. The reproduction number of the virus is currently 1. This means that if behavior, transmissibility, and natural and vaccine acquired immunity are all unchanged, the number of people getting infected each day will remain the same. I assume that there are 300 million people in the United States, 40 million of whom are currently immune due to prior infection, and 260 of whom are susceptible. There are 400,000 new actual infections each day (two times the reported number of cases). These infections lead to 3,000 deaths per day (roughly the current number).
As the number of people with natural and acquired immunity increases, I assume that R decreases proportionately. Thus, with 400k new cases per day, in 100 days there will be 40 million more people with natural immunity, and R will drop from 1 today to 220/260 just due to individuals who recover from infections (without a vaccination campaign). I also assume that over the six months from January through June, 200 million doses will be distributed to either 100 million people (two doses each) or 200 million people (1 dose each), and that doses are administered at a constant rate over time. To keep the calculations simple, I assume that people with natural immunity are not vaccinated (hey wait, that includes me!). I assume that 95% of people who get two doses of the vaccine are immune (5% are vulnerable), and 85% of people who get one dose are immune. Finally, I assume that when a person becomes infected, they remain infected for one day, during which they pass the disease on to R other people and then either die or recover with natural immunity. (My guess is that this assumption is not harmless, it speeds up the adjustment times.)
So what happens in this simple model? First, the epidemic wanes rapidly in both cases. Almost all deaths occur in the first 60 days as natural and vaccine acquired immunity spreads rapidly in the population. This fast recovery could be an artifact of my timing assumptions, and it assumes no other behavioral or weather-related changes to R. In any event, the total deaths at 60 days are 65,000 with two doses person, and 53,000 with 1 dose per person, for a saving of 12,000 souls, plus many more severe illnesses averted. The absolute numbers seem somewhat optimistic (that is, low) to me (reflecting the fast waning of the epidemic in the model). The drop in total deaths seems plausible but presumably would be higher if the epidemic wanes more slowly than the model predicts, and especially if the epidemic explodes for a period in early 2021.
Because my model predicts the epidemic will wane quickly regardless of how doses are allocated, it does not suggest a large economic recovery benefit from giving 1 dose per person rather than 2. If (as seems reasonable) the epidemic drags on longer than my model suggests, doubling the number of people who are able to resume normal economic activity at each point in time could have large benefits for businesses, workers, and customers, and for public finances. We should also consider providing people with proof of vaccination and of prior infection (“immunity passports”) to make it easier for immune individuals to return to normal economic life.
I agree with Robert that it is unlikely that the federal government will lead the charge to double the number of individuals vaccinated. But the incoming Biden administration would do well to give this serious consideration (of course, this means doing more sophisticated analyses than I have done here). Yes, giving one dose per person will be controversial, but by April Biden will own the epidemic and it is far from clear Congress will step up with more economic relief. Doubling the number of people vaccinated might make the difference between a successful recovery and a presidency consumed with economic pain and political gridlock. This will be a clear test of Biden’s ability to act boldly rather than out of caution.
Eric you’re back. Damn it’s good to see you.
Bit off the cuff, but:
The Pfizer and Moderna have different times between the two shots; 4 weeks for Pfizer and 3 for Moderna, I think – something about lipid, transport, … Joel, can you help? Having worked within FDA regimes, gone through the changes in protocols, …, I suspect that there is a reason, and that it would be hard to get approval for any changes.
There is the possibility of a first batch becoming a one group’s second dose, which would get protection to more people sooner. I’m sure the goo General’s looking into it.
omit an a and d the good
We will have twice as many people out there — who are still afraid to participate in the economy or school or Thanksgiving dinner — will stay home. Better half as many who are back to work school. Two times nothing equals nothing — two times .5 equals one.
Only caveat: if evidence builds that if you get one shot you won’t die if you get infected — doubtful (true with two shots) and many of most might doubt it anyway, regardless of stats, meaning that would be no help to normalization.
@Ken,
When I got the shots as a subject in the Moderna Phase III trial last fall, they were spaced ca. 4 weeks apart.
Thanks, Joel.
It could well be the other way around. Probably from an interview that I watched. Quite a learning curve for all.
My apologies to all for the sloppy writing. See if can clear this up by stretching it out a bit:
I don’t know the exact procedure, but: Suppose that they are making/growing the vaccines in fermenters using mouse kidney, stem, … cells. The start up of a fermenter is the hard part. Once one is up and running, things usually go pretty smoothly. Once on line, cells are harvested as they reproduce; this may go on for several weeks. The harvested cells go through purification where the product is extracted. The spliced seed cells are key to the process; implying that a lot of bio-techs have the facilities for manufacturing the vaccines, if they used the same FDA approved protocols.
So, if they were to use the second half of the first lot that is intended for the second round for an intended group and use it, instead, as a first round for another group, they would double the number of people with some protection from the first lot. If there is surety of a ramp up, this could make a big difference. I’m sure the good General is thinking along these lines
@Ken,
I don’t believe either the Moderna or Pfizer vaccines require fermenters. You can synthesize massive quantities of homogeneous mRNA in vitro, and I think these are modified for increased stability. The viral-based vaccines (AstraZenica, J&& Janssen) would require fermenters, as will the protein vaccines coming online shortly.
“of course, this means doing more sophisticated analyses than I have done here).
. This will be a clear test of Biden’s ability to act boldly rather than out of caution.”
Without the results of the analyses how can you make that call?
Thanks, Joel. Been wondering.
EMike,
I don’t know anything about epidemiology and only a little about biology, but I know a great deal about using mathematical models to provide answers to real world problems.
Mathematical models cannot ever provide reliable point solutions to real world problems.
Mathematical models can provide useful boundaries for real world expectations by varying assumptions between best and worst case scenarios.
Mathematical models cannot reliably predict large scale results from small sample sets.
The randomness of samples is directly violated by any screening tests placed on samples that would not be equally applicable to the predicted result.
These rules are why election forecasters are glad that predicting election results is not a matter of life and death.
Those are the golden rules for mathematical modeling.
Ron:
Joel may be able to answer questions.
Realistically the protocol may be changed in due time, but more because of months of wider experience revising the risk management side along with warm weather reducing the risk of mass immunization under big tents instead of inside. That has been a no brainer from the start. In any case this is a one off requiring high expertise and responsibility. Joe Biden will do as advised, something Trump was incapable of, but I see that he is not alone.
This all strikes me as more than a bit academic since the real operational constraint doesn’t appear to be the availability of the vaccine itself, but rather the ability of doctors, nurses and pharmacists to get shots (or jabs…love that British term) into arms. To date we’ve only vaccinated about 1 million people with a first dose despite having many times that number of doses intended for initial shots just sitting in freezers. The goal was 20 million by the end of the year. We’re only about 5 percent there with Xmas Eve, Xmas, New Year’s Eve and one weekend left in the year. The bottleneck appears to be downstream of the wholesale warehouses. Maybe it’s a good thing that GEN Perna screwed-up and didn’t deliver as many as originally forecast.
@Ron and Run,
Mathematical models are as good as the data they are based upon. COVID-19 is new, so we lacked reliable data to predict the pandemic. Plus, human behavior is a huge variable. The Nobel laureate Michael Levitt predicted that there would be no more than 10 deaths from COVID-19 in Israel. As of this moment, the number stands at 3,171.
Predicting the effectiveness of the vaccines also depends on assumption built on limited data. One of the unknowns is to what extent a vaccinated person can still carry an infectious virus and infect others.
Joel,
Thanks, no surprise there.
Trump pulling our CDC staffers out of SE Asia that had been there for years precisely for the purpose of monitoring for contagious disease transmission was why we could not predict the pandemic. At this stage of the game medical experience and crisis management disciplines offer far better guidance than mathematical models, that from a guy who did mathematical models of large computer system performance for over three decades. In my field crisis management never entered in. I took interest in Ian Mitroff’s work for non-profressional reasons.
We just got up to have coffee. Then I fix an omelette stuffed with ham, cheddar, and bell pepper. Later I fix a roast turkey breast, not stuffed with butternut squash that I froze on Thanksgiving Day. Somewhere in there my wife and I will open our loot and then I have to gather up the trash. So, I will not have time to get into a further discussion today. I will Google up a link on the Trump fail and post it on this thread before I go.
Merry Christmas.
[There are just scores of articles bashing Trump on his handling of Covid-19, but this is my favorite smoking gun.] https://www.reuters.com/article/us-health-coronavirus-china-cdc-exclusiv/exclusive-u-s-slashed-cdc-staff-inside-china-prior-to-coronavirus-outbreak-idUSKBN21C3N5 March 25, 2020 6:26 PM
Updated 9 months agoExclusive: U.S. slashed CDC staff inside China prior to coronavirus outbreakBy Marisa Taylor WASHINGTON(Reuters) – The Trump administration cut staff by more than two-thirds at a key U.S. public health agency operating inside China, as part of a larger rollback of U.S.-funded health and science experts on the ground there leading up to the coronavirus outbreak, Reuters has learned. Most of the reductions were made at the Beijing office of the U.S. Centers for Disease Control and Prevention (CDC) and occurred over the past two years, according to public CDC documents viewed by Reuters and interviews with four people familiar with the drawdown.The Atlanta-based CDC, America’s preeminent disease fighting agency, provides public health assistance to nations around the world and works with them to help stop outbreaks of contagious diseases from spreading globally. It has worked in China for 30 years.The CDC’s China headcount has shrunk to around 14 staffers, down from approximately 47 people since President Donald Trump took office in January 2017, the documents show. The four people, who spoke on condition of anonymity, said the losses included epidemiologists and other health professionals.The material reviewed by Reuters shows a breakdown of how many American and local Chinese employees were assigned there. The documents are the CDC’s own descriptions of its headcount, which it posts online…
Apparently not all pastes taste the same :<)
[Peter Dorman over at Econospeak has his own criticisms of the vaccination program which was reposted at Naked Capitalism. His central argument is excerpted below plus links.]
…But there is another crucial question, to what extent do the vaccines reduce transmission of the virus to others? The answer does not affect whether these vaccines should be employed, but they do have large consequences for other policies during this phase of the pandemic, such as rules for separation and masking, restrictions on activities and events, resumption of in-person schooling, and how much should be spent on interventions like ventilation overhauls…
https://econospeak.blogspot.com/2020/12/rolling-out-vaccine.html
[The common thread here is that some people are stuck on the idea that now we have a Democratic Party administration then the screw-ups made by Donald Trump can be quickly reversed. A good rule of thumb is that generally it takes twice as long to unscrew the pooch and it took to screw pooch. In any case, the folk in charge of this thing have already told us that vaccination thus far is in the near term going to avoid losing all our healthcare workers to death or disability when we need them most along with protecting other critical workers and those most vulnerable and exposed to ending up in ICU. Masks and social distancing will be around well into summer if not until year end 2021. ]
Ron:
Peter posts his own words here at AB. I am assuming he just got around to it. 1st at Econo and then AB.
To deliver 200 million doses in a half of a year requires about 1.1 million shots per day. In the last 10 days we delivered about 1 million or about 100,000 shots per day. Can we ramp up the process ten times as fast in the next week? Not realistic to me.
just a thought: you give two shots to a large population, get 95% immunity, and the remaining 5% get “herd immunity.”
you give one shot to a larger population and get 85% immunity but no herd immunity.
(or)
some identifiable populations are at more risk than others. factor in efffective immunity from reasonable social distancing.
i think…no chance of my doing the math, or believing in it for reason Ron gives above…that it might work out better to give two shots to exposed populations (health care workers), and people who can’t hide…prisoners, nursing home residents… and tell the less at risk to behave themselves for a while.