The immune system works that way that even single digit amount of antibodies can start a chain reaction very quickly.
I don't think it's possible to say a yes or no answer if somebody has immunity using a lab test today.
Though, the vaccine is only needed to last long enough to eradicate the virus. If mass application of vaccine can plunge the r-factor well below 1, it should be more than ok if its protection only lasts 3-4 months.
Hypothetically speaking if you were a front-line worker exposed to the public and the vaccine only worked reliably for 90 days wouldn't you get it quarterly? It seems like the prudent approach to get r0 well below until we can drain the reservoir of disease because as others have noted, getting enough vaccines deployed simultaneously globally could be a challenge.
If it's really down to a single company not being able to manufacture enough then it's time to open up the vaccine to licensing and let other companies pile in.
> If it's really down to a single company not being able to manufacture enough then it's time to open up the vaccine to licensing and let other companies pile in.
The world is facing a few problems like this, where the structures of the economy are getting in the way of doing real work. Climate change is another one. If cost wasn't an issue, and everyone was paid by some infinite coffer, we'd have switched to green energy years ago and it wouldn't have been controversial at all. Only now that it's cost effective are we switching en masse to green energy, and we're having to drag economies kicking and screaming away from coal even still.
The community seems to be second to capitalism at every turn, and whilst I know it's not a new thought, it's becoming more and more prevalent that we've made societies devoid of the capacity for community effort.
Edit: Thought I'd clarify, my point is that our governments are meant to supply the community capacity through paying for work with our taxes, but often structures that benefit private businesses win out.
More specifically, you're hopeful that the company manufacturing the vaccine would actually open up to licensing, but they don't have to, and the US has consistently shown it's disdain for compulsory licensing. It would be an exception for them to force the company to license a vaccine, and it's not like pharmaceutical companies have an ethical track record in the US. If it came down to money vs community health, I would absolutely expect money to win out in the US. It already does. Worse yet, the US has bullied other countries into tightening their own compulsory licensing laws, in order to protect US pharmaceutical companies.
A friend in an ED just told me that 90% of her colleagues tested positive for antibodies but many of those worked the entire time and didn’t have symptoms.
There have been a few recent studies of cruise ships and meat packing plants with universal masking. In those cases an extremely high proportion of cases were asymptomatic.
To be clear, higher than in other cruise ships and other meat packing plants.
That’s the possibility, that lower viral load led to milder outcomes.
There was also a swiss military study where one group only got infected after distancing implemented. Positive cases, but no symptoms. Earlier group’s cases had symptoms.
How long does it take to vaccinate the entire world?
If the each contaminated person transmits it to two other people, you'll need to keep half of the people immune to each at any single time. If you are doing this by vaccines, you'll need to give it to half of the people on that immunity window.
At a billion doses per year it’s still 8 years to manufacture the vaccine for everyone. That’s assuming no supply chain issues. Moderna needs 2 doses which means only 500M protected per year which pages it to 16 years. I think the Oxford vaccine needs only 1 doses but because it uses a weakened virus there’s a chance a person develops covid-19.
Then you need to administer something like 300 doses per second globally, if you have 1B doses.
This is also assuming the virus doesn’t mutate during that time (it mutates very slowly but it could still happen).
The vaccine really needs to give multi-year protection otherwise it won’t be viable in the long run.
To be honest, there is probably a power law graph in play here when it comes to how many people are infective and infect others. If we can vaccinate / prevent spread in the demographics that are prone to mixing a lot / threaten spread, we can quickly curb it and then focus on people who are less likely to contract it / spread it around.
It feels like some of the demographics most likely to spread have overlap with groups unlikely to accept vaccinations.
Source: Live in Lansing MI where the nutty politicization of this issue is out of hand and there are redneck “anti-mask” protests seemingly once a month.
This is certainly the case. I don't have a link, but one study suggested 80% of cases were from "super-spreading" events, with one person infecting many others.
It doesn't actually use covid-19 virus so i doubt there's a chance of developing the disease from the vaccine. maybe it will have other side effects but covid-19 won't be one of them.
What would it take to ramp that up? The flu shot only lasts a year (for entirely different reasons, but still!), and in that case, we actually need to adapt the drug itself each season.
Moderna's vaccine does not require two doses, they administered two doses as part of their phase 2 trials to test for adverse reactions. They are only doing a single 100 µg dose for their phase 3 trials, and it's likely that will be the dose in the final vaccine:
Moderna has plans to be able to manufacturer 1 billion doses a year. AstraZeneca has announced plans to manufacturer 2 billion doses a year, with plans to produce 300 million doses by the end of 2020. The Chinese firms Sinopharm and Sinovac are ramping up their production right now, and will produce 200-300 million doses by the end of 2020. With all the other firms developing a vaccine it seems highly likely we could produce enough vaccine to vaccinate the entire population of the Earth in a single year. Now distributing and administering that much vaccine is another story, but manufacturing will not likely be the bottle neck.
I agree with your overall point that to put the fire out, you've got to extinguish all the embers.
But, as an alternative to synchronization, you could also require vaccinations for everyone who travels.
If a country gets it under control within its borders, it could require visitors to show proof they either (1) have tested positive for the disease and then recovered or (2) have been vaccinated recently enough (but not too recently) and also tested negative for the disease.
That way, you'd know they do not have it and have some degree of protection against picking it up while traveling to your country.
The unfortunate side effect if this became standard is that there may be far less motivation for wealthier nations to help poorer nations vaccinate everybody.
I don't entirely disagree that it might remove some motivation. But right now the whole world is in crisis, and I don't think gaining leverage by tying everyone's fates together is the best solution.
Anyway, the travel restrictions I mentioned would hardly be bulletproof. Vaccinations don't confer 100% immunity, and tests aren't 100% accurate. So countries could still reduce their risk by supporting worldwide vaccination.
Also, this might be a moot question if we can't produce enough vaccines to do it all at once.
If the immunity lasts for 4 months, we are talking about yearly vaccinating 200% of the population.
It's not impossible for countries with a small population, but AFAIK the flu is the largest scale vaccination in the world, and we are talking about something 4 times larger (than those countries that vaccinate the most - how are China and India numbers?).
But then, this seems to be the worst case with a reasonable likelihood. Things will probably be better.
I think we will be more limited by supply rather than willingness. Locking down for months has much more economic impact than one shot for each citizen even for poor country.
I don't think so; you couple a short term vaccine with testing and tracing so that you use it to break transmissions locally. If this was (god forbid) something with the transmissability of Measels then that would be useless.
In epidemiology, we determine "heard immunity" by calculating the proportion of the population that is in the Recovered (R) compartment (either through natural or artificial means). If your proportion that is in R is greater than 1-(1/R0) the incidence of the disease will start to decline.
Thankfully the R0 of SARS-COV-2 seem to be around 1.4–2.5 (meaning you need ~30% to ~60% recovered), so a vaccine would be actually very effective. I highly suspect "Travel to Europe" (i.e. international travel) may still be delayed for a long bit until we've gotten around to ~50-60% immunized, but it's tough to say.
Interesting, I wonder if when we're developing the vaccine, ability to easily mass produce the vaccine is a factor... I imagine the biggest issue once we have a vaccine is going to be how to get it out to everyone quickly enough... like I can see critical care workers and then maybe elderly and it being this really long time before it can be available to everyone... or do you start mass production of the vaccine and avoid distribution until you have enough to get everyone vaccinated so that you have the protection period of 3-4 months? Interesting to think it's not just the science of the vaccine but also the application of the vaccine that can be a factor... In the meantime it's promising that we're also learning how to treat the infection better and better...
Recently talking with my dad about all the situation and the vaccines, he brought up a case he studied when doing an MBA in the 90's: a vaccine where they used rats as bio-reactors. In tests and trials the vaccine was great, but it was so hard to produce and care for thousands of rats during the incubation period that in the end it wasn't economically viable.
He vaguely remembers the case as something from the 50's or the 60's and todya we have better technology all around. But yes, I understand that most labs working on vaccines do take into account the potential difficulties in production.
The economics will be different (more interesting/tempting) indeed. The point of the anecdote was that vaccine fabrication has been understood for a long time in the context of the scale it's required (again, the case was from the 50s-60s). I don't think any of the "promising vaccines" that are being tested now would fall in the trap of such a production scaling problem. Labs know this will be demanded in the billions.
That will be a really interesting question for the modellers, because vaccinating those who pose the highest danger of spreading the disease might have a much greater impact. If side effects turn out big you might even end up wanting to vaccinate everybody but the elderly.
Yeah, this is one big thing that's pulling the delivery times closer vs historical timelines.
Governments essentially said "If you can demonstrate reasonable efficacy and safety, go ahead and start mass production. If your Phase III trials fail, we'll make you whole and dump the doses in a landfill."
Otherwise, you had to wait the entire Phase III duration before even starting production, whereas now you'll essentially have viable vaccine on Day 0 when the Phase III trail concludes.
Not to belabor the point, but "r-factor" isn't the correct term here. If we're using a SIR model that assumes patients go from Susceptible (S) to Infected (I) and Recovered (R), we can still assume some proportion of patients can move back to the (S) compartment (i.e. losing immunity, what that is in reality for COVID obviously has a debate that I will not address here).
The "r-factor" (also called R_0, or attack rate), described the rate at which people once exposed to the virus move from S->I. The proportion of patients in (R) should not fundamentally change the r-factor.
That said, I do think your fundamental assessment in that moving more people from (S) directly to (R) would decrease the rate at which the disease spreads.
I think you're right. That said, I do wish that people would be a bit more precise (and focus less on generic and confusing jargon) in their language however when discussing epidemiology.
If you're lowing the number of additional people an infected person infects with a disease, that's measured by a lower basic reproduction number (Rx), which was what the poster above was talking about.
It being artificially reduction is kind of given as it a vaccine, but as the basic reproduction number is being used to measure the number of reproductions from each [known] infected person within population groups it seems like THE measure of a vaccine's impact.
You seem to be talking about something else entirely.
Given the USA's total failure at the presumably easier task of wide-scale testing, the notion that we could manufacture and distribute a novel vaccine in this time frame seems completely impossible. Maybe other countries could have success.
How much of that failure was manufacturing capacity, vs. bureaucracy? IIRC there was a California lab doing some testing that was shut down by the CDC... so manufacturing wasn't the bottleneck (maybe it's now? I don't know)
The federal government has already sent billions to vaccine manufacturers to get the ball rolling. It's named "Operation Warp Speed" and the goal is to have 300 million doses of a vaccine by January.
I don't think it's possible to say a yes or no answer if somebody has immunity using a lab test today.
Though, the vaccine is only needed to last long enough to eradicate the virus. If mass application of vaccine can plunge the r-factor well below 1, it should be more than ok if its protection only lasts 3-4 months.