Bill Gates' 400 million dollar bet - First Tuberculosis Vaccine in 100 years?

Just wanted to thank you and NickLaing for this exchange. I'm planning to use an adapted version of the thoughts/considerations as an example of estimating expected value in some resources I'm creating!

Working on a new, more effective TB vaccine: Cost per life saved?

• About 50% of phase 3 trials are successful. So 50% chance of the rollout being possible
• Being conservative on The Economist’s optimistic estimate of 10 million lives saved, let’s reduce it to [BLANK 1].
• So 0.5 (probability) x [BLANK 1] (lives saved) = [BLANK 2] lives saved in expectation.
• The trial is $550 million to open up this opportunity, then let’s estimate vaccine production and distribution costs $5 per person. 
• There are about 7 times as many TB cases as deaths, but the vaccine is maximum about 50% effective, and they’ll have to vaccinate way more people than currently actually get TB. So let’s guess that they need to vaccinate [BLANK 3] people to save the [BLANK 1] lives
• [BLANK 3] million x $5 = $[BLANK 4] in distribution costs.
• $0.55 billion (trial costs) + $[BLANK 4] (distribution costs) = $[BLANK 5]
• $[BLANK 5] (cost) / [BLANK 2] (lives saved in expectation) = $[BLANK 6] per life saved in expectation

Great comment thank you!

I would say this vaccine work could be far more cost-effective than the average spending on the global plan to end TB. Because of the nature of the disease (long follow up, long expensive treatment), TB costs so much money to treat and follow up compared with other diseases. Lets have a go at some Napkin calculations for potential vaccine cost-effectiveness?!

About 50% of phase 3 trials are successful, so that's easy to adjust for. So 50% chance of the rollout being possible

Being conservative on their optimistic estimate of 10 million lives saved, lets reduce that by 80% to 2 million. Each life saved could be equivalent to 20 DALYs averted, given TB kills a lot of older people as well. 

Remember here though we haven't included DALYs of those who were saved from suffering but wouldn't have died from TB so I think that makes this quite conservative. TB is unlike malaria in that because its a long and hard to cure disease suffering is a huge factor - I would imagine average suffering for the average person who doesn't die TB might well be over 1 DALY (it has probably been calculated somewhere)

So 0.5 (probability of trial success at current 50% prevention rate) x 20 (DALYs averted per life saved) x 2,000,000 (Lives saved) = 20,000,000 DALYs

20 million DALYS averted in the next 25 years (Not before 2030 mind you).

The trial is 550 million dollars to open up this opportunity, then I'm going to pretty randomly estimate vaccine ends up costing $5 per person (not sure how many doses are needed or production) to produce in the Indian factory like they have planned and distribute. If they vaccinate 500 million people that's estimated 2.5 billion in distribution costs. I could have massively over/underestimated the cost here. So 3 billion dollars all up, to prevent 20 million DALYs

$3,000,000,000 (cost) / 20,000,000 DALYs

That's an EV of about $150 a DALY, closer to GiveWell. And this might look much better value after suffering for non-deaths is factored in. 

Obviously this is a 10 minute calculation with ludicrous error and probably large mistakes, but I think its still useful to have a go!

Hi, Hakon,

We were very excited to learn of this trial, a much-needed step toward reducing deaths from tuberculosis. We applaud Gates and Wellcome for this sizable commitment of resources, which is, as Nick points out, necessary to gain adequate information about the vaccine's efficacy, but beyond the reach of most funders.

We have investigated TB-related funding opportunities, and we remain very open to funding either programs or research. However, we have several significant uncertainties about the programs we've explored so far and have not yet funded any at scale.

We are working on a report summarizing the evidence for mass TB screen-and-treat programs, which will provide more detail on our views specific to that type of program.

Best, Miranda

That's a great comment Eli - I'm not sure there is!

Probably the most shocking story of shelved innovations (not much talked about) is the discovery of the best malaria treatment we have in 1972, which took over 25 years to become the treatment of choice. A combination of China hiding the discovery and western mistrust, how many lives could have been saved if it had come into use 20 years earlier?

 https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4966551/

Thanks so much appreciate it, have made the edits!

Yes though, the dry cough was the thing preventing the collection of sputum.

Yep for sure - and with something like a 50% chance of success in phase 3 trials, the chance of it working are pretty good!

Those looking through an AMR lens could even argue that slowing down the proliferation of MDR/XDR TB could be the most important outcome from a vaccine like this - potentially more than direct lives saved through preventing the disease directly.

XDRTB has been an interesting one, obviously its a terrifying prospect, but it hasn't proliferated as much as I think we expected 10-15 years ago. When I did my tropical med diploma it was all the buzz, we feared it would spread from Russian prisons around the world within 10 years and leave millions with no options for treatment. Although it continues to spread, fortunately the proportion of patients with XDR hasn't increased as we thought it might, and in many cases has even reduced due to better treatment programs. 

For example here showed a massive reduction in Southern India https://www.nature.com/articles/s41598-020-74432-y

Saving someone a google search hopefully:
XDRTB = Extensively drug-resistant tuberculosis
MDRTB = Multi drug-resistant tuberculosis

Seems like it's my week of learning a bit about tuberculosis! What's up with the acronyms in the tuberculosis-space anyways? TB isn't that much shorter than tuberculosis.