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We are all waiting on some combination of a vaccine or effective treatment for #covid_19. Today's thread focuses on vaccines. 1/n
Vaccine development is said to take years. The question is why, and what in that process might be sped up, given the stakes for this vaccine. 2/n
There are 7 stages to vaccine development:
1. Research
2. Lab testing
3. Phase 1 study -- small, human subjects, safety
4. Phase 2 -- larger, safety and immunology
5. Phase 3 -- larger, effectiveness, double-blind, placebos
6. Production
7. Distribution 3/n
1. Research
2. Lab testing
3. Phase 1 study -- small, human subjects, safety
4. Phase 2 -- larger, safety and immunology
5. Phase 3 -- larger, effectiveness, double-blind, placebos
6. Production
7. Distribution 3/n
Where are we now?
One vaccine is in a Phase 1 study in Seattle.
https://www.nih.gov/news-events/news-releases/nih-clinical-trial-investigational-vaccine-covid-19-begins
4/n
One vaccine is in a Phase 1 study in Seattle.
https://www.nih.gov/news-events/news-releases/nih-clinical-trial-investigational-vaccine-covid-19-begins
4/n
Another vaccine has recently been tested in lab studies with animal subjects.
https://www.upmc.com/media/news/040220-falo-gambotto-sars-cov2-vaccine
5/n
https://www.upmc.com/media/news/040220-falo-gambotto-sars-cov2-vaccine
5/n
These efforts are already farther along than typical, for several reasons.
6/n
6/n
Normally, financial incentives for vaccine research are weak: research costs are high and future demand is risky
because many viruses kill so fast they die out on their own, while others mututate rapidly, making vaccines have short useful lives.
https://www.medrxiv.org/content/10.1101/2020.03.20.20039966v1.full.pdf
7/n
because many viruses kill so fast they die out on their own, while others mututate rapidly, making vaccines have short useful lives.
https://www.medrxiv.org/content/10.1101/2020.03.20.20039966v1.full.pdf
7/n
But for cov-19, the virus is apparently relatively stable (although there are numerous strains that have mutated over the past year), and the combination of a high reproduction (R) number and a modest but real mortality rate give it the punch it has had.
8/n
8/n
In addition, China decoded and published cov-19's genomic sequence for cov-19 in January, which was subsequently replicated from other carriers by researchers elsewhere.
https://www.sciencedaily.com/releases/2020/01/200131114748.htm
9/n
https://www.sciencedaily.com/releases/2020/01/200131114748.htm
9/n
Having the genomic sequence speeds up research on a vaccine.
10/n
10/n
As a result, some experts think the timetable for a vaccine for cov-19 will be "only" 18 months, rather than the more typical 5-10 years.
11/n https://www.healthline.com/health-news/covid-19-vaccine-more-than-one-year-before-available#Developing-a-vaccine
11/n https://www.healthline.com/health-news/covid-19-vaccine-more-than-one-year-before-available#Developing-a-vaccine
So why it still going to take more than a year?
Recall that research and lab testing are only the beginning of the process, and they are the only ones that can be dramatically reduced by investment and genomics.
12/n
Recall that research and lab testing are only the beginning of the process, and they are the only ones that can be dramatically reduced by investment and genomics.
12/n
The other steps involve human testing.
Two rounds of safety-focused testing are considered essential to determine whether a vaccine will cause more harm than good. 13/n
Two rounds of safety-focused testing are considered essential to determine whether a vaccine will cause more harm than good. 13/n
Those have to take place before it is safe to do truly large-scale randomized double-blind testing for relative effectiveness. Large-scale testing of a vaccine by definition puts large numbers of humans at risk. Hence the need for two prior smaller studies for safety. 14/n
Still, one might fairly ask whether in an environment in which 1000s are dying every day, whether the usual path for testing might be truncated or shortened in some way. 15/n
For example, perhaps Phase 1 and Phase 2 testing could be combined. 16/n
Perhaps the Phase 3 trials (which are focused on effectiveness) need not be completely done before vaccines could be deployed, but run in parallel to non-double-blind use of the vaccine on key at-risk populations. 17/n
To know whether these kinds of suggestions are worth considering or doing, an honest and transparent dialogue about costs and benefits and risks of the standard approach and alternatives would need to occur. 18/n
Now politics enters the picture: while the above possibilities are (to me, someone without medical training of any kind) plausible, what I do know something about (law, politics, incentives) suggests that they may not happen. 19/n
Even if a vaccine's being completed faster -- say by six months -- would be of enormous benefit to the world -- those benefits would not be felt (much) by the small number of people in a position to deviate from normal practice. 20/n
The FDA folks who oversee vaccine development in the US will be inclined, for both good reasons and less good ones, to stick to the standard practices. Deviations that create harm will be blamed on them; deviations that produce benefit will not much benefit them. 21/n
Same with politicians with authority over the FDA officials. Trump couldn't bring himself to honestly acknowledge cov-19 was a problem until the end of March. China, too, has almost certainly suppressed information about incidence and mortality in Wuhan. 22/n
Finally, what about the last steps -- often forgotten in discussions -- production and distribution? Those take real money, too. And private providers will not step in unless the government clearly and irrevocably promises a real return on investment. 24/n
I wish I had a happy tweet to end with, but I don't. /end
The public - understandably distrustful and suspicious of corporate welfare and corruption - will also deter politicians from embracing the kind of incentives that will get private companies to step in to produce and distribute a vaccine on a faster than typical timetable. 25/n
