[AR] Re: ... Coronavirus
- From: Henry Spencer <hspencer@xxxxxxxxxxxxx>
- To: Arocket List <arocket@xxxxxxxxxxxxx>
- Date: Sat, 21 Mar 2020 16:26:49 -0400 (EDT)
On Sat, 21 Mar 2020, Norman Yarvin wrote:
There's nothing set in stone about the length of time to field a
vaccine. The often-quoted 18 months (or "at least a year") assumes the
usual approval process: Phase 1 trial, then Phase 2 trial, then Phase 3
trial -- all hurried up, but still basically business as usual. Really
we could put a lot of candidate vaccines out there as soon as they could
be fielded (starting basically now; at least one is already in a Phase 1
trial), and collect statistics on their safety and efficacy as we went.
And if your prototype vaccine turned out to kill more people than the
virus? That is unfortunately *not* an unrealistic possibility.
The guys doing vaccine development are not following an abbreviated
version of the standard process because they think it's business as usual,
or because they just don't know any better. There are real reasons for
doing some preliminary testing, especially for safety, before unleashing a
new vaccine on the general public. Yes, even in an emergency.
The ramp-up should be done somewhat cautiously, but that wouldn't mean
taking anything like a year. If, say, a new factory came online that
could ship a million doses a week...
You really wouldn't want to invest that level of effort in a prototype
vaccine that might not work, or not very well (another quite realistic
possibility -- see the sad history of attempts at AIDS vaccines, and the
hit-or-miss record of flu vaccines). It can take considerable time and
effort to get production ramped up, and those aren't unlimited resources.
You want your skilled people and production facilities focused on making
things that work, rather than having some, perhaps many, of them
temporarily tied up chasing dead ends. You get more useful vaccine sooner
if you find out *first* which one has some reasonable effectiveness, and
*then* ramp up production of that one.
Drug design is often quite complicated, but vaccines can be simple:
take a piece of the virus, mix it with an adjuvant, and inject...
Unfortunately, this is one of those areas where a simple concept doesn't
necessarily translate to a simple real implementation. One particular
complication for this virus is the strong possibility that the bad cases
are caused, not by the virus itself being nasty, but by the body's
defences overreacting in not-quite-appropriate ways. (That's thought to
be what happened with the 1918 Spanish Flu.) You *really* don't want a
vaccine that triggers that...
We would need politicians willing to take scientific risks, though.
The decisions on this mostly aren't being made by the politicians. Thank
heavens for small mercies. The more ignorant politicians would be happy
to promise a vaccine next month (and then blame somebody else when it
didn't materialize); it's the public-health people, who understand the
problems, saying "18 months, maybe a year if we're lucky".
Henry
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