The news of a vaccine seems to be sparking an its-all-over sigh of relief. Not so fast. Interesting and challenging corona virus policy remains on the front burner.
Holman Jenkins makes a few good points in WSJ. The media and many governments (mine) are focused on new case counts, now 100,000 per day. But
Brown University’s Dr. Ashish Jha estimated while we are identifying 100,000 new cases a day, “we’re probably missing 70%, 80% of all the cases out there.”
He mentions other guesses that say 90%.
Why does this matter? Well, 100,000 cases per day x (say) 2 weeks of infectiousness means that 1.4 million people are infectious, or 0.5% of the population. Not bad odds for a dinner party, maybe not a rave. But if we really have 500,000 or 1,000,000 cases per day, that means 2.5% to 5% of the people you are going to run in to may be infectious. Yikes.
If Americans knew they were being laughably misled, that the virus is far more widespread and their chances of encountering it are much greater than the confirmed case count (currently 10 million) implies, their behavior might be different. Especially we might get more mask-wearing by unwitting carriers to curb unwitting spread.
And a lot less partying.
More intriguing,
a vaccine works by inducing antibodies. In the first year, Pfizer might have enough to inoculate 25 million people at a time when, at current rates, 100 million of us may have antibodies.
This is a really interesting fact. He doesn't quite say it, but 100 million is darn close to herd immunity -- depending on how careful people are. (Herd immunity comes when the reproduction rate is below one. Reproduction rate = number of people an infected person contacts x chance the contact is immune. Lower contact rate and higher immunity rate work hand in had to determine when the disease stops.) It also says the marginal effect of a vaccine is not that high in the first year.
On the other hand -- the other big unknown -- just how long does immunity last? There are reports of people getting it twice. This would seem like The Big Question. If immunity lasts a year, we will be on our way to herd immunity and the virus will be over before Pfizer has a chance to sell a vaccine. If it does not, we will really really need the vaccine.
Everyone seems to see the vaccine as the magic cure. Wait a minute. It has to be distributed effectively. And our governments (Federal, state, local, all countries) have not been models of efficiency, for example on testing and contact tracing.
So having an accurate picture of prevalence will be necessary to make sure we aren’t wasting vaccine (never mind the already politicized question of who should get early doses: mobile young people to curtail the spread or older people and minorities because this is what the media clamors for).
Joe Biden was quoted as saying the vaccine should be
“distributed equitably, and efficiently, and free for every American.”
Notice equitably comes first. Of course politicians or those with access will come absolutely first! But the hard fact is, give it to one millennial bar hopper and save the 25 people he would give it to.
Free is interesting. If the government wants to pay for it, that's fine -- any imaginable cost is way less than the "stimulus" blowouts. I worry that means price controls. Let's be clear -- companies that come up with a vaccine should make billions of dollars in good old-fashioned evil capitalist profit. They have made a miracle for us, and we want them racing for the same miracle next time. (I also would like to ask Mr Biden, just what should not be free? Name something substantial that Americans should be expected to work hard and pay for, and not everybody gets it. Vaccine? No. Health care? No. Housing? No. Toilet paper? )
Mr. Biden now calls for a national testing board because it sounds take-chargey but let’s understand: Our current hunt for newly active infections is useful mainly for letting doctors know what disease they are treating when confronted with a severe case. It does nothing to control the spread. The results come too slowly and miss the overwhelming number of cases.
Dead on track with the way testing works now, and the conceptual breakthrough still not happening -- testing for public health is a totally different concept than testing for disease diagnosis and treatment.
Don’t get me wrong: If a cheap, daily, at-home test were available, it would give us real leverage over the spread. We aren’t there yet and won’t be before a vaccine and natural effects have quashed the current destructive upsurge.
But we are! See recent Michael Mina thread on paper strip antigen tests. Once again, this represents the best opportunity we have, in my view, for reducing the spread of disease, now, at least before vaccine is so widely available that everyone can have it -- and that means everyone, as people travel.
Meanwhile, the neglected antibody testing will become more important so recipients of the new vaccines, which are likely to be only partly effective, know they are actually generating immunity and can resume normal life.
This is another important thought. The vaccine will not be 100% effective. Many people who test positive now refuse to quarantine. Many people may say, I have the vaccine I'm good to go. Always think of the behavioral response! How long does vaccine granted immunity last?
In all the money and data being spread around, I wish we knew how many people in a completely random sample are infectious right now, and how many show antibodies.
from The Grumpy Economist https://ift.tt/3lrYFR5
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