[conspire] 2 Virology professors explain why bivalent vaccine won't stop transmission

[paulz at ieee.org]

 San Mateo Public Health refers to CDC for vaccination information.https://www.cdc.gov/coronavirus/2019-ncov/vaccines/stay-up-to-date.html

For 18 and older, CDC:  2 doses of Pfizer-BioNTech 3 to 8 weeks apart  or  2 doses of Moderna 4 to 8 weeks apart
The 2 shots followed 2 months later by a bivalent booster of either Pfizer or Moderna.  It's OK to have the other brand of booster.

    On Thursday, November 17, 2022 at 04:49:01 PM PST, Rick Moen <rick at linuxmafia.com> wrote:  
 
 Quoting Les Faby (lfaby2018 at gmail.com):

> Thanks for responding. The only thing important in requiring a vaccine is
> ***transmission***

See, this stuff is tricky, Les.

I try to write my mailing list postings quite carefully, even when
rushed, so as to be comprehensive and fair, and also trying to be
thoughtful -- which is difficult indeed when writing extemporaneously,
so one tends to get all the spontaneity of oral speech with all the
you-said-it-on-the-record problems of written speech.  Anyhow, I'm
rushed again at the moment, so apologies in advance for not being able
to take a _slow, careful_ time on this one.

Remember I said there were a number of questions a person worried about
an infectious disease could worry about, and that it's crucial in
science to pick the correct question to investigate?  Here were the 
person-worried-about-infection-disease questions I listed:

"Will X make it less likely to become infected if exposed?"  
"Will X affect my likelihood of symptomatic disease?"
"Will X affect my period of infectiousness to others?"  
"Will X affect my probable time to recovery?"

(I should have added "Will X affect my likelihood of severe disease?", 
but the above was the list.)

Ask yourself what we mean when we speak of risk of "transmission".

We mean the risk of a hypothetical person who is _infected_ being the
vector for transmission to another person.  So, we're talking about two
things in sequence:  1. Person A contracts the pathogen, which has
likelihood P1.  2.  Person A then infects person B, which has likelihood
P2.  The composite likelihood, from the viewpoint of justifiably peeved
person B, is P1 * P2.

But here's the thing, Les:  You seem to be asserting a view about
probability P2.  (Remember, because of the high, high incidence of
asymptomatic infections, one must consider anyone a potential vector.)

And, actually, it's somewhat more complicated.  Again, a framing
question:  What is _my_ objective?  My objective, as part of
Scandinavian standards of hospitality, is to assure Guest B that I've
done what I can to reasonably eliminate risks from the statistical
average Guest A.  But is that the multiplicative product of P1 and P2?
No.  The actual composite risk to Guest B starts with that
multiplication, but then logically it also matters whether factor X
(where X is, say, some particular booster) makes the average period of
viral shedding longer, and/or the average viral titer of someone
shedding.

Now, as my 1980s boss David Carroll used to say when we started to
diagnose a technical problem, "What do we know?"  As Dr. Offit was
quick to point out, we didn't have, at the time of adopting the 
bivalent booster, clinical data proving that it was better than the 
earlier booster against current strains -- but that doesn't mean we knew
nothing about that.  There are sound scientific reasons to think that
the second portion, which IIRC is mRNA coding for the Omicron BA.2
"spike" protein, does successfully train B memory cells in the patient's
adaptive immune system in a way that _does_ create better-targeted
neutralising antibodies, both during the 3 month immediate horizon and, 
if needed to be re-generated after the infamous antibody fade, will 
be ramped up.

Dr. Offit is correct that we also need clinical confirmation that this
actually happens as expected.  A couple of weeks ago, I had in hand
preprints that appeared to show that.  I don't have them now.

> Why I asked about transmission 2 months after vaccination:
> There are 12 months in a year and if it is only even somewhat effective
> less than 17% of the time then an annual booster is close to useless.

Non sequitur.  This assumes, for starters, that the only point of a
booster is to supercharge over a 3 month (not 2, IIRC) period a set of
neutralising antibodies, which is _not_ true.  If, as expected, a useful
revised recipe for memory B cells gets encoded into the adaptive immune
system, then that is a significant advantage.

Some people say "But that's useless because without a full stock of
neutralising antibodies, you will get ill while your memory B cells
start cranking out a fresh set of neutralising antibodies."  Again,
this is non-sequitur argumentation.  The advantage of having the 
_recipe_ for making appropriate neutralising antibodies has value
_particularly_ to the Guest A, but there are very probably also 
benefits to Guest B.  Why?  There is, to the best of my understanding,
based on general principles and past, similar matters, reasonable
expectation that Guest A will tend to have a shorter period of viral
shedding than without variable X (in this case, the bivalent vaccine).
Again, no, last I heard, we don't have solid clinical data on this, 
because (as usual) not enough time has passed.  As usual, intelligent
people are obliged to do rational planning as best they can using what
data _are_ available.

> Also, I read Katherine Wu's paper. Good choice of authors, BTW. She is
> recommending the vaccine because it keeps you from getting seriously
> ill. She does NOT say it will keep you from transmitting the disease
> or you should take it for that purpose.

That question is, as I'm sure you saw, simply not the focus of the
referenced article at all -- for starters.  Ms. Wu has written a lot, a
lot, a lot, on the subject, more than I have any intention of delving
through at this moment.  As I said, I'm rushed, for which, I'm sorry, 
but that's life.

The referenced article's gravamen was simply that our language should
now change from "has had N doses" to "is up to date for the season" --
and why.

In the current piece, Wu doesn't flog the previously done-to-death 
rational for exactly what benefits one gets from having booster N --
which makes me disappointed in seeing you say "Wu doesn't say in that
article that you should get a certain booster for XYZ reason".  No, 
she doesn't -- in that it's not an article trotting out reasons.

Nor is Ms. Wu's article's focus on "Are you a danger to others if you
haven't done XYZ?"  Instead, it contains layman-accessible advice
about how to judge, going forward, "how long it’s been since your last
immunity-conferring event" (to quote the article) and when it might be
prudent to schedule the currently appropriate booster-du-jour.

Wu quotes several credible parties (fortunately _not_ just Unc'a Joe
Biden, who is not known for his epidemiological genius) as saying that
we're probably headed towards an annual booster every fall for the
foreseeable future.  Because, as you say in your helpful and kindly
effort to teach grandma to suck eggs ;-> , SARS-CoV-2 has evolved --
and, I will add as long as we're piling on tedious platitudes, is
continuing to do so.

> Which of your papers, if any, say it has a big effect on you
> transmitting the virus? 

Talk to me after you have read the above about the problems with your
overly reductionist probabilistic concept of "transmitting" in the
context of my hospitality.  Because otherwise we are not communicating,
and you are just talking at me.

Also, I currently have no time to go re-find science papers for you.
Maybe after work, Deirdre will be interested in that.


> The Other people on the committee disagreeing with Dr. Offit are NOT saying
> it will keep you from infection because they know that is an impossible
> standard.

Wrong question.

As I said, in science, one must to be very careful that you are
investigating the correct question.

Which is also true in computer hardware and software debugging.

At this point, I'm sorry, but I'm not just out of time on this, but have
just gobbled up the second overtime.


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