"Bob F" wrote in message
...
On 10/16/2020 3:57 PM, Frank wrote:
On 10/16/2020 5:57 PM, Neill Massello wrote:
wrote:

Depending on who you believe, a vaccine may not be effective on this
virus. It all gets back to that immunity question.

If vaccines don't prove out, the best approach may be masks: reduce the
viral load received by those who do get infected, so that they can
develop immunity while going through a milder form of the illness.


I had wondered about that and you appear correct:

https://www.medpagetoday.com/infecti.../covid19/88692

As a chemist who worked with toxicologists I knew that toxicity was dose
related. I know that viruses will replicate and wonder what dose might
be needed to assure replication.

No doubt that it is good to wear a mask.

That is a very good article.

Nope, it mangles the real story.

"Cruise ship passengers who embarked from the coast of Argentina in
mid-March were unaware that they were living in a COVID-19 hotspot for
more than a week after the ship departed.

The reason why these passengers were oblivious? Because a majority of the
cruise ship's cases were asymptomatic.

It isnt known that they were positive and asymptomatic.

Researchers are now pointing to this cruise ship outbreak, in which all
passengers were provided surgical masks, as evidence that universal
masking may result in a higher proportion of asymptomatic COVID-19 cases.

Problem with that claim is that US jail which certainly had very
high levels of positive asymptomatic which had no masks at all.

Other outbreaks of mostly asymptomatic cases where widespread masking was
implemented, in places like jails and meatpacking plants, provide
epidemiological data that masks could reduce viral inoculum --
and as a result, decrease the severity of illness."

Pity about the ones where there was no widespread use of masks.

Writing in the New England Journal of Medicine, Monica Gandhi, MD, and
George Rutherford, MD, of the University of California in San Francisco,
hypothesized that widespread population masking may act as a sort of
"variolation," exposing individuals to a smaller amount of viral particles
and producing an immune response.

But she has no evidence for that.

Gandhi told MedPage Today that the viral inoculum, or the initial dose of
virus that a patient takes in, is one likely determinant of ultimate
illness severity.

But she has no evidence for that.

That's separate from patients' subsequent viral load, the level of
replicating virus as measured by copies per mL.

The "variolation" hypothesis holds that, at some level, the inoculum
overwhelms the immune system, leading to serious illness.

But there is no evidence for that either.

With less than that (and the threshold

There is no evidence that there is any threshold.

may vary from one person to the next), the individual successfully fights
off the infection, with mild or no clinical illness.

No evidence for that either.

"Diseases in which your immune system has a big role to play in how sick
you get -- and your immune system contributes to pathogenesis -- do not
seem to be able to handle a large viral inoculum," Gandhi said in an
interview.

No evidence for that either.

Severe COVID-19 may be caused by a reaction known as the cytokine storm,
an immune response in which the body attacks its own cells and tissues as
opposed to the virus itself. Although this theory has yet to be proven
(and other theories, such as the bradykinin storm, have been suggested), a
large initial dose of SARS-CoV-2 may be the trigger.

No evidence for that either.

Trials that give humans different doses of viral RNA are not ethical, of
course. But animal studies provide preliminary evidence that viral
inoculum could impact disease severity, Gandhi noted. In a study of Syrian
hamsters, for example, those infected with a higher dose of SARS-CoV-2 had
worse outcomes compared to those infected with smaller amounts of virus.

Masked hamsters were also shown to be less likely to get COVID-19 illness
than those without masks, a separate study found. And if they id acquire
the illness, it was more mild.

"We know that a higher inoculum of an infectious agent generally
? makes people sicker," said Peter Katona, MD, an infectious disease
specialist and professor at the University of California in Los Angeles."

No evidence for that either.