So what? Medicine's most important question

A colleague reminded me

"In the Pfizer study, there were 162 swab PCR positive cases in the placebo group and 8 in the vaccine group.

There has to be less disease and transmission in the vaccinated group (there were 154 less people who became infected). It is just common sense."

Eric, I understood that in this statement "treatments" meant vaccines. That may have been an error, I am not sure.

"Many scientists who I find to be knowledgeable and reliable state that these treatments will not stop infection, and may only bring about a reduction in symptom severity, and that only in some patients."

Regarding the vaccines, many have said that the vaccines, even the highly efficacious ones, don't reduce the spread of Covid very much.

That's very difficult to understand.

Of course, I am opened minded enough to look at the data on vaccination and disease spread, BUT it's very difficult to imagine a physiologic scenario –

1. Viral vaccines greatly reduce disease severity.

2. AND don’t reduce disease spread.

Ok, let's start with the extant data –

What do we know?

1. Several Covid vaccines are very protective against symptomatic disease and extremely protective against severe disease.

2. These Covid vaccines use 4-5 very different designs or approaches to induce the immune response in the vaccinated host. But, in the end, each Covid vaccine induces immunity against the envelope spike protein, they just do so in very different ways.

3. Protection against disease is associated with measurable antibody response against the spike protein. That association is temporal, not yet proven to be causal.

Regarding the pathogenesis and transmission of SARS-CoV-2 –

What do we know?

1. The virus infects the upper respiratory tract initially and spreads quickly.

2. Pts with more virus get sicker, meaning the higher the "viral loads" or higher concentrations of virus in their mucous secretions and tears, then the more likely the disease will be worse.

3. People spread the disease more when the virus replicates more and results in high viral loads.

4. Young kids have low viral loads and rarely transmit SARS-CoV-2 to others. They also clear the virus quickly from their bodies. In other words, young kids control viral replication on their own. The vast majority don’t get sick and the vast majority clear virus from the throats very quickly.

In short, we know viral replication correlates with both disease severity and viral transmission.

Together, we know -

1. Vaccines very potently protect against severity of disease.

2. Increased virus replication correlates with disease severity.

3. Infected people with higher "viral loads" spread the virus more efficiently.

4. Efficacies of the vaccines correlates with the development a strong antibody response against the spike protein.

5. And just recently, from an Israeli study (see link below), that the viral load is much lower if a person is infected 12 days after receiving the first dose of the Pfizer mRNA vaccine, the viral is much lower than those who were infected before 12 days s/p first dose or those we did not receive the vaccine.

https://www.medrxiv.org/content/10.1101/2021.02.06.21251283v1

Regarding virus vaccination and immunity against viral infection –

We know -

1. Antibodies and cellular immunity, which develop after vaccination against Hep B, polio, smallpox, measles, mumps, and Hep A, essentially block infection with those viruses or very quickly eliminate that virus's infection.

2. Each of these viral vaccines reduces spread of the viral infection.

So, back to the assertion that Covid vaccines protect a host against symptomatic infection and severe disease, but do not reduce spread –

· How does that happen?

· What's the physiologic scenario, which explains, based on the laws of biology, how a vaccine can reduce disease so much, but then not affect spread of the disease?

I am definitely missing something. For Covid vaccines to protect against disease and NOT have a huge impact on spread of the virus, THEN something VERY NEW has happened. Something never described in human immunology and infectious diseases.

OR, maybe, just maybe, some people want this pandemic and the fear it generates to continue.

For a vaccine to prevent disease and not reduce spread, there must be an alternative mechanism of protection, one unknown to humankind.

Finally, there is something called –

The “So what?” test

In Medicine, if a question doesn’t pass the “So what?” test, don’t bother asking or answering it.

Assume for the purpose of discussion, that the Covid vaccines don’t reduce spread? So What? Who cares and why?

Eventually, most everyone who wants the vaccine, will get vaccinated and those who refuse to get the vaccine, can get the infection.

SMS