Friday, November 13, 2020

Herd immunity, novel vaccines, Pharma incentives and media spin

The US is again suffering from a lot of Covid cases, and we are on a steep upward trajectory.  While some are definitely due to false positive tests, which are extremely common, there are still a lot of cases.  Using the numbers from CovidTracking (which I noticed the NYT was also using) it appears that 8.8% of staffed hospital beds in the US are now filled with Covid patients... although, since all admissions are screened for Covid, they may be hospitalized for a different primary diagnosis. I have seen no discussion of the diagnoses/comorbidities in the 65,000 Americans currently hospitalized with Covid.

The NYT's map of hotspots illustrates that areas that saw lots of Covid cases in the spring or summer (NYC, NJ, Boston, much of the South) are seeing relatively fewer new cases now. This presumably reflects the fact that these areas have fewer people susceptible to the virus. 

Peter Doshi in the BMJ reviewed half a dozen studies, not just in the US, that indicated 20-50% of the people studied had pre-existing T cell immunity to Covid 19--before Covid appeared--by studying stored blood samples.  Current thinking is that prior exposure to one or more of the 4 coronaviruses that cause the common cold induces some protection to SARS-CoV-2, for an unknown period of time.  Other evidence, reviewed in the blog of the NIH director, Francis Collins, notes that in people who were exposed to SARS (the first SARS) 17 years ago, T cell protection is still present, 17 years later. Collins further notes, 
"All six previously known coronaviruses spark production of both antibodies and memory T cells. In addition, studies of immunity to SARS-CoV-1 have shown that T cells stick around for many years longer than acquired antibodies.... It’s still not clear if this [SARS-2] acquired immunity stems from previous infection with coronaviruses that cause the common cold or perhaps from exposure to other as-yet unknown coronaviruses."
Doshi reminds us that while it was initially assumed that the 2009 swine flu was so novel there was no preexisting immunity, that turned out not to be the case. And an article in last week's Science magazine showed that children and adolescents were more likely than adults to have protective antibodies from prior exposures to "common cold" coronavirus, possibly explaining their resistance to symptomatic infection. 

I'm suggesting that although there are probably few areas of the US with sufficient levels of immunity to stop all transmission, there is sufficient "herd" immunity now to keep cases from exploding in areas that previously exploded.  Time will tell if I am correct. 

Strangely, the media are pretty quiet about the case numbers today, with many more cases and hospitalizations than there were in the summer, when the media discussion was deafening. 

Could it be that all these cases are at odds with the plan to vaccinate everyone with novel vaccines?  If we achieve high levels of immunity due to disease exposure, the experimental vaccines may look a lot less inviting.

The WHO suggested that 20x as many cases have probably occurred as those we know about, worldwide.  The US has had over 10 million known cases, and cases are rising rapidly.  If the US had had ten times as many cases as were diagnosed, there would be 100 million Americans with partial or complete immunity from exposure.  If an additional 20% of us had pre-existing immunity, then half of the country would already be immune. 

If my odds are 50% that I am already immune to Covid-19, why would I accept a vaccine that is known to make me feel like I had a bad hangover, and might cause other side effects longterm?  I am not impressed that the vaccines are only being asked to demonstrate efficacy against mild disease in the clinical trials, and it is still uncertain whether a vaccinated, exposed person is prevented from spreading the infection.

We have been told that even after being vaccinated, we will still have to wear masks.  I think I'd prefer to take my chances with the disease, knowing that zinc, vitamin D, vitamin C and early hydroxychloroquine/azithromycin almost guarantee me a mild case. 

Not to mention that there continues to be concern that novel vaccines might prime us in such a way that makes a case of Covid worse, causing even more autoimmunity.  This happen with a measles vaccine and an RSV vaccine back in the 1960s.  Neither vaccine gave recipients immunity; instead each caused severe disease when recipients were exposed to the virus the vaccines were intended to protect against. This happened more recently when experimental coronavirus vaccines were used in animal experiments. 

When millions of people are vaccinated close together, as soon as a vaccine is given regulatory approval, they don't benefit from seeing how earlier recipients fared.  Even though there have been many thousands of experimental subjects in vaccine trials, there have been only a few weeks or months in which to observe them for adverse effects.  And because the vaccine manufacturers are not liable for damages, unless they conceal evidence of side effects, the manufacturers are incentivized to speed the vaccines' evaluation, and learn as little as possible about their side effects. 

The media were surprisingly willing to discuss possible vaccine side effects, as long as the Warp Speed vaccines were Trump's project.  I expect to see a 180 degree shift in their approach, as soon as the election is definitively called.  Watch for it.


Anonymous said...

There remains the possibility that SARS-Cov-2 or whatever the SARS-Cov-2 antibody and RT-PCR tests actually detect is not new. The high number of pneumonia deaths in Wuhan that lead to the identification of the SARS-Cov-2 virus were caused by high levels of air pollution in the city, causing a hunt for some pathogen as a scapegoat, consciously or sub-consciously. Possibly the virus got loose or was let loose from the Wuhan Institute of Virology much earlier or simply the bat coronavirus experts at WIV naturally looked for the type of virus they were familiar with. The old "if you have a hammer, every problem looks like a nail" phenomenon.

In this case, there could be widespread immunity to SARS-Cov-2 or whatever the tests actually detect. That might explain the astonishingly low deaths in Japan and several other regions. Then too it may simply not be very deadly without a medical overreaction with lockdowns, isolation, aggressive intubation of patients, etc.

Many viruses are probably detectable in persons whose immune system is weakened or failing from old age and other causes, who seem to comprise most of the fatalities. Are there good tests of immune function that would enable a clearer separation of deaths in persons with a seriously weakened immune system versus otherwise healthy persons?

KRolson said...

Speaking of the 50% probability.

NPR Article about Elon Musk. Musk had been administered four tests for the virus over a 24-hour period, leading to contradictory results.

“Two tests came back negative, two came back positive. Same machine, same test, same nurse. Rapid antigen test from BD,” Musk said.

"Something extremely bogus is going on. Was tested for covid four times today. Two tests came back negative, two came back positive. Same machine, same test, same nurse. Rapid antigen test from BD."
— Elon Musk (@elonmusk) November 13, 2020

"Elon Musk Tests Positive And Negative For Coronavirus, Awaiting Confirmation"; November 13, 202010:30 AM ET

KRolson said...

Another one of the 50% tests.

Grammy award singer Erykah Baduoula on Twitter:

"No symptoms. Was tested for COVID. Same machine. Left nostril positive . Right nostril negative. Maybe they need to call Swiss Beats so they can do a versus between them. Funny thing is , Dr. ONLY reported the positive result. What the fack is goin on here. Rapid Test. $$$$ smh."