A recent article in the NY Times plus some articles by scientist Dale W. Harrison help us understand what the three new Covid-19 vaccines apparently can and cannot do.
Sterilizing vs. Disease Immunity
Harrison (who says he had over 20 years as a researcher in the biotech industry) explains that there are two types of immunity: Sterilizing immunity and disease immunity. The measles vaccine is an example of a vaccine that provides sterilizing immunity; it prevents the person from catching and therefore spreading the disease altogether. The flu vaccines provide disease immunity. They don’t prevent a person from catching the disease; instead, they lessen the symptoms. According to Harrison, all three of the Covid-19 vaccines provide disease immunity, but not full sterilizing immunity.
Pfizer, Moderna and Astra-Zeneca Trial Data
As we know, there are three vaccines in the pipeline. Two of them – the Pfizer and the Moderna vaccines – have been granted emergency okay for use. The third – the Astra-Zeneca (AZ) vaccine – will probably also be granted this same okay. Maybe one reason the AZ vaccine is later to market is that, according to Harrison, it seems to have been tested more thoroughly. That more thorough studying provides an insight. Harrison writes: “So far, the prior vaccine trials have explicitly avoided looking at sterilizing immunity… This [the AZ vaccine] is the ONLY vaccine trial where participants were tested for SarsCoV2 infection on a weekly basis throughout the trial. That makes this the sole look at whether these SarsCoV2 vaccines are able to confer sterilizing immunity.… Evidence suggests that both the AstraZeneca and Moderna vaccines provide only limited sterilizing immunity with a post-vaccination asymptomatic infection rate at roughly half the level of the non-vaccinated population.”
As for “herd immunity”, Harrison says that the AZ trials showed reinfection is common. That means, according to him “there is no possibility of ever achieving herd immunity.”
In other words, while the vaccines seem to provide some protection from infection – and therefore the spreading of SARS-CoV2 virus – that protection is very limited. The main effect is to protect the person from more serious consequences of the disease.
Effectiveness of injected vaccine
Apoorva Mandavilli, author of the NY Times article may explain why: She confirms what Harrison says about the vaccines’ providing disease but not sterilizing immunity (although she doesn’t use those terms). She explains that since the nose is the most common “point of entry” into the person, the immune system tends to produce “a type of antibodies that are specific to mucosa, the moist tissue lining the nose, mouth, lungs and stomach.” However, these vaccines are injected and produce antibodies that are not so specific and don’t go directly to the nasal “mucosa”. They circulate throughout the body and apparently provide protection to the lungs, heart, etc. But “it’s not clear how much of the antibody pool can be mobilized, or how quickly. If the answer is not much, then viruses could bloom in the nose — and be sneezed or breathed out to infect others.”
“This is why” the Mandavilli writes “mucosal vaccines, like the nasal spray FluMist or the oral polio vaccine, are better than intramuscular injections at fending off respiratory viruses, experts said.” (There is presently research being done for a nasal spray, but none has been developed as of this time.)
What, then, are the perspectives for Covid-19? The course of the Spanish flu pandemic of 1918 might provide some clues. That flu was caused by the H1N1 virus. As opposed to Covid-19, evidently reinfection did not occur, so it more or less died out through herd immunity – after an estimated 50 million people died of it. But herd immunity doesn’t mean that the virus disappears entirely; it just becomes less common. In those days, scientists lacked the tools they have today, but it is thought that the virus became less virulent (less deadly) over time. Also, some believe that some or even possibly most of those who died did so due to secondary infections. Their immune systems rapidly weakened and became unable to fight off bacterial pneumonia, which may have been the immediate cause of death. If that is true, then modern medicine would be able to save millions simply through the use of antibiotics. But the virus is still with us in a weakened form.
Will the SARS-CoV2 virus evolve in the same way – to become less virulent? Nobody knows. What we do know is that we cannot continue like this, running roughshod over nature like some foreign conqueror over a subjugated people. As Oaklandsocialist has explained many times, industrial/factory farming plus wild habitat destruction create the conditions that encourage viruses to evolve in such a way as to be able to jump from other species to humans (zoonosis). We are fortunate that SARS-CoV2 is far less deadly than was the virus that caused the original Spanish flu pandemic. We may not be so lucky next time.
Anthony Fauci and his minions are a welcome relief from the science denialists, religious fanatics and money-grubbing capitalists large and small, but in the end Fauci et al also distract from the root cause of this pandemic and the ones to come. Combined with global warming, this disease shows that we simply cannot afford to continue raping nature like this. In other words, we cannot afford capitalism.
Added note (12/21/20): Several people have disputed the claim that the Moderna and Pfizer trials did not test regularly for Covid 19 positivity. I went back and checked on that claim. Moderna, for example, tested subjects before being accepted into the trial and then tested them 7 weeks later. That means that a subject would well have contracted the disease and then shed it in the interim. Here is their summary of the report.
Categories: Coronavirus, Uncategorized
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