There are some that haven't understood the science behind the selection of vaccine evading variants.
This may help:
This is the same as what happens in your body if you only take part of the antibiotics prescribed for an infection --- antibiotic resistant strains arise.
This is also the reason for the appearance of antibiotic resistant pathogens. When we use antibiotics to inhibit but not eliminate a pathogen, the pathogen evolves to become resistant to that antibiotic.
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A technical term used for this discussion is "imperfect vaccines" i.e. vaccines that don't completely stop infection.
Looking in google scholar gives many papers on this subject
One study: Imperfect vaccines and the evolution of pathogen virulence
"Vaccines rarely provide full protection from disease. Nevertheless, partially effective (imperfect) vaccines may be used to protect both individuals and whole populations.
"We studied the potential impact of different types of imperfect vaccines on the evolution of pathogen virulence (induced host mortality) and the consequences for public health. Here we show that vaccines designed to reduce pathogen growth rate and/or toxicity diminish
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"..selection against virulent pathogens. The subsequent evolution leads to higher levels of intrinsic virulence and hence to more severe disease in unvaccinated individuals. This evolution can erode any population-wide benefits such that overall mortality rates are unaffected
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"..or even increase, with the level of vaccination coverage. In contrast, infection-blocking vaccines induce no such effects, and can even select for lower virulence.
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Another Study: "Imperfect vaccines and the evolution of pathogens causing acute infections in vertebrates
"use of either antigrowth or antitransmission vaccines leads to the evolution of pathogens with an increased within-host growth rate;
"..infection of unvaccinated hosts with such evolved pathogens results in high host mortality and low pathogen transmission. Vaccination of only a fraction of hosts with antigrowth vaccines may prevent pathogens from evolving high virulence due to pathogen adaptation ...
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"..to unvaccinated hosts and thus protection of vaccinated hosts from pathogen-induced disease. In contrast, antitransmission vaccines may be beneficial only if they are effective enough to cause pathogen extinction.
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"..Our results suggest that particular mechanisms of action of vaccines and their efficacy are crucial in predicting longterm evolutionary consequences of the use of imperfect vaccines."
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Relevant article on vaccine evasion in another context
"Of those who reported long-term symptoms, 1.8% of children under 12 and 4.6% of those aged 12 to 18 were still suffering from symptoms six months after the illness, the survey found, noting that the probability increased with age.
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"Among those 12 to 18, chances of long COVID were higher among those who had coronavirus symptoms. However, researchers also found long COVID even among 3.5% of the children who were asymptomatic when they tested positive.
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"The company is asking franchisees in areas with high concentrations of Covid-19 cases to only offer to-go sales"
“Consumers have become more concerned as the latest outbreak has worsened,” McDonald’s said... “We must re-establish and reaffirm our commitment to safety.
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Reminder: Green zone elimination is the Exit strategy. It is hard but not harder than what we are doing now. It can be done.
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Different tools to fight covid have distinct strengths. Vaccines are a powerful tool and should be widely promoted. Beyond the Swiss cheese model are nonlinear interactions that strengthen our ability to win when multiple tools are used together.
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Relying only on vaccines isn't providing us a sufficient defence. Without additional actions, the virus has advantage due to time allowed for mutation. Countries should combine vaccination campaigns with non-pharmaceutical interventions to eliminate SARS-CoV-2 transmission.
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Pandemic 2.0 – Where do we go from here? The Delta variant and the young.
Gunhild Nyborg | Andrew Ewing | Yaneer Bar-Yam | Cécile Philippe | Matthias F. Schneider | Shu-Ti Chiou | Sunil Raina | Bengt Nordén | Sigurd Bergmann
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When the virus is circulating in a vaccinated population, variants that are more rapidly transmitting are selected for --- those are vaccine evading variants.
By vaccinating without shutting down transmission we are promoting vaccine evading variants.
For those who want to take a look at the math of evolution, take a look at my textbook, Chapter 6. Downloadable from
Mass vaccination in a population causes a bias in the fitness landscape---the fitness of each of the variants is different. Those that are vaccine evading have a fitness advantage, i.e. replicate faster than those that don't.
The question in this analysis: Is a more deadly variant more or less transmissible. More transmissible ones will dominate, i.e. evolution will favor it.
COVID had multiple variants with higher viral load—more transmissible and more lethal/harmful.
Key example: Does a more lethal variant kill its host faster and dying stops transmission. That would lead to lower transmissibility for more lethal variants.
For COVID this isn't true. Infection happens early in the infectious period just before and after symptoms start.
"Knox County Schools released its first COVID-19 case data on Monday after two weeks of school. At the time, counts were similar to December 2020. But the number of infections continues to grow and reached a new record Friday with 905 cases. Of those, 807 are students.
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"Only 85.8% of students were present at school on Thursday, district spokeswoman Carly Harrington said in an email to Knox News.
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