Vaccinated persons present a higher coronavirus transmission risk than unvaccinated persons starting a few months from vaccination.
corrected
COVID-19 vaccines are injected intramuscularly and produce systemic immunity (Bleier, Ramanathan, and Lane 2021). They do not produce strong or long-lasting mucosal immunity (Tiboni, Casettari, and Illum 2021), which is another part of the natural immune response to infection, even an asymptomatic one. (Russell et al. 2020) provides a mucosal immunity review.
It was known from the start that the current COVID-19 vaccines do not provide sterilizing immunity. Another known fact is that even in vaccinated persons, the coronavirus can infect mucosal surfaces of the upper respiratory tract for at least a short time, where it can grow and be shed before being neutralized by the systemic immunity. It seemed not a major factor at the start of the vaccines roll out. Nevertheless, it was predicted that the rise of vaccine resistant and more infectious variants would create the problem of asymptomatic shedding from vaccinated persons (Goldstein 2021).
This has happened and was confirmed by direct measurements (Chia et al. 2021). This study found that vaccinated persons have the same initial viral load as unvaccinated ones, as tested by nasal swab. In the same group, the vaccinated persons were three times more frequently asymptomatic than unvaccinated ones. When symptomatic, vaccinated persons had fewer symptoms than unvaccinated persons, thus making the disease harder to notice.
Notably, SARS-COV-2 does not need to induce symptoms like coughing or sneezing in a host to make it to another host, so nothing prevents asymptomatic spread.
Inaccurate information provided by the CDC, other government agencies, and their mouthpieces is likely to contribute to COVID-19 spread by vaccinated persons, especially when their antibodies immunity has waned since the vaccination. A vaccinated person infected without symptoms would not recognize the infection. A vaccinated person with mild symptoms might not recognize SARS-COV-2 under the false belief that vaccination still protects him/her from getting sick with COVID-19. A vaccinated person might be reluctant to self-isolate based on the idea that s/he has done enough for society by taking the vaccine. A vaccinated person might also be under the false belief that wearing a mask by him/her or by persons around protects them from infection. Masks are useless in prevention COVID-19 transmission, unless used intently in healthcare settings.
Older age (Chia et al. 2021) and longer time since vaccination are expected to be independent risk-increasing factors. Older people are also likely to be around other older people.
It is hardly necessary to restate that younger people are at a low risk of severe COVID-19. It might be expected that a vaccinated person would acquire at least mucosal immunity after exposure to SARS-COV-2. Further, most people had some immunity to COVID-19 before vaccination. Thus, the danger of infection from vaccinated persons should not be exaggerated.
Of note, many vaccines provide sterilizing immunity. For flu vaccines, the preferred route is intranasal (“Quadrivalent Influenza Vaccine | CDC” 2021), which is intended to elicit mucosal immunity.
Suppression of scientific information negative to vaccination
I noticed that many research papers reporting negative outcomes of COVID-19 vaccines and mass vaccination also include language vaccination, sometimes contradicting the reported outcomes. That suggests the suppression of negative scientific information about COVID-19 vaccines. That, in turn, suggests the suppression of research that is likely to lead to negative results for vaccines and mass vaccination.
