> It certainly made me think there was an earlier 'sterilizing' vaccine, which is why I asked for clarification of what was meant. The issue is not whether any

> It certainly made me think there was an earlier 'sterilizing' vaccine, which is why I asked for clarification of what was meant. The issue is not whether any previous vaccines for covid or any other infectious disease have been "leaky" or not. It is that vaccination of the entire human population of the planet against such a disease using a "leaky" vaccine has never been tried before and we don't know what effect this will have on the virus. We have already seen different strains bypassing protections conferred by the vaccine resulting in the introduction of booster doses and even mixing-and-matching of multiple vaccines. Most vaccines often hit the "good enough" threshold and are pressed into service. In the case of covid, while the vaccines currently in service are "leaky," the intranasal varieties being trialed seem to have superior outcomes and, in animal studies at least, "almost entirely prevented SARS-CoV-2 infection in both the upper and lower respiratory tracts."[1] > In a recent animal study involving human ACE transgenic mice, an intramuscular dose of a chimpanzee adenovirus-vectored vaccine encoding a prefusion stabilized spike protein (ChAd-SARS-CoV-2-S) induced robust systemic humoral and cell-mediated immune responses and protected against lung infection and pathology but failed to confer sterilizing immunity. In contrast, a single intranasal dose of the same vaccine-induced high levels of NAbs, promotes systemic and mucosal immunoglobulin A (IgA) and T cell responses, and almost entirely prevented SARS-CoV-2 infection in both the upper and lower respiratory tracts. Considering this and the fact that even natural SARS-CoV-2 infection induces mucosal IgA response, it would have been prudent had more vaccine manufacturers explored this route. This is especially crucial when a vaccine is being considered as an important strategy to halt the pandemic. Thus, the authors believe that it is unfortunate that none of the candidates that are currently under clinical trials is exploring the nasal route of vaccination, although it is recognized that many types of vaccines are intrinsically nonimmunogenic by the intranasal route. Maybe they should have tried this first. > it is not a common term in the research literature. No one reads research literature because no one, other than those with training in the relevant fields, understands that literature. People argue and make assumptions based on conceptual similarity or parity. And it is perfectly fine to do that. > "non-sterilizing" of medical instruments might mean I have lived through times when you had to boil needles and glass syringes before reusing them to prevent pathogens and other biological material from entering the body through unclean or reused needles and syringes. This process is "sterilization." The idea is to eliminate life from the instruments, not add it. [1] https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7754925/ https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7754925/