Maybe I'm just not understanding the terms correctly. My understanding is that covid vaccines do still reduce the odds of becoming infected with covid when exposed. We don't have conclusive evidence of this because the sort of people who get vaccinated aren't identical to those who don't but it's decently convincing just based on case counts. I also see a number of studies suggesting vaccination reduces the probability of spreading covid even with delta.
> There is a whole different suite of antibodies (known as immunoglobulin As) in the nose and lungs, compared with those (immunoglobulin Gs) that we measure in the blood. The former is more important as a barrier to infection. Natural infection, because it is in the nose rather than a jab in the arm, may be a better route to those antibodies, and nasal vaccines are being investigated too.
>They increase the risk of asymptomatic transmission, since the person would otherwise self-isolate.
This is conjecture. It's a hypothetical effect to take into consideration, but it's certainly not borne out in data that the vaccines increase asymptomatic transmission, much less for this reason.
> Based on evolving evidence, CDC recommends fully vaccinated people get tested 5-7 days after close contact with a person with suspected or confirmed COVID-19.
For many people, this description could apply to daily activity, e.g. riding on public transit. So the CDC is recommended regular testing of vaccinated people. Since the vaccine can suppress symptoms, testing can be used to detect infection earlier, enabling isolation and/or treatments which only work early in the progression of Covid.
> Whilst we feel that current vaccines are excellent for reducing the risk of hospital admission and disease, we propose that research be focused on vaccines that also induce high and durable levels of mucosal immunity in order to reduce infection of and transmission from vaccinated individuals. This could also reduce the possibility of variant selection in vaccinated individuals.
> 69 healthcare workers were tested positive for SARS-CoV-2. 62 participated in the clinical study. 49 were (pre)symptomatic ... Breakthrough Delta variant infections are associated with high viral loads, prolonged PCR positivity, and low levels of vaccine-induced neutralizing antibodies, explaining the transmission between the vaccinated people. Physical distancing measures remain critical to reduce SARS-CoV-2 Delta variant transmission.
A sterilizing vaccine means that you cannot get infected when the vaccine works successfully. Not "less likely to get infected" or "less likely to experience severe symptoms if you get infected" like the Covid vaccines.
