What the Omicron wave is revealing about human immunity
This is a really good article on the immune system.One thing I can't help but notice though is that it only barely skirts the fact that essentially no viral vaccine prevents infection, with the possible exception of the HPV vaccine.The vast majority of the vaccines we currently use allow infection but give the body the ability to quickly respond to and end the infection before it leads to severe disease (eg paralysis in Polio or B-cell destruction in Measles). For slowly developing viruses you may see no symptoms at all because the body is able to clear the infection but for viruses like flu and Sars-CoV-2 that attack the respiratory system it's much more difficult to prevent symptomatic disease.Somehow there's this idea that the Sars-CoV-2 vaccines need to prevent infection or symptomatic disease but that is an incredibly high bar that no respiratory viral vaccine has ever met.The benefit of the vaccines is that they greatly reduce severe disease, almost eliminate death, and shorten the amount of time the virus has to reproduce so transmission and variant generation are also reduced.