Why even a less effective COVID-19 vaccine is worth getting, via FiveThirtyEight:
. One formulation of a vaccine can work — and an individual’s immune response to it can remain effective — for many, many years. Scientists knew coronaviruses could mutate faster and more successfully than measles, but no one was really prepared for how much and how quickly SARS-CoV-2 would end up mutating, Offit said. The faster the rate of mutation and the bigger the changes, the less efficacy you can expect from a vaccine.
The problem, Moss and Offit said, is that the process of creating fresh antibodies takes time. If a virus incubates for a while before causing illness, then memory cells can whip up some antibodies and prevent infection. But if the incubation period is short — as it is for COVID-19 — there’s not enough time before infection sets in. The antibodies your memory cells make are still helpful in reducing the severity of the illness, though.
— whose vaccine can’t prevent infection or spread, but it can keep babies out of hospitals, preventingillness at a greater than 90 percent efficacy. At the other end of the spectrum is rabies, a virus with an incubation period so long —they’ve been exposed and have it prevent illness essentially 100 percent of the time. You’re just not going to get rabies-style vaccine efficacy with SARS-CoV-2, a virus with an incubation period that’s typically not much longer than that of rotavirus.