>>11462792They have worked for a long time, ever since the first one was invented over 200 years ago. The science is proven to be effective and they have literally saved millions if not billions of lives. But every vaccine is different.
No vaccine is perfect, biology is complex and exceptions always exist. Most have effective rates at 95%+ though, making them highly effective and a low risk compared to the alternative (getting sick and dying). Your chances are significantly better with a vaccine than without one.
A coronavirus (covid-19) vaccine has not been tested yet, so we can't say whether or not it will work. I suspect that's why fear has gripped so many people about it, because unlike the flu no vaccine exists yet, so you have to rely on your own immune system to beat it. People in poor health understandably don't have much confidence in their immune system, so they feel like sitting ducks.
