Most likely the vaccine does prevent/reduce spread. Given the amount of skepticism, it's better to just say the truth that the vaccine 'may or may not' prevent

Most likely the vaccine does prevent/reduce spread. Given the amount of skepticism, it's better to just say the truth that the vaccine 'may or may not' prevent the spread rather than pick a side and be proven wrong. It also advantages that people don't think they can avoid COVID as long as everyone else gets the vaccine. You have the option of getting tested weekly as long as your employer allows for that option. Getting a vaccine is probably less invasive and less of an annoyance then many things employers already require.