How effective are the Covid vaccines against the variants?

It varies a lot based on which strain you use and what vaccine you receive. Generally it's still somewhat effective. As of now, booster shots are being considered to address any variants that might be more vaccine resistant.

Are believed to be pretty effective but we don't know for sure because variance have Arisen to recently for them to have done complete clinical tests on how effective they are against them. One of the reasons why there's a race to vaccinate is because we want to prevent the opportunity for new variants to arise

It has been said they are less effective. Still more effective than no shot if you encounter the original virus.

It takes time to find out, just as it does with the flu, a similar virus.