It's worse than that. That implies that the contraceptive reduces the chance of pregnancy but some extra precaution is suggested to make up for its non-absolute effectiveness. A prison study showed that there is no statistical difference in vaccinated and unvaccinated in their ability to transmit covid to others. Describing the vaccine as mearly imprerfect doesn't describe it poorly enough to match reality. It's more like if you sold people a juice they could drink before sex that would lower their chance at concieving but still suggested that they wear an anti-contraceptive to be more certain, but the juice you were selling was just orange juice mixed with a little bit of anti-freeze to make it extra sweet and had absolutely no bearing on contraception. And then demanded everyone in your appartment building drink the same juice so you don't concieve. We live in the most hellish and stupid clown world and it needs to get called out.