Cruz, good question.
CDC says that 2 IPV polio shots give, gasp, 90% protection. 3 shots give 99%. They say they do not know how long immunity lasts (but I presume longer than Covid). Many other vaccines do not give full or long-term protection, such as flu. before COVID, there were NO vaccines for coronoviruses, despite many of them circulating. Several more differences:
1) Covid is currently circulating much more than polio did. Lower chances of encountering virus meant much lower chances of infection after vaccine
2) During polio times, the world was not so connected. People were not getting text messages that someone on another side of the world got hit by a bus right after getting a vaccine.
3) People were less educated. Now they are a little more educated and think that they can understand statistics even when they do not, or when someone gives them skewed data in CAPS: DO YOU KNOW THAT MOST SICK IN PEORIA ARE WITH VACCINE EVEN AS 100% of PEORIANS ARE
VACCINATED.