While not impossible, your claim seems unlikely. You are basically claiming that when Americans heard that one vaccine was very successful, they decided to stop doing any vaccine.
There was never a point in time when the first jab was deemed to be "
so successful that no more jabs would ever be necessary", because the vax-pimps released both the pfizer and moderna jabs as a 2-shot series.
When you look at the people who are not doing vaccines, they are vaccine deniers, people who think vaccines do not work. They are not people who believe vaccines work too well.
That's not true at all.
There are all kinds of reasons why people didn't take the Pfizer and Moderna jabs, and if you don't inherently understand that, then it's just your own ignorance and stupidity talking... Of course when tens of millions of people make the same final decision, there are going to be multiple different reasons for it. Only a left4rd cultist would see things from a "We all do exactly as we are told by our masters at CNN" POV.
While it's true that a small percentage of people don't believe in vaccinations at all, for their own reasons (some with good reason, like the black people of Tuskeegee), there are also some who believe in the core group of vaccines, but not the massive vax-schedule that kids face nowadays.
There are also people who believe in all those vaccines but don't believe in the covid vaccines, because they caught Fauci et al lying too often to believe them when it came to covid.
Also, calling the covid jabs "vaccines" is like calling it "rape" when a guy smacks a girl's ass in the bar.
The polio vaccine and the covid jab are different as "a date rape that ended at second base with no violence" and "getting gang-raped in front of your children by a Pakistani militia that kicked in your front door".
As always, the inability of leftists to use basic words properly is a huge barrier to constructive dialogue.