Maybe, but they’re not game changers. It’s more likely that (a) the most vulnerable citizens were picked off in the first three waves of the pandemic, and (b) herd immunity has been mainly responsible for the recent declines in the rates of new cases and deaths.
In graph below I have plotted 7-day moving averages of the daily numbers of new COVID-19 cases and deaths. (The plot of deaths is moved to the right by 24 days because the highest correlation between cases and deaths occurs with a 24-day lag from cases to deaths.) Although the case rate began to decline in mid-January 2021, the death rate held steady through mid-March, and then began to drop only after about 10 percent of the populace had been fully vaccinated. It seems unlikely that 10 percent would have been a game-changer.
In any event, the COVID pandemic is not nearly as lethal as the Spanish flu, which the hardier Americans of more than a century ago managed to survive without the benefit of vaccines:
With deaths at less than 0.2 percent of the population, it is unsurprising that most Americans don’t know (or know of) anyone who died from COVID. How is it that such an inconsequential disease brought a country to its knees and enable petty tyrants to deprive Americans of their liberty?
The answer: Decade upon decade of indoctrination by the media and public-school “educators) in the belief that the nanny state knows best.