How many doses of a Covid-19 vaccine will the U.S. need, given that millions of Americans likely won’t take it?
The head of the U.S. Centers for Disease Control and Prevention (CDC), Dr. Robert Redfield, recently testified before a Senate committee that by next March or April 700 million doses of a Covid-19 vaccine will be ready. President Trump has echoed that estimate.
A cache of 700 million doses is enough vaccine to give every American the expected two-dose inoculation that should produce a long-term immunity to the coronavirus.
That’s good news—except that millions of Americans will choose not to be vaccinated.
According to the CDC, only about 45 percent of the adult population (ages 18 years and older) received the flu vaccine in 2018-19. However, the vaccination rate is much higher for those 65 years and older: 68 percent.
Would a Covid-19 vaccine see a higher response?
According to a September Pew Research Center poll, only 51 percent of adults would “definitely” or “probably” get the vaccine if it were available today. And 49 percent definitely or probably would not. That represents a huge drop from Pew’s May poll, which found that 71 percent would definitely or probably get the vaccine.
Pew identifies several reasons why people would abstain, with concerns about side effects and whether it would work well being the primary issues.
However, if the increase in new cases and deaths from the virus continue to decline, making the threat of catching the virus and dying from it seem less threatening, even fewer people will feel the need to be vaccinated.
Of course, children are a different matter. Most of them will likely be required by their state, with some exemptions and exceptions, to be vaccinated if they are attending public schools—just as they do now for several other diseases.
And it’s likely that older Americans, who are harder hit by the coronavirus, will be more willing to get the Covid-19 vaccine, just as they do the annual flu vaccine.
Even so, we may be looking at only half the population, about 150 million people, being vaccinated—probably not enough to reach herd immunity, but close.
That means roughly 300 million doses will be needed if the double-dose approach is followed—though some may pass on getting the second shot. The various drug companies making the vaccine may achieve that smaller number of doses in early winter.
The point is that while health experts probably need to talk—and hope—as if the whole country will be vaccinated, there is little to no chance that will happen.
If the threat continues to diminish—or at least appears to do so—there isn’t much reason to think the Covid-19 vaccine uptake rate will be much, if any, higher than the flu vaccine.