Getting to 500 million immunizations — half a billion! — means that we must expand vaccination hubs beyond the pharmacy and hospital chains and start opening major hubs at community centers and outdoor sports arenas. The Biden administration has already articulated this. And it’s true that Biden’s covid policy has started well: There is a road map for a national response to the pandemic with aspirational goals in mind. This reverses the tragic insistence by the Trump administration to make the states lead when they never had that capacity. The new administration is being forthright, and we will never see again the terrible White House coronavirus task force disinformation campaign of 2020 that discredited masks and tried attributing covid-19 deaths to other causes.

But these added sites and philosophical shifts also won’t be sufficient. We need more vaccines, and I do not see how giving 500 million shots to Americans by this summer will be met with the current projections for scaling production of the two mRNA vaccines or even those in addition to the Johnson & Johnson adenovirus vaccine that the Food and Drug Administration is expected to authorize for emergency use soon.

We also need the AstraZeneca-Oxford (AzOx) adenovirus vaccine, which has been authorized in Argentina, the Dominican Republic, El Salvador, India, Mexico, Morocco, Pakistan, Sri Lanka and Britain.