Are There Enough COVID-19 Vaccines for America Without More Funding?

Update: On March 29, 2022, the Food and Drug Administration (FDA) authorized a second booster dose (4th dose) for those ages 50 and older (and for immunocompromised individuals). We have added the 50+ scenario to our analysis.

With Congress having reached a funding stalemate regarding additional COVID-19 support, the White House has said that the federal government “does not have adequate resources to purchase enough booster vaccine doses for all Americans, if additional doses are needed.”  We sought to assess this by estimating how far the current U.S. supply of COVID-19 vaccines could stretch under different scenarios. To do so, we looked at the number of COVID-19 vaccine doses the federal government has already purchased, the number of people already vaccinated and boosted. We then estimated the number of additional doses that would be required to fill any gaps needed to reach vaccination targets, including to fully vaccinate those who still haven’t completed a primary series, under different assumptions about further booster coverage with 3^rd and 4^th doses. We assumed that primary vaccination will soon be authorized for all ages, and examined the future supply of mRNA vaccine doses only (i.e., Johnson and Johnson doses were not included). We assessed the following four scenarios:

1. Providing a 4^th dose to those ages 50 and older
2. Providing a 4^th dose to those ages 65 and older
3. Providing a 4^th dose to those ages 18 and older
4. Providing a 4^th dose to all ages

For each scenario, we looked at supply needed to purchase enough doses to reach two vaccine coverage targets: 70% and 100%. Data are as of March 20, 2022 (see methods for sources and additional details).

Findings

• We find that the federal government does not have enough vaccine doses remaining in its current supply to fully cover the U.S. population with a 4^th dose under any of these scenarios.
• The deficit between current supply and doses required is most acute (484 million doses) if a 4^th dose is authorized for all ages and enough doses are purchased to cover 100% of the population. However, a deficit still exists even if 4^th doses are needed only for those ages 65 and older (162.5 million doses), as well as for the larger age group of people 50 and older (a deficit of 225 million doses), as authorized by the FDA on March 29..
• When a 70% population coverage target is used instead, there is still a supply deficit (118.3 million doses) if 4^th doses are purchased for those of all ages, and a modest deficit to reach 70% of those ages 18 and older with a 4^th dose (34 million). There are enough doses to cover 70% of those ages 65 and older with a 4^th dose as well as 70% of those ages 50 and older.
• Based on the lowest available prices paid per dose by the U.S. government for domestic vaccine supply ($15.00/dose for Moderna and $19.50 for Pfizer), we estimate that additional funding required ranges from $509.5 million (if all future doses were Moderna and enough were purchased to reach 70% coverage of those 18 and older with a 4^th dose) to $9.4 billion (if all future doses were Pfizer and enough were purchased to reach 100% of all ages with a 4^th dose).

With the FDA authorizing a 4^th dose for those ages 50 and older, our analysis finds that the U.S. government currently has purchased enough vaccine doses for 70% of this age group to receive a 4^th dose, and for completing vaccination for others. While the government does not have enough doses to cover all those ages 50 and older, it is also unlikely that 4th dose take-up will approach 100% of the population anytime soon. If 4th dose authorization is further expanded, potential supply constraints will grow.