Commercialization of COVID-19 Vaccines, Treatments, and Tests: Implications for Access and Coverage
Editor’s Note: This brief was updated on Feb.13, 2023 to reflect the date on which the public health emergency will end, as announced by administration.
In response to the unprecedented nature of the COVID-19 pandemic, the federal government spent billions of dollars in emergency funds to purchase medical countermeasures – vaccines, including boosters, treatments, and tests – to provide them free of charge to the public. In addition, Congress enacted several bills1 that included special requirements for their coverage by both public and private insurers, and the administration issued guidance2 and regulations to protect patient access and promote equitable distribution. The effective dates of many, though not all, of these requirements are tied to the public health emergency (PHE) declaration made pursuant to Section 319 of the Public Health Service Act, first declared in January of 2020 and renewed every 90 days since, including most recently on February 9, 2023. Two changes on the horizon, however, will affect this landscape and, ultimately, access to, pricing, and coverage of COVID-19 medical countermeasures:
- The Depletion of Federally-Purchased Supply. While the administration has said that it will need additional funding if more products are to be procured and provided for free (and has asked Congress for approximately $9.1 billion as part of a supplemental emergency funding request), Congress has yet to provide any. It is widely expected that once the current federally-purchased supply is depleted, these products will transition to the commercial market for their manufacturing, procurement and pricing. This could affect access in multiple ways. For example, without a federally-purchased supply, consumers may face cost sharing. Additionally, without the federal government’s guaranteed “market” for these products through their advance purchase, it is uncertain whether manufacturers will have an incentive to produce sufficient quantities, including, for example, during future COVID-19 surges or for new and updated vaccines. It is also uncertain how many vaccines local pharmacies may purchase, particularly in areas with low demand.
- An End to the 319 PHE Declaration.3 Although the § 319 PHE declaration has been renewed every 90 days since first declared, the administration announced that it would end the PHE on May 11, 2023. At that time, the protections put in place by Congress and the administration that are tied to the PHE will either end right away or, in some cases, at specified periods after this date.
Taken together, these two changes could act as a “double whammy” of sorts, curtailing access to COVID-19 countermeasures. Depending on the type of product (vaccines/boosters, treatments, or tests) and insurance coverage (Medicare, Medicaid/CHIP, private, or uninsured/underinsured), access problems could come in the form of new or higher cost sharing, more limited coverage, or both. This document provides an overview of these anticipated changes and their implications for access to COVID-19 vaccines (including boosters), treatments, and testing by payer.4 Overall, the key findings are as follows:
- While each of these two changes – the depletion of the federal supply and end of the PHE – matters on its own, their interaction also matters and may amplify access challenges.
- The extent of these challenges varies by product and is most acute for treatments and tests. While COVID-19 vaccines, including boosters, will continue to be available for free to virtually all those with public and private insurance even when there is no longer any federally-purchased supply remaining or PHE protections in place, this will not be the case for COVID-19 treatments and tests, where cost sharing will be widely permitted.
- These access challenges will also vary by payer, with the uninsured and the underinsured standing to lose the most. Whereas these products will continue to be covered by both public and private insurance after the federal supply is depleted and the PHE protection period is over, albeit in some cases with cost sharing, this is not the case for adults who are uninsured, who will have limited access to free vaccines, and no coverage for the cost of treatments and tests.
- Finally, even if consumers are still guaranteed free access or protected against some costs, they could face access challenges if sufficient supplies are not available from manufacturers or procured by pharmacies or other providers.
Details by product and payer are in the following tables:
Table 1: COVID-19 Vaccines
Table 2: COVID-19 Treatments
Table 3: COVID-19 Tests
|Table 1: COVID-19 Vaccines|
END OF FEDERAL SUPPLY AND/OR
|MEDICARE||Medicare covers COVID-19 vaccines, including boosters, for beneficiaries at no cost in traditional Medicare and Medicare Advantage under Medicare Part B. This is due to statutory changes that were made by the CARES Act which added coverage of FDA-approved COVID-19 vaccines to Part B. In addition, CMS issued regulations requiring no-cost Medicare coverage of COVID-19 vaccines that have been granted emergency use authorization (EUA) but not yet licensed by the FDA.
Medicare pays providers for COVID-19 vaccine administration, but not for the vaccine itself, since the vaccine is free to providers through the US government purchased inventory.
|Medicare beneficiaries will continue to have access to COVID-19 vaccines, including boosters, at no cost under Part B.
When the government-purchased inventory of COVID-19 vaccines is depleted, Medicare will determine a payment rate for the vaccines and update the payment allowance for providers. Medicare will then pay providers for the vaccine itself along with administration of the vaccine.
|MEDICAID/CHIP||Medicaid and CHIP cover COVID-19 vaccines, including boosters, with no cost sharing for all Medicaid enrollees, including those enrolled in limited benefit coverage, except those eligible only for Medicare cost sharing assistance, per provisions in the Families First Coronavirus Response Act (FFCRA) and the American Rescue Plan Act (ARPA).
States reimburse providers for the cost of administering the vaccine and receive 100% federal matching payments for these costs.
|Provisions in the American Rescue Plan Act (ARPA) and the Inflation Reduction Act (IRA) require Medicaid and CHIP programs to cover all ACIP-recommended vaccines, including COVID-19 vaccines/boosters, with no cost sharing even when the PHE ends and there is no longer any supply of federally purchased vaccines.
States will receive 100% federal matching payments for the costs associated with administering the vaccine through the end of the last day of the first quarter that begins one year after the PHE ends. After that, state costs will be matched at the state’s regular federal matching percentage (FMAP) and enhanced FMAP for CHIP.
Once the supply of government-purchased vaccines runs out, the Vaccines for Children Program (VFC) will provide access to COVID-19 vaccines for Medicaid-eligible children. The VFC program will purchase the vaccine and make it available to VFC-registered providers. Providers can bill Medicaid for costs of administering the vaccines. For other Medicaid and CHIP enrollees, states will pay providers for the vaccine plus an administration fee. These state Medicaid and CHIP costs will be matched at the state’s regular and enhanced (for CHIP) FMAPs.
|PRIVATE||No one with private insurance should be asked to pay for federally-purchased COVID vaccines, including boosters, or for vaccine administration.
Vaccine providers participating in the CDC COVID-19 Vaccination Program (i.e., those receiving federally-purchased vaccine doses) may seek reimbursement from private health insurers for the cost of administering the vaccine, but they are prohibited from billing patients even if the patient’s health plan does not reimburse the provider or does not cover the full cost of the vaccine administration.
Most private insurers will reimburse vaccine providers for administration costs, in part because the Affordable Care Act (ACA) requires most plans to cover preventive services, including any vaccine recommended by the CDC’s Advisory Committee on Immunization Practices (ACIP), as all COVID-19 vaccines in the U.S. are. While the ACA requires coverage of ACIP-recommended vaccines no later than one year after their recommendation, the CARES Act shortened this to 15 days for COVID-19 vaccines. This is irrespective of whether the vaccine is under an emergency use authorization or fully approved by the FDA.
Even in cases when the insurer is not subject to the ACA coverage requirement (e.g. for out-of-network care or grandfathered health plans), the patient cannot be billed for the vaccine, its administration, or the associated visit if the vaccine dose was purchased by the federal government.
In cases when private plans do not cover or do not fully cover the cost of the vaccine, vaccine providers were able to submit claims for reimbursement from the federal government. However, due to a lack of funding, the federal government stopped accepting these claims on April 5, 2022. Even so, providers cannot bill patients for any amount not reimbursed so long as they are administering government purchased COVID-19 vaccines.
|Most people with private insurance will continue to pay nothing out-of-pocket for COVID-19 vaccines/boosters, but there will be exceptions (e.g. in the case of out-of-network care and grandfathered plans) when the federally purchased vaccine supply is depleted.
Under the ACA, people enrolled in non-grandfathered plans (i.e., the vast majority of people with private insurance) will continue to pay nothing for recommended COVID-19 vaccines and associated appointments, so long as the enrollee receives this care from an in-network provider.
Going forward, any COVID-19 vaccine recommended by ACIP, including updated boosters, will continue to be fully covered for people enrolled in non-grandfathered plans starting 15 days after the vaccine is recommended by ACIP, irrespective of whether the vaccine is under an emergency use authorization or fully approved by the FDA.
The ACA’s preventive services coverage requirement does not apply to grandfathered plans and Short-Term Limited Duration (STLD) plans. Therefore, these plans may impose cost sharing or decide not to cover vaccines at all. When the federal vaccine supply runs out, vaccine providers may begin billing these patients for any amount not covered by their health plan.
Private insurers will be required to take on more of the cost of vaccines (including paying for the doses themselves once the federal supply runs out), which could have a small upward effect on premiums.
|UNINSURED & UNDERINSURED||Uninsured individuals can obtain COVID-19 vaccines, including boosters, for free from any provider participating in the CDC COVID-19 Vaccination Program. To participate in the program, providers agree to provide the vaccine at no cost to every individual regardless of insurance status.
Until April 5, 2022, providers could submit claims for the costs of administering the vaccine to people who were uninsured to the HRSA COVID-19 Uninsured Program, but due to a lack of funding, this has been discontinued. This means providers have to absorb that cost.
Fifteen states adopted a temporary option to provide Medicaid coverage for COVID-19 vaccines, testing, and treatment to uninsured individuals and receive 100% federal matching funds to cover the costs of providing care. This coverage ends when the PHE ends.
|When the government-purchased supply of COVID-19 vaccines runs out, uninsured children will be able to access COVID-19 vaccines through the VFC Program. VFC providers cannot charge for the cost of the vaccine but can charge an administration fee. This program is mandatory, meaning funding is provided based on the number of vaccines needed to cover eligible children.
For uninsured, adults, the Section 317 Immunization Program provides ACIP-recommended vaccines at no-cost; however, because this program is discretionary, funded through annual Congressional appropriations, without additional funding, it is likely that only a limited supply of COVID-19 vaccines would be available through this program.
Some uninsured individuals may be able to obtain COVID-19 vaccines on a sliding-scale basis from certain safety net providers, such as community health centers, but others will have to pay full cost.
In the FY 2023 budget request, the Biden administration proposed creating a new mandatory Vaccines for Adults (VFA) program that would provide uninsured adults with access to all ACIP-recommended vaccines at no cost. The new program would purchase and distribute the vaccines to providers and reimburse them for any administration fees. The budget request also proposes to eliminate cost-sharing for VFC-eligible children.
|Table 2: COVID-19 Treatments|
END OF FEDERAL SUPPLY AND/OR
|MEDICARE||Beneficiaries in traditional Medicare and Medicare Advantage pay no cost sharing for COVID-19 monoclonal antibody treatments and certain other COVID-19 treatments, including oral antiviral medications authorized by the FDA (Paxlovid and molnupiravir) during the PHE.
Medicare beneficiaries with COVID-19 who receive remdesivir during an inpatient stay do not pay separately for the drug, since what patients pay for inpatient hospital stays is generally unrelated to the cost of any services they receive. Traditional Medicare beneficiaries pay a $1,600 deductible in 2023 and daily copays for extended stays. Medicare Advantage enrollees typically pay a flat amount for each hospital stay and/or day. While most Medicare Advantage plans waived cost sharing for COVID-19 treatment in the early stages of the pandemic, it is not known how many of these waivers remain in effect.
Medicare pays providers for COVID-19 monoclonal antibody treatments (when it is not received by the provider for free through the US government purchased inventory) and makes a separate payment for its administration. Medicare will not provide payment for the monoclonal antibody products to treat COVID-19 that health care providers receive for free, as was the case upon the product’s initial availability in response to the PHE. While physicians and other Medicare providers and suppliers cannot bill Medicare for the product they receive for free, they may be paid for its administration.
During the PHE, oral antiviral medications for COVID-19 are being purchased by the US government and distributed directly to pharmacies. As such, there is no direct payment to providers under Medicare for these treatments. CMS has issued guidance to Part D plans that they are permitted to pay dispensing fees to pharmacies that submit claims for these products, but not for the product itself if obtained from the federally-purchased supply.
Typically, Part D does not cover drugs that are not approved by the FDA, such as oral antiviral drugs to treat COVID-19 that are authorized for use by the FDA under an Emergency Use Authorization (EUA). The Consolidated Appropriations Act (CAA), 2023 made a temporary change in the definition of a covered Part D drug to explicitly include oral antiviral drugs (such as Paxlovid) authorized for use under an EUA. This coverage will end on December 31, 2024, by which time (presumably) such drugs will have received FDA approval.
|Medicare beneficiaries will face cost sharing requirements for most COVID-19 treatments, including monoclonal antibody treatments, when the PHE ends.
Based on changes in the CAA 2023, Part D plans can cover oral antivirals authorized for use by the FDA (without this change, Part D plans would not have had authority to cover these treatments). When the US government-purchased supply of oral antivirals is depleted, or if Part D enrollees receive oral antivirals that are not obtained from the federally-purchased supply, Part D plans will pay for the cost of the drug and its administration, and Part D enrollees are expected to face varying cost sharing amounts, since costs vary across Part D plans.
Medicare will pay providers who administer COVID-19 treatments for commercially purchased products for both the treatment and its administration.
|MEDICAID/CHIP||Medicaid and CHIP cover COVID-19 treatments with no cost sharing for full-benefit enrollees, due to provisions in the American Rescue Plan Act (ARPA). These treatments include monoclonal antibody treatments and oral antiviral medications.
States reimburse providers for COVID-19 monoclonal antibody treatments (when they are not received by the provider for free through the US government purchased inventory) and for the costs related to administering the treatments; states receive federal matching payments at the regular and enhanced (for CHIP) FMAPs for these costs.
Oral antivirals are currently paid for by the federal government, so there is no cost to Medicaid/CHIP for the medications themselves.
|Provisions in the American Rescue Plan Act (ARPA) require Medicaid and CHIP programs to cover all drugs and biological products for the treatment or prevention of COVID–19 with no cost sharing for full-benefit enrollees through the end of the last day of the first quarter that begins one year after the PHE ends.
Once the coverage period mandated by ARPA ends, treatments that have FDA approval will be covered but could be subject to cost sharing requirements and utilization limits. However, whether treatments that are still under emergency use authorization (EUA) – that is, without FDA approval – will be covered will vary by state, based on state decisions.
Once the supply of government-purchased treatments runs out, states will pay providers for the costs of the medications in addition to the costs related to administering or dispensing treatments. These state Medicaid and CHIP costs will be matched at the state’s regular and enhanced FMAPs.
|PRIVATE||There is no federal law specifically addressing private insurance coverage of COVID-19 treatment or setting limits on out-of-pocket costs for COVID-19 treatment. However, Affordable Care Act (ACA) requirements that non-grandfathered plans sold to individuals and small businesses cover hospitalizations as part of Essential Health Benefits (EHB) apply. Similarly, the ACA annual out-of-pocket maximum limits how much most insurers may impose in cost sharing.
Early in the pandemic, most insurers voluntarily waived out-of-pocket costs for COVID-19 treatment. However, most insurers began to reimplement cost sharing by late-2021.
Oral antivirals are currently paid for by the federal government, so there is no cost to insurers or patients for the medications themselves.
|Because there is no federal law specifically addressing how COVID-19 treatment should be covered by private insurance, there would be no change with the end of the PHE.
However, as government purchased treatments are depleted, private insurers will take on more of the cost of these medications, which could have a small upward effect on premiums. Patients receiving COVID-19 therapeutics may have cost sharing liability for the medication.
|UNINSURED/UNDERINSURED||Uninsured individuals in the 15 states that have adopted the temporary Medicaid coverage option can obtain COVID-19 treatment services, including oral antivirals and monoclonal antibodies, with no cost sharing.
Uninsured individuals in other states are not required to pay for the costs of government-purchased COVID-19 treatments, including oral antivirals and monoclonal antibodies; however, they can be charged for any necessary physician or hospital outpatient visit to obtain a prescription or to administer the treatment, though some may be able to access care provided on a sliding-scale from safety-net providers.
|When the PHE ends, the temporary Medicaid coverage option will also end, and uninsured individuals in the states that had adopted the option will face costs for related visits, although the treatments will remain free as long as government-purchased supplies remain available.
While the federal government has purchased much of the current supply of monoclonal antibodies, bebtelovimab recently transitioned to the commercial market. Through a new initiative to improve access for uninsured individuals, health care providers who use a commercially procured dose of bebtelovimab to treat an uninsured patient may be eligible to have the dose replaced for free by HHS. Health care providers can use their own established methods for determining uninsured status. HHS has made 60,000 doses of bebtelovimab available, which are expected to be available through September 2023.
When the government-purchased supply of other treatments is depleted, uninsured individuals will be forced to pay the full cost for the medications plus any necessary physician or other visits. Some will be able to obtain the medications and services on a sliding-scale basis from certain safety net providers, but those without access to safety net providers will have to pay the full costs out of pocket.
|Table 3: COVID-19 Tests|
(WITH FEDERAL SUPPLY & § 319 PHE IN PLACE)
|END OF FEDERAL SUPPLY AND/OR
END OF § 319 PHE
|MEDICARE||Clinical diagnostic testing, including testing for COVID-19 – separate from rapid antigen testing (i.e., at-home tests) – is covered at no cost for traditional Medicare beneficiaries under Medicare Part B.
Under a Biden Administration initiative, beneficiaries in traditional Medicare and Medicare Advantage pay no cost sharing for COVID-19 at-home testing (up to eight tests per month) during the PHE.
A provision in the Families First Coronavirus Response Act (FFCRA) eliminated beneficiary cost sharing for COVID-19 testing-related services, including the associated physician visit or other outpatient visit (such as hospital observation, E-visit, or emergency department services). A testing-related service is a medical visit furnished during the PHE that results in ordering or administering a COVID-19 lab test. The law also eliminated cost sharing for Medicare Advantage enrollees for both the COVID-19 lab test and testing-related services and prohibited the use of prior authorization or other utilization management requirements for these services during the PHE.
|Beneficiaries in traditional Medicare will face the full cost of at-home tests when the PHE ends.
Beneficiaries in traditional Medicare will continue to receive clinical diagnostic testing for COVID-19 at no cost once the PHE ends, since Medicare covers their diagnostic lab testing under Part B, but they will face cost sharing for testing-related services.
Beneficiaries in Medicare Advantage plans may face cost sharing for clinical diagnostic testing for COVID-19 when the PHE ends, depending on whether their plan charges cost sharing for this service, and will face cost sharing for testing-related services. Some Medicare Advantage plans may cover the cost of at-home COVID-19 tests through an over-the-counter benefit or other coverage approach.
|MEDICAID/CHIP||Under the American Rescue Plan Act (ARPA), Medicaid and CHIP programs are required to cover FDA-authorized COVID-19 tests, including at-home COVID-19 tests, without cost sharing for full-benefit enrollees. States can require a prescription for the at-home test or apply medical necessity criteria.||Medicaid and CHIP programs must cover COVID-19 testing and testing-related services, including at-home tests, for full-benefit enrollees at no cost through the end of the last day of the first quarter that begins one year after the PHE ends.
Once the mandated coverage period ends, states will continue to cover COVID-19 testing as a mandatory laboratory service if the test is ordered by a physician and provided in an office or similar facility. States may continue to cover COVID-19 tests provided without a physician’s order, including at-home tests, as an optional service, but coverage could vary by state. States may also impose cost sharing for the tests and/or testing-related services.
|PRIVATE||In most cases, people with private insurance currently receive COVID-19 testing without cost sharing.
If the COVID-19 test is considered to be medically appropriate (e.g., for diagnostic purposes or out of a reasonable concern for COVID-19 exposure), private health plans – including grandfathered plans – must cover the cost of the test and the associated visit without cost sharing for the duration of the PHE. This coverage requirement applies to both rapid antigen and PCR COVID-19 tests performed or ordered by a provider. During the PHE there is no limit to the number of tests an individual can receive if deemed medically appropriate. Insurers must also reimburse for tests performed by out-of-network providers during the PHE.
Additionally, beginning January 15, 2022 and lasting for the duration of the PHE, people with private insurance plans may order or seek reimbursement for eight (8) FDA-authorized rapid at-home COVID-19 tests per month. No prescription or medical management is required. Federal guidance allows for a reimbursement cap of $12 per test in certain circumstances.
If testing is done for a reason that is not medically indicated (e.g., a work-place testing requirement or for public health surveillance purposes), the health plan may apply cost sharing or refuse to cover the cost of the test altogether. Through the end of the PHE, providers must make public the cash price of COVID-19 tests on their websites.
The COVID-19 testing coverage requirements do not apply to Short-Term Limited Duration (STLD) plans, as enrollees in these plans are considered uninsured.
|When the PHE ends, many people with private insurance will likely be subject to cost sharing for COVID-19 tests.
The Affordable Care Act (ACA) requires non-grandfathered plans sold to individuals and small businesses to cover laboratory services as an Essential Health Benefit (EHB). The ACA’s EHB requirement would therefore apply to COVID-19 tests after the PHE ends. However, it is important to note that the ACA allows insurers to impose cost sharing (deductibles, coinsurance, and copayments) for EHBs that are not recommended preventive services (that is, given an “A” or “B” rating by the US Preventive Health Services Task Force). When the PHE ends, insurers may also limit coverage of COVID-19 testing to in-network providers, require a prescription or physician’s order for COVID-19 testing, and impose cost sharing for the associated physician visit. Insurers may also limit the number of tests that are covered.
The ACA separately requires non-grandfathered health plans to cover without cost sharing any preventive service with an “A” or “B” rating from the U.S. Preventive Services Task Force (USPSTF). (The ACA requires coverage no later than one year after recommendation, but the CARES Act shortened this to 15 days for COVID-19 preventive services.) To date, though, the USPSTF has not considered, for purposes of rating, any COVID-19 test, meaning that plans may impose cost sharing for the test and the associated visit.
Grandfathered plans are exempt from both the ACA’s EHB and preventive service coverage requirements. When the PHE ends, these plans can impose cost sharing or stop covering the cost of COVID-19 tests. STLD plans are exempt from the requirement.
There will be no requirement for reimbursement of the cost of at-home tests once the PHE ends.
|UNINSURED/UNDERINSURED||Uninsured individuals in the 15 states that have adopted the temporary Medicaid coverage option can obtain COVID-19 testing services, including at-home tests, with no cost sharing. This coverage ends when the PHE ends.
Uninsured individuals in other states are not charged for the cost of any test purchased by the federal government but likely pay full cost for any testing-related services. Uninsured individuals may be able to get COVID-19 tests at no cost or on a sliding-scale from local health departments or certain safety providers; however, individuals without access to these providers pay full cost for the test and any testing-related services.
|After the PHE ends and the federal supply of tests is depleted, uninsured individuals in all states will have to pay the full cost of COVID-19 tests and testing-related services, although they may be able to obtain free or reduced-cost tests from local health departments or safety net providers.|
Families First Coronavirus Response Act (FFCRA), https://www.congress.gov/bill/116th-congress/house-bill/6201 and KFF summary of FFCRA, https://www.kff.org/coronavirus-covid-19/issue-brief/the-families-first-coronavirus-response-act-summary-of-key-provisions/; The Coronavirus Aid, Relief, and Economic Security (CARES) Act, https://www.congress.gov/bill/116th-congress/house-bill/748 and KFF summary of the CARES Act, https://www.kff.org/coronavirus-covid-19/issue-brief/the-coronavirus-aid-relief-and-economic-security-act-summary-of-key-health-provisions/; The American Rescue Plan Act of 2021 (ARPA), https://www.congress.gov/bill/117th-congress/house-bill/1319/text and KFF brief on ARPA Medicaid provisions, https://www.kff.org/medicaid/issue-brief/medicaid-provisions-in-the-american-rescue-plan-act/; The Inflation Reduction Act of 2022(IRA), https://www.congress.gov/bill/117th-congress/house-bill/5376/text and KFF summaries of health provisions in the IRA, https://www.kff.org/medicare/understanding-the-health-provisions-in-the-senate-reconciliation-legislation/, and Medicaid changes, https://www.kff.org/policy-watch/medicaid-and-the-inflation-reduction-act-of-2022/.
See, for example, https://www.medicaid.gov/resources-for-states/coronavirus-disease-2019-covid-19/other-agency-guidance/cms-guidance/index.html and https://www.dol.gov/sites/dolgov/files/EBSA/about-ebsa/our-activities/resource-center/faqs/aca-part-51.pdf.
There are a number of other emergency declarations that have been made to address COVID-19, including an emergency declaration pursuant to Section 564 of the Federal Food, Drug, and Cosmetic (FD&C) Act and a declaration under the Public Readiness and Emergency Preparedness (PREP) Act pursuant to Section 319F-3 of the Public Health Service Act, but these are not considered here. For an overview of these other declarations, see, https://www.kff.org/coronavirus-covid-19/issue-brief/what-happens-when-covid-19-emergency-declarations-end-implications-for-coverage-costs-and-access/, and https://crsreports.congress.gov/product/pdf/R/R46809.
Also see, https://aspe.hhs.gov/reports/covid-19-vaccines-treatments.