There are many unknowns regarding if and when vaccines against coronavirus disease 2019 (COVID-19) will become available, under what regulatory framework they will be approved for first use, what their ultimate product profiles will be (e.g., efficacy among different age groups, dosage schedule(s), and safety/adverse reactions), as well as the schedule and timelines for expanding vaccine supply availability (e.g., when doses will become available and how quickly supply will expand). Chapter 3 of this report outlined the foundational principles and allocation framework to be used in guiding the fair and equitable use of a scarce COVID-19 vaccine supply. This chapter envisions potential scenarios that federal and state, tribal, local, and territorial (STLT) authorities may face in the use of new COVID-19 vaccines. This chapter starts with describing the best scenario. Subsequently, the chapter identifies possible and, in some cases, probable deviations from this ideal scenario.
It is important to emphasize that, whenever they become available, COVID-19 vaccines will be added to an already complex (and evolving) mix of public health strategies that include (1) non-pharmaceutical interventions such as mask usage, physical distancing, hand washing, and others; (2) expanded diagnostic testing linked to contact tracing, isolation, and quarantine strategies aimed at containing transmission, suppressing outbreaks, and interrupting super-spreading events; and (3) the deployment of therapeutic measures that mitigate morbidity and mortality and, ultimately, curtail transmission from those who do become infected (CDC,
Box 4-1 outlines some of the key unknowns regarding COVID-19 vaccines. Given these unknowns, STLT authorities will need to be ready for varied and sometimes unexpected scenarios in determining how best to use their federal allocation.
An ideal COVID-19 vaccine would be a one-dose vaccine that can be easily handled and stored, produces high levels of neutralizing antibodies in all age groups, prevents moderate-to-severe disease as well as infection, prevents transmission from infected individuals to other susceptible persons,1 has very mild adverse reactions, has no severe adverse effects, and provides long-term protection. This is the “best” scenario because such a product profile would be most compatible with widespread use of the vaccine, both for personal protection and outbreak interruption. It would also be the scenario that produces the greatest demand for the vaccine. Few vaccines will have such an ideal product profile, with each shortcoming (e.g., lack of efficacy in some age groups, complex administration, adverse reactions) reducing demand, as will vaccine hesitancy.
While major efforts are being made by the federal government through Operation Warp Speed (OWS) to have a significant supply of vaccine as soon as possible, the committee has been tasked with considering the tough choices that will need to be made with the tightly constrained initial supplies (e.g., 10–15 million doses, enough to vaccinate 3–5 percent of the U.S. population). For an initial period when demand exceeds supply, the committee, in Chapter 3, recommended a phased approach, guided by evidence to maximize societal benefit by reducing morbidity and mortality caused
1 Current COVID-19 vaccine clinical trials are focused on clinical endpoints related to infection or mild-moderate symptomatic disease and do not explicitly address the issue of transmission blocking.
by the transmission of the novel coronavirus. As previously highlighted, a range of uncertain factors related to the available vaccine(s) may affect the implementation of the framework. Table 4-1 at the end of this chapter summarizes how the framework could be affected in various scenarios.
Number and Timing of Available Vaccine Doses
To ensure adequate protection, it is likely that the vaccine will require two doses instead of one. In this case, two doses will be allocated to each person so that, in effect, half as many people could be vaccinated. Vaccination would still follow the proposed allocation framework, but some individuals would receive vaccination later. If the vaccine requires two doses, strategies and systems (e.g., use of established providers or use of federally qualified health centers) will be necessary to help ensure continuity of care between the first and second dose. This is important because if efficacy with only one dose is low, individuals who receive only one dose are effectively unvaccinated and that vaccine dose would be, in essence, wasted.
A related issue is durability of protection. It may be that duration of protection will be short enough so that people vaccinated in an early phase must receive a booster dose before some individuals in later phases receive vaccination. Again, vaccination would still follow the proposed allocation framework, but some individuals in subsequent phases would receive vaccination later.
Trials of a number of candidate vaccines are currently under way, but at this time the likely efficacy of each COVID-19 vaccine in preventing infection or in preventing severe disease is unknown. The level of efficacy in preventing infection will affect transmission of the infection in the population, and the level of efficacy in preventing severe disease will affect demand for acute and intensive hospital care—key factors relating to the future management of COVID-19. Vaccine efficacy may also differ in different population groups (e.g., a vaccine might be less efficacious in older adults). Moderate-to-low efficacy may lead people to reject the vaccine, believing their risk of adverse effects or the unknown outweigh the benefit of vaccination (Smith, 2017).2 Epidemic modeling—once a vaccine becomes
2 “To ensure that a widely deployed COVID-19 vaccine is effective, the U.S. Food and Drug Administration stated that the primary efficacy endpoint estimate for a placebo-controlled efficacy trial should be at least 50 percent, and the statistical success criterion should be that the lower bound of the appropriately alpha-adjusted confidence interval around the primary efficacy endpoint point estimate is >30 percent.” See https://www.fda.gov/media/139638/download (accessed August 18, 2020).
available—could be useful to determine whether individuals in the priority groups identified in the committee’s framework should still be offered vaccination if the vaccine is determined to be less efficacious for their group. Once widespread vaccination commences, apparent efficacy may be influenced by how adherent people are to other basic protective measures such as masks and social distancing (CDC, 2017, 2020a,b). Additional public messaging about maintaining such behaviors may be called for, particularly if people who are vaccinated erroneously believe they are no longer at risk of infection or transmission.
Significant numbers of individuals must be vaccinated before vaccine safety is fully understood. When a vaccine becomes available, the knowledge concerning vaccine safety will be based on existing clinical trials, which, of necessity, are limited. If it is found that certain population groups (e.g., children or older adults) experience significant adverse events from the vaccine, it may be advisable to allocate the vaccine with caution to such population groups or to reallocate it to a different group that is less vulnerable to those particular adverse events. As the vaccine starts to be allocated broadly in the United States, monitoring of safety through passive and active surveillance and possible adjustment of the allocation framework will be essential in order to minimize possible adverse effects in the population, while maximizing benefit by preventing deaths and severe disease. Effective and timely collection and communication of evidence regarding population effects, both efficacy and adverse events, will also be essential in order to secure and maintain the public’s trust. Additionally, vaccinated individuals should be assured of compensation (especially for health care costs) for vaccine-related injuries. The U.S. Department of Health and Human Services (HHS) has issued a Public Readiness and Emergency Preparedness (PREP) Act declaration, preempting state tort remedies (HHS, 2020). Therefore, the government must then fully fund and make accessible PREP Act compensation. Failing to do so will lead to distrust and anger if and when adverse events arise.
The committee discusses vaccine hesitancy concerns, including the anti-vaccination movement, in greater detail in Chapter 7. Vaccine hesitancy has been well documented among numerous population groups in the United States. Many individuals will be hesitant to receive a new COVID-19 vaccine, particularly if there are perceived safety concerns or if vaccine efficacy is thought to be relatively low. Vaccine hesitancy will also be greater
because there is suspicion that political or economic considerations have influenced the vaccine safety assessments made by government regulatory or advisory bodies, such as the U.S. Food and Drug Administration and the Advisory Committee on Immunization Practices (ACIP). It may be that some people are hesitant to receive COVID-19 vaccine and do not want to be vaccinated when it is offered to them—despite their individual risk—but would be willing to be vaccinated later when more evidence about vaccine safety has accrued. Thus, although an individual may be prioritized in our allocation framework, that person may refuse to be vaccinated when vaccination is offered to them, in which case the vaccine should be offered to another individual within that priority group. Of course, if enough individuals refuse to accept the vaccine, the resulting population protection (reduction in deaths and severe acute respiratory syndrome coronavirus 2 [SARS-CoV-2] transmission) due to the vaccine may not be high.
Messages about vaccine safety and efficacy are essential for all people and at all phases. Risk communication considerations are discussed further in Chapter 6. Direct-to-consumer advertising may influence public perceptions and preferences. It is critical that the communication campaign accompanying the vaccine outlines the risks and benefits of the vaccine in a way that members of the population can understand (Malik et al., 2020). Health care providers can also play an important role in communicating vaccine risks and benefits to their patients. Additionally, if vaccine uptake is low, the idea of adhering to an allocation framework could lead some providers to shift to lower priority groups or be left with excess vaccine stock. Programs should do everything possible to reach all individuals in one priority group before proceeding to the next one. That will include making special efforts to address issues related to health inequities that may reduce trust among some groups or that make health care less accessible to them. This is why it is essential that before COVID-19 vaccine candidates are approved and disseminated, enrollment of minority patients in the clinical trials for COVID-19 vaccine should be large enough to draw reasonable conclusions regarding the safety and efficacy of the vaccine candidate in these populations, thereby enabling experts and community advocates to accurately solicit vaccine acceptance. Without this critical step being achieved, vaccines cannot be responsibly marketed to communities of color, thereby exacerbating disparities in health.
Number and Timing of Available Vaccine Types
It is possible that multiple vaccine types, and not just a single vaccine, will be made available. If this happens, the available vaccines might be rated on a spectrum by ACIP with recommendations about which groups should receive which vaccines. The available vaccines may have major differences
in important features (e.g., platform, construct, and adjuvant; safety and efficacy, overall and in different populations; duration of protection; robustness of immune response; among others) and it will be important to determine which vaccine is best for different groups, based on all the information available when a vaccine is released. Vaccines would still be allocated to the different phases, with the rate of allocation to different groups determined by the availability of the vaccine(s) for that group. For example, if Vaccine A is determined to be best for individuals in Phases 1 and 4, and Vaccine B is determined to be best for individuals in Phases 2 and 3, then vaccination with Vaccine A would proceed for individuals in Phase 1 followed by Phase 4, while vaccination with Vaccine B would proceed for individuals in Phase 2 followed by Phase 3. It is also possible that, after an initial vaccine is made available, a safer or more effective vaccine may be released. In this case, vaccine allocation must take into account the benefits and harms of the vaccine for each particular population group. To the extent possible, vaccines would continue to be made available in the same phases as outlined in the framework. However, if a particular vaccine is inappropriate for use by a particular group, that group would need to wait for a new form of a vaccine, and the existing vaccine might be provided to those who otherwise are slated for a later phase. With multiple available vaccines, it is particularly important to monitor safety and effectiveness as immunization efforts progress so as to ensure that different population groups receive an appropriate vaccine.
Epidemic Conditions and Immune Status
At the time of writing, COVID-19 is spreading widely in the United States, across many states and jurisdictions. Increasing numbers of cases are occurring among younger people, who are also thought to be key agents in transmitting the infection. It is currently not known how long immunity from SARS-CoV-2 infection lasts, nor the extent to which transmission may be reduced in different populations due to more people acquiring immunity from having been infected. If sufficient numbers of individuals in a population group are immune due to previous infection, then it may be that scarce vaccine doses should be allocated to individuals in other prioritized population groups. Conversely, if the infection is found to be spreading particularly rapidly in a particular geographic region or population group, it may be reasonable to prioritize allocating vaccines to that region or group. This could be done by holding back a certain fraction of vaccine doses (e.g., 10 percent) for use in vaccinating individuals in COVID-19 “hot spots” who have a high risk of infection and who cannot protect themselves.
Personal protective behavior—such as sheltering in place, social distancing, and wearing face masks—also affects the spread of COVID-19
Vaccine Distribution and Administration
Specific details of how the COVID-19 vaccine will be distributed and administered have not been fully determined at this time. The vaccine is being developed through the federal OWS initiative, and presumably the federal government will issue guidelines for allocation, distribution, and administration of the vaccine. The extent to which states will be obligated to follow such guidelines is not known. Such state-level decisions will affect the implementation of the vaccine allocation framework. As an example, a state may make a commitment to set aside a certain fraction of vaccine doses for tribal governments in that state (this would supplement what would be allocated by the federal government through the Indian Health Service). State-based distribution should be monitored and supported through data. Current efforts to have regional responses should be encouraged and should allow for states to flexibly respond to changes in the allocation methodology, population needs, or supply.
Social, Economic, and Legal Contexts
The committee recognizes that social, economic, and legal contexts will affect the equitable allocation of vaccine in our efforts to combat COVID-19. These legal issues include, but are not limited to, the process of vaccine approval, distribution, and reimbursement at the federal level; the potential intersection of allocation criteria with federal and state anti-discrimination laws; variability in state vaccination mandates aimed at schoolchildren and employees in certain sectors, such as patient care; professional licensing and scope of practice rules; recognition of out-of-state provider licenses when additional professionals are needed; payment and reimbursement provisions and processes for the varying public and private insurers within states; provider and manufacturer exposure to liability; and state-based surveillance and privacy protections. More generally, the need for vaccination will be affected by states’ legal efforts to increase mask usage and social distancing and to decrease exposure.
Once vaccine availability has increased sufficiently and vaccine safety in younger groups has been assessed, children will be offered a COVID-19 vaccine (Mello et al., 2020). Historically, the most effective way to ensure broad uptake of vaccine in children is through mandates that condition school and day care attendance on evidence of vaccination or an accepted reason for exemption, such as a medical contraindication. There will cer-
tainly be wide variation among states and even within states regarding such mandates, particularly with respect to whether non-medical exemptions will be allowed. To ensure an orderly return to schools, states may benefit from having their mandates clarified by legal interpretations of existing authorities, or by considering ways to tighten existing law regarding exemptions. Despite the allocation framework, some school districts may mandate vaccination of schoolchildren immediately, as a means of moving more quickly toward re-opening schools for in-person learning. At a state level, this would allocate the vaccine in a manner different from the committee’s proposed allocation framework (i.e., by prioritizing schoolchildren).
Some employers will require employees to be vaccinated or to have some evidence of prior infection (based on the employer’s assumption that this confers immunity) (Phelan, 2020). If a state is not allocating vaccine supplies in accordance with the recommended phases, this would divert vaccine supplies toward many who are not in the higher risk categories described in Phases 1 and 2. If large employers acquire doses of the vaccine, as has happened in the past with 2009 H1N1 vaccines, this could limit supplies available to state and local health departments. Although there is precedent for employers requiring vaccination as a condition of employment, subject to some limitations based on union agreements or religious exemptions (e.g., many hospitals and nursing homes require employees to be vaccinated against influenza and a host of other diseases such as tuberculosis and measles), a number of concerns arise when vaccine supply is
|Number and Timing of Vaccine Doses|
|Fewer vaccine courses available than expected by Operation Warp Speed|
|Vaccine requires two doses, rather than one|
|Low vaccine efficacy among older adults or other population subgroup|
|Unanticipated vaccine side effects|
|Significant vaccine side effects among older adults or other population subgroups|
limited, as it will be with the COVID-19 vaccine. If employers require vaccination, the allocation framework would be unchanged, but pressure would certainly be brought to bear on health care providers by people needing to maintain their employment, regardless of whether they have a high risk of infection. Such a requirement could change rates of vaccine uptake, and would pose a dilemma for those individuals for whom the vaccine is medically contraindicated (they would either take the vaccine or lose employment) and would be a possible violation of the Americans with Disabilities Act or corresponding state-based disability protection (Yang et al., 2020). Mandated vaccination could also violate Title VII of the Civil Rights Act of 1964 if there is a religious exemption or could violate collective bargaining rights (in unionized workplaces). Additionally, it is important to note that the equitable allocation scheme will fail if a separate private vaccine market emerges for those who can pay the most. STLT authorities should not waver from their adherence to the proposed equitable allocation framework to satisfy the demands of private employers or institutions that are seeking or requiring vaccination of all workers.
As a final example, if states do not provide free vaccine access to people without documentation of legal status, then the allocation framework is unchanged, but other sources of financial support (e.g., philanthropy, health systems, pharmaceutical companies) will be needed to ensure access to vaccination for those individuals.
|Change in Allocation Framework|
|Allocation framework is unchanged. Some individuals receive vaccination later than they would otherwise.|
|Allocation framework is unchanged, but some individuals receive vaccination later. Vaccination should use strategies and systems (e.g., use of established providers or use of federally qualified health centers) to ensure continuity of care between the first and second dose. Both doses would need to be the same type of vaccine, so this would complicate the second dose if several types are available.|
|Only allocate to this population subgroup if vaccine benefits outweigh the risks.|
|Continuously monitor vaccine safety as the vaccine is rolled out. Only allocate to individuals for whom vaccine benefits outweigh the risks.|
|Continuously monitor vaccine safety as the vaccine is rolled out. Only allocate to this population subgroup if vaccine benefits outweigh the risks.|
|Vaccine uptake is lower than expected|
|Number of Vaccine Types|
|More than one vaccine type available|
|Epidemic Conditions and Immune Status|
|Epidemic spread is continuing across much of the United States when the vaccine becomes available|
|Epidemic is spreading most rapidly in particular hot spots when the vaccine becomes available|
|Vaccine Distribution and Administration|
|States are required to follow federal guidelines for vaccine allocation|
|States have some leeway in the extent to which they follow federal guidelines for vaccine allocation|
|Social, Economic, and Legal Contexts|
|Some states mandate vaccination of schoolchildren|
|Some employers require proof of vaccination|
|Some states do not provide free vaccine access to people without documentation of legal status|
CDC (Centers for Disease Control and Prevention). 2017. Community mitigation guidelines to prevent pandemic influenza—United States, 2017. Morbidity and Mortality Weekly Report 66:1–34. https://www.cdc.gov/mmwr/volumes/66/rr/rr6601a1.htm (accessed September 21, 2020).
CDC. 2020a. Nonpharmaceutical interventions (NPIs). Atlanta, GA: CDC. https://www.cdc.gov/nonpharmaceutical-interventions/index.html (accessed August 19, 2020).
CDC. 2020b. COVID-19: Social distancing: Keep a safe distance to slow the spread. Atlanta, GA: CDC. https://www.cdc.gov/coronavirus/2019-ncov/prevent-getting-sick/social-distancing.html (accessed August 19, 2020).
|Change in Allocation Framework|
|Allocation framework is unchanged. The communication campaign accompanying the vaccine must outline the risks and benefits of the vaccine in a factual way that members of the population can understand.|
|Allocation framework is unchanged, but which vaccines are allocated to which population groups must take into account the benefits and harms of the vaccine for each population group.|
|Allocation framework is unchanged. Public health messages must continue to stress the need for personal protective measures (e.g., masks, social distancing).|
|A certain fraction of vaccine courses (e.g., 10 percent) is reserved for vaccinating individuals in hot spots. Public health messages must continue to stress the need for personal protective measures (e.g., masks, social distancing).|
|Allocation framework is unchanged.|
|States adapt the allocation framework to their needs (e.g., they may set aside a certain number of doses for particularly vulnerable populations in their state).|
|Allocation framework is unchanged, but states mandating vaccination of schoolchildren might allocate the vaccine in a manner different from the committee’s proposed allocation framework (i.e., prioritize schoolchildren).|
|Allocation framework is unchanged, but such requirements could change rates of vaccine uptake, and would pose hazards for those individuals for whom the vaccine is medically contraindicated and could raise issues around discrimination against those unable to obtain the vaccine and therefore unable to work.|
|Allocation framework is unchanged. Other sources of financial support (e.g., philanthropy, health systems, pharmaceutical companies) should be sought to provide vaccination for those individuals.|
HHS (U.S. Department of Health and Human Services). 2020. Declaration under the public readiness and emergency preparedness act for medical countermeasures against COVID-19. Federal Register 85(52). https://www.govinfo.gov/content/pkg/FR-2020-03-17/pdf/2020-05484.pdf (accessed August 19, 2020).
Malik, A. A., S. M. McFadden, J. Elharake, and S. B. Omer. 2020. Determinants of COVID-19 vaccine acceptance in the U.S. EClinicalMedicine. doi: 10.1016/j.eclinm.2020.100495.
Mello, M. M., R. D. Silverman, and S. B. Omer. 2020. Ensuring uptake of vaccines against SARS-CoV-2. The New England Journal of Medicine. doi: 10.1056/NEJMp2020926.
Phelan, A. L. 2020. COVID-19 immunity passports and vaccination certificates: Scientific, equitable, and legal challenges. The Lancet 395(10237):1595–1598. doi: 10.1016/S0140-6736(20)31034-5.
Smith, T. C. 2017. Vaccine rejection and hesitancy: A review and call to action. Open Forum Infectious Diseases 4(3):ofx146. doi: 10.1093/ofid/ofx146.
Yang, Y. T., E. Pendo, and D. R. Reiss. 2020. The Americans with Disabilities Act and healthcare employer-mandated vaccinations. Vaccine 38(16):3184–3186. doi: 10.1016/j. vaccine.2020.03.012.