Friday, August 27, 2021

How does the CDC’s Advisory Committee on Immunization Practices impact innovation and access to COVID-19 vaccines?

By Rachel Sachs, Jacob S. Sherkow, Lisa Larrimore Ouellette, and Nicholson Price

In previous blog posts in this series, we have explored the roles different federal agencies, including the NIH, FDA, and CMS, play in the development and distribution of new healthcare technologies in the fight against COVID-19. But we have devoted much less attention to the CDC and its Advisory Committee on Immunization Practices (ACIP), which has a key role to play in the distribution of vaccines, including those against COVID-19. In this post, we explain the role played by ACIP, discuss several important COVID-19 vaccine decisions ACIP has been involved in, and consider what ACIP’s processes might teach policymakers more generally about innovation and access to health technologies.

What role does ACIP play in enabling access to vaccines?

ACIP, first established in 1964, is an Advisory Committee housed within the CDC. The CDC has tasked ACIP with providing “advice and guidance to the Director of the CDC regarding use of vaccines and related agents for effective control of vaccine-preventable diseases in the civilian population of the United States.” ACIP reviews any new vaccine—or new vaccine indication—approved or authorized by the FDA, but their task is distinct from the FDA review process. For example, a vaccine licensed by the FDA may be recommended by ACIP more narrowly than its labeled indication, such as only for use based on risk factors like traveling to certain countries. ACIP also considers health equity and cost-effectiveness in recommending vaccine schedules, which do not factor into the FDA’s decision.

Like the FDA’s Vaccines and Related Biological Products Advisory Committee (VRBPAC)—which we’ve described in an earlier post—ACIP is governed by the Federal Advisory Committee Act, including the requirements of open meetings and public involvement. Like VRBPAC, ACIP is an expert body, with members bringing different areas of expertise (such as immunology, virology, and public health), and one member “who provides perspectives on the social and community aspects of vaccination.” But ACIP has greater authority than VRBPAC. The FDA doesn’t have to convene advisory committees (though it has chosen to use VRBPAC for many important COVID-19 vaccine decisions), and the FDA can make decisions that contradict advisory committee recommendations (as it does over one-fifth of the time, including recently for the controversial Alzheimer’s drug Aduhelm). In contrast, ACIP must review every new vaccine, and its decisions have legal effects for vaccine access.

Most notably, the Affordable Care Act (ACA) requires vaccines recommended by ACIP to be covered by private insurers with no cost sharing. The Vaccines for Children (VFC) program, which we’ve written about, also provides ACIP-recommended vaccines at no cost to eligible children. Public and private insurers can still choose to cover vaccines without ACIP recommendations; for example, after the FDA’s authorization of a third COVID-19 vaccine for immunocompromised patients, CMS announced that Medicare recipients could receive a booster at no cost without waiting for ACIP to review the issue. But ACIP’s recommendation triggers important coverage mandates, particularly for patients not on public insurance. Like CMS, ACIP thus plays an important role in governing access to new health technologies—and this market-setting role also affects the incentives to create new vaccines in the first place.

In addition to considering whether a vaccine should be recommended for U.S. populations, Professor Jason Schwartz has explained that ACIP also has played a “traditional role by establishing guidelines for … vaccine prioritization and deployment,” for which issues of health equity are paramount. For example, ACIP issued prioritization recommendations for H1N1 vaccines in July 2009, and for vaccines that have faced temporary shortages. Because of the importance of its role in the U.S. vaccine innovation ecosystem, ACIP has faced ongoing debates about its independence and potential financial conflicts of interest, but it has generally preserved a “reputation as an inclusive and credible voice on vaccination.”

How has ACIP been called upon to make important decisions during the COVID-19 pandemic?

ACIP has played several critical roles in the recommendation and accessibility of vaccines during the pandemic. Most recently, after a public meeting, ACIP recommended third doses of mRNA vaccines (i.e., “booster shots”) for immunocompromised individuals and other groups sensitive to waning vaccine efficacy following the FDA’s reissuance of the vaccines’ EUAs to include third doses for patients “who have undergone solid organ transplantation” or “who are diagnosed with conditions that are considered to have an equivalent level of immunocompromise.” Because there was no FDA advisory committee meeting concerning third doses—originally not included in the mRNA vaccines’ EUAs—ACIP’s meeting was an important place to lay out publicly available information on the doses’ necessity, such as how organ transplant patients’ antibody responses differ from patients with other immunocompromising conditions. ACIP’s meeting also covered important questions, such as how to define who is “immunocompromised.” ACIP also addressed practical concerns such as how such information should be presented and validated, and whether booster shots—given the current combination of vaccine shortages and refusals—will promote equity. 

ACIP was also instrumental in lifting the mid-April “pause” on distributing doses of the Johnson & Johnson vaccine. Back in mid-April, both the FDA and CDC recommended halting the distribution of the J & J vaccine over concerns related to cerebral venous sinus thrombosis (CVST), a rare type of blood clot. ACIP then convened two meetings to assess the relative risk, including one the day after its parent agency and the FDA’s announcement. A second meeting, after ACIP received more information about the relative incidence of CVST—especially as compared to the effectiveness of the J & J vaccine and the effects of COVID-19—resulted in ACIP voting to lift the pause, which both the FDA and CDC shortly agreed to thereafter. ACIP’s advisory role thus was critical in controlling access to FDA-authorized vaccines.

Beyond these recent examples, many are likely familiar with ACIP as initially establishing recommendations about “phasing” the initial doses of the vaccines in the early days of their authorization. While thirty states put ACIP’s recommendations for the initial prioritization phase into practice, most states diverged from ACIP’s framework in later prioritization phases. While somewhat controversial, at least at the time, ACIP’s “work has long included the identification of priority groups for vaccine allocation when supplies are limited,” and it was unclear whether ACIP would take a back seat to the FDA, the CDC, or the White House prior to the vaccines’ authorization. This was complicated by competing allocation mechanisms proposed, separately, by the White House and the National Academies of Science, Engineering and Medicine. States’ buy-in to ACIP’s protocol (at least initially) likely speaks to ACIP’s trustworthiness and independence—important attributes when issues regarding vaccine access are increasingly politicized.

What lessons might policymakers learn from ACIP’s processes about innovation and access to new healthcare technologies?

ACIP’s public process demonstrates the value of transparency in making decisions with substantial public import. The deliberations, and the information involved in making decisions, are widely available to members of the public, which, ideally, helps increase public trust and increase legitimacy. Some other decisional bodies have done a similar job of maintaining transparency, like VRBPAC, which has also held public meetings with available background information. The transparency of ACIP and VRBPAC stands in contrast to some other pandemic-related agency decisionmaking, such as the leaked internal slide deck that provides the primary insight into the CDC’s decision to reimpose mask mandates after the rise in Delta infections. Transparency is unlikely to solve every issue pertaining to vaccine access and refusal. But opacity does no one any good.

Second, and also like VRBPAC, ACIP is an expert body, and its process highlights the importance of relying on scientific expertise to make key scientific policy decisions. As noted above, its members bring different areas of expertise—though like for VRBPAC and the Biden Administration’s COVID-19 task force, social scientists are notably absent. Nevertheless, involving a wide array of scientific and epidemiological experts has helped lead ACIP to make better decisions with better claims to legitimacy. 

Third, these two features—transparency and scientific expertise—are particularly important in maintaining public trust under conditions of uncertainty: when the science changes, policy should change too. But it’s best to persuasively justify those changes to convince the public they are indeed the right choices. COVID-19 has been a rapidly changing pandemic and ACIP’s measured and public involvement in decisions about how to distribute vaccines—including how many doses to allocate and how to account for variant evolution—has been helpful to the public, agencies, and vaccine manufacturers. Transparency and expertise help demonstrate that these policy evolutions are considered and careful, and not fly-by-night reversals for political reasons.

Finally, from an innovation and access standpoint, it is worth noting that ACIP plays a role that is often underappreciated in the standard biopharmaceutical innovation story. While it does not approve or authorize vaccines like the FDA, ACIP complements the FDA by bridging the policy space between market access and market uptake for vaccines. It is a trust repository—and, consequently, a driver of demand—in helping determine which products make it into widespread adoption and which are consigned to relatively infrequent use. ACIP’s role here stands in stark contrast to the ongoing debates over the expensive Alzheimer’s drug Aduhelm, approved by the FDA in a hotly debated and criticized process. Now a constellation of other actors are deciding whether to recommend, use, or pay for the drug at all, demonstrating a lack of trust in the drug’s approval process. ACIP, however, takes these sorts of equity, cost-effectiveness, and public health considerations into account. In the context of arguments about whether the FDA should consider cost or public health in its own decisions, and about the appropriate role of other gatekeepers and their independence from FDA decisions, it is worth considering whether an ACIP-like entity might be equally useful in other biomedical innovation contexts.

This post is part of a series on COVID-19 innovation law and policy. Author order is rotated with each post.