Changes in US Government Vaccination Policy in a World of Growing Infectious Threats
Q&A with Camille N. Kotton
Camille Nelson Kotton, MD, FIDSA, FAST, is the clinical director of the Transplant and Immunocompromised Host Infectious Diseases Program in the Infectious Diseases Division at Massachusetts General Hospital, and associate professor of medicine at Harvard Medical School in Boston, MA. She was a member of the CDC Advisory Committee on Immunization Practices (ACIP) 2020-2024 and continues to serve as an ACIP consultant. Since 2014, she has cowritten the CDC Yellow Book chapter on Travel Medicine for Immunocompromised people. Dr Kotton has served as the chair of The Infectious Disease Community of Practice of The American Society of Transplantation and as the president of The Transplant Infectious Disease Section of The Transplantation Society. She is the first transplant infectious disease specialist to be on the executive committee of The Transplantation Society.
Mahoney: We’re here to discuss the Advisory Committee on Immunization Practices (“ACIP”) of the Centers for Disease Control and Prevention (“CDC”). Could you describe the core functions of ACIP and its significance in shaping US immunization policy?
Kotton: ACIP was created in 1964 as a group of experts, external to the CDC, which provides independent advice to the CDC specifically on matters that relate to vaccination and immunization. In addition to vaccines, ACIP advises on monoclonal antibodies and other similar products that might prevent transmission of infections. Following the FDA’s approval of a vaccine, the CDC then makes a recommendation for use of the vaccine. ACIP is a group of experts who usually serve for a four-year period, with the technical and clinical expertise to help interpret medical and scientific data presented to them, with no significant conflicts of interest which could interfere with the required independence of their advisory role. At ACIP we usually function in work groups and traditionally we've had three meetings a year to discuss policy and recommendations.
Mahoney: How does ACIP balance scientific evidence with public health considerations when making recommendations, and how are new vaccine recommendations adopted and implemented?
Kotton: That's a great question. We are able to understand the science and balance this with public health policy considerations, as I'm sure you've learned. We strive to provide the most good for the most people, looking through a lens of equity and protection for all and being as encompassing and thoughtful as possible, balancing also the cost effectiveness and feasibility of our recommendations. We ask whether vaccines can be rolled out and implemented effectively, not just efficacy of distribution at the health care organization level but also cost and other factors, including social determinants of health. Sometimes it is a challenge to balance the science and public health aspects of vaccines and immunization.
Mahoney: What are the processes involved in creating and updating vaccine recommendations?
Kotton: For any vaccine for which there is new evidence or new information, there is a work group established at ACIP; there's a list on CDC’s Website of all the different work groups. Leads from the CDC help organize and run the work groups and present data. ACIP has access to people within and outside of CDC, including elsewhere in the Federal government such as FDA and other groups concerned with health policy, bringing to bear specialized expertise as needed in conjunction with current voting ACIP members. ACIP work groups often include anywhere from 40 to 60 different experts bringing varied perspectives to the consideration of any given vaccine. Traditionally the work groups meet fairly frequently, sometimes as much as once a week, or in other cases once a month or less frequently depending on the need. In the work groups, we come up with topics and presentations for the three times a year that ACIP normally meets as a whole. There is a specific framework utilized in the process called evidence to recommendations.
Mahoney: How does ACIP ensure that public trust is maintained in the organization?
Kotton: All of ACIP’s meeting agendas, meeting minutes, and meeting materials such as presentations and slides are made available to the public for viewing. Regarding the meetings themselves, until the beginning of the pandemic, ACIP meetings like most HHS meetings were open, where people could come and sit in the room with us, but during the COVID pandemic, we had to close the meetings and all proceedings were virtual for a couple of years. Once the most restrictive pandemic limitations were lifted, we opened the meetings up to a very small number of people in the room, still due to COVID concerns. At the present time meetings are live streamed and recorded, and again as all the slides and other relevant information we review are available, we hope this increases public trust in a transparent process, as the public can see where we are getting our information as well as the data we're synthesizing. With this said, I do think the situation is more nuanced and complex than just having us show our data, because there are other social factors at play that might encourage distrust of medicine and public health and that affect ACIP in this context as well
Mahoney: Speaking of the pandemic, it's been five years now since that event. How has ACIP's role changed? What are some of the takeaways for ACIP, what lessons have been learned and what kinds of improvements could you think about that might make the institution function more effectively?
Kotton: It was pretty amazing what happened during the pandemic, as traditionally ACIP was highly methodical and well organized with a regular schedule of meeting three times a year. With the advent of the pandemic, we experienced the miracle of having vaccines against a novel virus developed more rapidly than anyone had thought possible. Until that time, the fastest development and clinical approval process for any vaccine to get to market had been four years, but now in something like eight months we were able to create a very good vaccine, which was truly a miracle. ACIP during that time got organized and ready for this vaccine, which was complicated as we had several new vaccine types, we had to review safety and efficacy as always, but we also wanted to think about how we were going to roll these novel vaccines out. We had to ask questions such as whether you just put the vaccines on the counter at CVS and distribute them on a first come first served basis, or do you want to ensure that all geographic areas and demographic groups in the US – for example, people living on Native American reservations – have equal access to immunization compared to those living in, say, Manhattan? How do we determine who is at risk for the most severe disease and thus should perhaps get vaccines earlier rather than later?
So, there was a lot of work done preparing for the nationwide distribution of the vaccines ahead of their emergency use authorization, and then once we started having safety and efficacy data on the vaccines, we would review that. I believe we may have had a total of something like 36 emergency meetings about COVID and related vaccines. The way things proceeded was that when we heard a new vaccine candidate was coming through from FDA we might literally have met the next day and cleared our calendars 8 AM to 3 PM. Everything was done virtually, so there were no travel arrangements to contend with, but it was a pretty amazing tour de force that ACIP was able to operate at such a breakneck pace and remain organized, yet somehow we managed it. To be honest, in the nonstop emergency setting we were operating in, I don't know how things could have been executed better. It's by definition very hard to prepare for the unknown. None of us on the Committee knew this particular global public health crisis was coming.
In terms of lessons learned for future pandemics, I often wonder if we should be preparing in similar ways for new outbreaks like bird flu, but at this point we haven’t really had a signal that there's likely to be imminent large-scale transmission in humans. You don't want to pull the trigger on a massive public health preparedness effort because of the expense but also because in doing so you'll pull people off other important projects, which you don’t want to do until you're pretty sure the event is going to happen. It's inherently hard to know in outbreak situations exactly how bad things are going to become. Right now, for example, there's a lot of talk about measles. Should we be preparing for a large-scale measles outbreak or is it just going be rather limited like we've had in the past in California and other areas in the United States?
Mahoney: Regarding recommendations made by ACIP to the CDC, are all of those implemented, and if not, how are the findings and conclusions of the Committee dealt with, and maybe you could give an example?
Kotton: The recommendations of ACIP are routinely accepted by the Director of the CDC. This is a pretty standard process. The CDC does not have to accept all recommendations, but in general they are accepted for the most part in their entirety and just signed off on. At one point in September 2021, CDC Director Dr. Rochelle Walensky decided to alter the recommendation of ACIP, and I believe that was likely to have been due to influences in the White House and other political forces that felt that there should be an alternative approach. As I mentioned previously, when we're balancing science and public health, there are a lot of issues to consider, particularly when you're the Director of the CDC. So, I think it's reasonable that the CDC doesn't take all of our guidance verbatim.
Mahoney: Let's dig a little deeper into the processes involved in creating and updating vaccine recommendations.
Kotton: We do a lot of background history in formulating our recommendations. As part of our analytical framework, we investigate disease rates and ask what is the public health importance of a given vaccine – how severe is the illness, what is the overall impact on society? Did three people have this disease last year or did three million have it? As far as the vaccine itself, we ask what is the vaccine efficacy, and how does that apply to different population groups? Along with efficacy, we assess durability and cost. All of these are considerations we look at and try to understand to the best of our ability. Sometimes there's some conjecture, but overall, we try to do the best we can with the available data we have, even though sometimes there's just a lack of science because the studies just aren't able to be, or haven't yet been, done. At the same time industry is developing these vaccines and has done the clinical trials, so often industry is presenting new data to us. Obviously, industry has a somewhat different interest than we do working for ACIP or than I might as a clinician taking care of patients. So, people may have different perspectives and there are a lot of factors we take into the equation.
Mahoney: Let's go back to the public trust issue. How would you assess the impact of the pandemic on trust in CDC and public health officials in general? What might you do differently in light of this concern?
Kotton: I think there have been a lot of trends under way already in the past one to two decades that have led the public to lose trust in government and authority figures overall. In addition, I think there are a lot of sources in social media and other channels suggesting that they have a better way and unfortunately this issue goes far beyond what CDC or ACIP can respond to. I will say I’ve always had a vision that CDC would have more funding to be able to do, for example, advertising campaigns for many vaccines so that people could have really good information about these instruments to improve public health and make more informed choices. The funding that would be required for such a campaign is unfortunately tremendous. We do have good vaccine information resources, but I’m afraid the right messaging about vaccines hasn’t really penetrated lots of different audiences. We may know where to find information on a particular vaccine on CDC’s website, but we don't necessarily know how to transmit that important knowledge to the larger public without a lot of advertising campaigns.
Mahoney: The recent dismissal of all 17 members of ACIP by HHS Secretary Robert F. Kennedy Jr. represents a seismic shift in US vaccine policy. While framed as eliminating pharmaceutical industry conflicts, this wholesale overhaul threatens to dismantle decades of scientific rigor in the adoption of critically needed vaccines. Please comment on both the downstream effects of this unprecedented action on America's ability to respond to infectious threats and any observations you may have as to the qualifications and potential biases of new members of the reconstituted Committee.
Kotton: The US vaccine implementation system whereby the FDA approves new vaccines and CDC ACIP makes recommendations concerning their use was specifically designed to incorporate checks and balances. In recent months CDC has not had either a permanent or officially designated acting Director, so it’s difficult to understand how ACIP’s vaccine recommendations can be approved. Some of the recommendations made at the April 2025 ACIP meeting were advanced but others have stagnated.
In terms of ACIP’s membership, it was carefully created to ensure the convergence of informed opinion from a heterogeneous group of experts from public health, pediatrics, adult medicine, obstetrics and many other medically relevant fields. All of us on the Committee underwent rigorous evaluation of our potential conflicts of interest and if it was determined that we had active conflicts of interest, we were not allowed to serve or we had to terminate the relationship. In my own case it took months for my paperwork to be reviewed with a tremendous number of forms completed in a very diligent, careful review of my potential conflicts, and so it was for each of us, at the time of our service. It is unclear to me the extent to which such conflicts of interest review were undertaken for the new ACIP members, who were appointed very rapidly, and I am concerned that they may not have been appropriately evaluated in this regard. Furthermore, I'm somewhat shocked to see that of the 8 new ACIP members appointed, almost none of them have ever given or recommended a vaccine, nor do they have any demonstrable vaccine expertise. These individuals seem to represent political appointments, and science should never be political. Medical science is based on facts, experiments, outcomes of experiments, and interpretation of sound data. No Government healthcare organization in my view has provided, gathered, collected and synthesized as much high-quality medical data as the US CDC, which is why many other countries rely on ACIP’s recommendations for determining local vaccination policy.
So, the impact of altering the composition of ACIP is quite significant in that it will definitely affect American healthcarebut also have an impact throughout the world, including low- and middle-income countries, who may not be able to staff their own similar committees like ACIP. I am also concerned that if vaccines are no longer recommended for certain populations, such as in the recent decision not to recommend COVID vaccines for healthy children or for pregnant women, this can result in severe clinical outcomes for an important number of people. Moreover, we are likely to see an increase in deaths in Americans because of the lack of robust advice regarding vaccination. Much of vaccine preventable illness can in fact be prevented through the use of vaccines. Failure to vaccinate in my experience has resulted in a lot of loss of life and severe illness and other adverse clinical outcomes, all of which can be avoided with appropriate intelligent recommendations around the use of vaccines.
Mahoney: We touched earlier on the potential for a major bird flu outbreak, underscoring the need for timely and effective vaccine recommendations. How well equipped is ACIP, in your view, to respond to emerging threats of this nature and further, as the process for licensure of a vaccine takes several years, what steps have to be taken to prepare for a potential bird flu outbreak among humans?
Kotton: The CDC and FDA are obviously quite aware of the situation as regards the bird flu threat. CDC and ACIP can't make recommendations until a vaccine candidate has received either approval or emergency use authorization (EUA) by FDA. We became quite familiar with EUA during the pandemic and paid careful attention to its implications as to what we can and cannot recommend, and how we can progress beyond the EUA level. We have an influenza work group at the CDC with a whole host of experts with bird flu expertise at the ready. In the pandemic, by way of precedent, we turned on a dime as we didn't have a COVID-19 work group. In the influenza case we already have the work group, a convened group of experts to deploy against the novel viral threat, up and running. These people have been vetted and approved with all confidentiality forms and the like in place. We meet twice a month right now, or more often as needed, but we're ready to go and I would think that having gone through the pandemic, we could manage a similar real time response in the case of bird flu. With this said, it is presently unclear if the current administration would support efforts at CDC ACIP to respond in real time in the face of human-to-human transmission of a variant of current bird flu strains. There was understandably a lot of concern when FDA canceled an important meeting of VRBPAC (Vaccines and Related Biological Products Advisory Committee) which was to decide which influenza strains to select for vaccines for the coming year. It's unclear whether the administration would be supportive, and whether the newly reconstituted CDC ACIP could respond to bird flu and make vaccine recommendations on a timely or if need be emergency basis. I also have larger administration response and approval concerns as to whether FDA will be able to provide approval or EUA for a novel bird flu vaccine. Canada has a lot of work under way in this regard, so we are behind the curve, which is disturbing. I'm also worried that if we do have a severe bird flu human variant outbreak, there may be insufficient healthcare workers willing to step up in the way that made such a huge difference to success of our nationwide immunization efforts in the COVID 19 pandemic.
Mahoney: In the context of measles, you have emphasized the continued importance of routine childhood immunizations as well as adult boosters in many cases. How can ACIP and public health officials effectively address vaccine hesitancy and misinformation that may be leading to dangerously low levels of vaccination against highly contagious diseases?
Kotton: The CDC does some nice work, with great educational modules on the website, communicating the importance of vaccination and what ramifications are – risks like significant brain damage and even mortality – of not getting immunized against severe vaccine preventable measles. The challenge is how to get this vital information from the CDC into communities. My understanding of one of the major contributors to the measles outbreak in West Texas earlier this year is that a specific community, for religious and cultural reasons, does not vaccinate their children. That's a much bigger issue than I think CDC alone can take on, and this has been the case in other closed communities where there have been outbreaks of vaccine preventable syndromes. Whether those communities are willing to engage in informed scientific discussion of benefits versus risks of immunization is certainly an open question, but I believe CDC is ready, willing and able to support education and to go into communities of this nature and do what is needed to dispel doubt and misinformation. During the pandemic, for example, CDC created a bridge program to provide COVID vaccines for under vaccinated or unvaccinated persons, with the goal to provide immunologic equity, a powerful public health concept that no matter who you are or where you live, you would have fair and open access to COVID-19 vaccines. To increase immunologic equity more comprehensively and systematically requires community leadership engagement – mayors, other community leaders, teachers etc. – and perhaps in some cases religious leadership engagement, to effect behavioral change around vaccination acceptance, especially in crisis situations like outbreaks with high morbidity and mortality.
Mahoney: At the same time, a related serious concern from a global epidemiological perspective is the shutdown of surveillance of incoming measles and other viral contagion risks from other countries. Do you have any perspective on that problem?
Kotton: I am very concerned that as we shut down surveillance abroad, we are putting ourselves at grave risk for serious infections to occur in the United States. Earlier this year, for example, there was a significant Ebola outbreak in Africa; there's really no reason patients infected with Ebola during such outbreaks might not land say at the airport here in Boston and walk around and infect people with this high mortality risk disease. Interdicting global disease surveillance is thus a very dangerous situation and we are putting a lot of Americans at risk of potential harm.
Mahoney: Based on your experience, what specific policy recommendations would you offer to strengthen ACIP's role and effectiveness in the future and improve trust in CDC's vaccine choices and immunization recommendations? Speaking of influenza specifically, how does ACIP in general address the problem of misinformation spread through social media and otherwise, for example, in conjunction with the promotion of seasonal influenza vaccination?
Kotton: ACIP as an independent body gives recommendations to CDC but is reliant on CDC’s own funding, which as I noted has been insufficient regarding advertising campaigns. We’ve experienced a tremendous amount of influenza this year, with appreciable morbidity and mortality, but only about 46% of Americans have so far gotten a flu vaccine or about the same as last year. CDC was about to launch a robust influenza vaccine campaign but it was canceled in February. Similarly, only about 20% of Americans have had the updated COVID-19 vaccine. So, there's a lot of missed opportunities for disease prevention and I think a lot more campaigns and education are necessary, reaching out to various communities, schools, native reservations, and especially different racial communities because we know some populations are substantially under vaccinated and that is unfortunate and avoidable. At the same time, CDC has tried to provide honest and accurate scientific information with straightforward recommendations in various sections of the CDC website, some in plain language written for patient facing materials, and others written for clinicians. For a more systematic attempt at fighting misinformation, I'm not aware of any specific campaigns at the CDC other than trying to provide the right information to patients and their families as well as physicians.
Mahoney: What do you see as some of the foremost challenges of creating vaccine recommendations? You mentioned Ebola as a particularly scary example of public health challenges during a time of increased political polarization.
Kotton: There's definitely polarization in terms of vaccine uptake receptivity. It’s often said consumer preferences in this regard follow sort of a bell-shaped curve, but I would say it's actually a biphasic distribution. On one hand, there are people extremely pro-vaccine who can't get enough vaccines. At the other extreme are people wanting no vaccines, and then some people in the middle. It’s fair to say that the complexity of the vaccination schedule has significantly increased and it's hard to follow all of the recommendations. CDC has a very good app allowing clinicians to plug in a patient's information and understand all the vaccines they should get, and people can use the app themselves. The app provides all the vaccines indicated based on age, medical condition and other indicia, and the good news is with so many more vaccines now, we can prevent so many diseases it is a game changer.
In clinical practice, for example, I had seen a tremendous number of shingles cases. In 2021, ACIP voted to recommend the Shingrix vaccine for all immune compromised people, 19 years of age and over, or people who could become immune compromised. As a practicing clinician seeing patients who have about a 50% risk of developing shingles in their lifetime, including disseminated total body disease and encephalitis, I would routinely see one to two cases of brain damage per year. I no longer see these cases, which is amazing – cases which could be life threatening, or life compromising, of severe shingles with intense pain, or encephalitis with brain damage. To prevent those cases, with pretty rare exceptions, is wonderful. I love being put out of business. It is great to decrease preventable illness, hospital admissions, and conditions like long COVID. I recently read a report that we're seeing more long COVID in the state of Maine, which is devastating to affected individuals, their families and communities, and the workforce. As I think about vaccines and their role in society, if I am well vaccinated, I will protect myself against severe disease and hospitalization, but I’m also protecting my patients, my family and my community. I'm decreasing my healthcare costs by staying out of the hospital, rather than filling up the emergency room or taking the hospital bed of somebody else who needs it, simply because I didn't get vaccinated. Right now, if we return to measles, the more people who are vaccinated against measles, the more we will protect vulnerable people around us. Getting vaccinated is self-serving, but it's also a community service, and we don't think about that enough.
Mahoney: Your reference to the shingles vaccine is a great example of how a vaccine for one indication can have beneficial effects in others that are unexpected. In the case of the Shingrix vaccine in particular, we're getting some very interesting data now that show it can be protective against dementia.
Kotton: Indeed, that vaccine also potentially decreased risk of cardiac events, although it can often be hard in public health to ascertain for example what effects are directly from vaccination rather than that people more likely to have gotten the vaccine have a decreased cardiac risk profile for other reasons. So, there are certainly effects to tease out with this vaccine, but it does look like it is cost effective and as I’ve said, Shingrix has been transformative for a disease that was a common reason for hospital admissions and extreme suffering. That I and my current fellows now don't see shingles much is wonderful.
Mahoney: What are the key areas of focus in your mind for ACIP in the coming years, particularly in light of emerging infectious diseases, some of which we've discussed today, and evolving public health challenges?
Kotton: Well, it's hard to know what the evolving public health challenges will look like and what our mandates will be, so it's a bit beyond my capacity to guess. If I looked back a year and projected forward with no significant changes, we would have important new vaccines coming in the pipeline. For example, ACIP created a new CMV (cytomegalovirus) vaccine work group. There would be other work groups created and then potentially we would have more vaccines being brought forward preventing more diseases and that is a very good thing for the United States, for high income countries, for low-income countries, and for the world as a whole.
Mahoney: In closing, what do you think are the best methods to maintain ACIP’s scientific independence?
Kotton: ACIP has always been a very select group of physicians and scientists known for their expertise. I think keeping ACIP independent from the government is very important. In recent years, the government has had a more visible role in ACIP and in some cases may have been treading a little too closely on our turf. For instance, there was one meeting where we didn't have a quorum and so some HHS employees substituted for ACIP members so we could vote on new vaccines, but we're technically supposed to be separate from the government. We have very strict rules about who can and cannot vote in work groups, and if you work for FDA, HHS or CDC, you’re not supposed to be voting in ACIP meetings. Unfortunately, there's been blurring of that line in recent years. I’m convinced there's a lot of merit to a purely external group deciding on which vaccines are most suitable for use in the US. If the country had a better appreciation of ACIP’s role and the need for our independence, we would have more trust and faith in the whole system of getting vaccines to patients. The public needs to understand that we are an outside group of concerned individuals, not working for industry or the government, and the only “skin in the game” we have is trying to protect Americans against vaccine preventable illness and ensure public safety.
About the Author:
Tom Mahoney, a 2024 Senior Fellow at the Harvard Advanced Leadership Initiative, is focused on global venture philanthropy initiatives to catalyze investment in development of breakthrough vaccines, therapeutics and diagnostics for infectious diseases. A career investment banker, technology entrepreneur and asset management senior executive, Tom is a member of the Advisory Board of EdJen BioTech, LLC, a developer of novel viral vaccines, and Virufy, a respiratory disease diagnostics platform; a Founding Sponsor of the Harvard Alumni Entrepreneurs Accelerator; and a member of the Venture Board of the Harvard HealthLab Accelerators, the Massachusetts Consortium on Pathogen Readiness, and the Council on Foreign Relations.
This Q&A has been edited for length and clarity.