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Johns Hopkins Bloomberg School of Public Health


Keyword: vaccines

By Lois Privor-Dumm, Nina M. Martin, PhD, and Prar Vasudevan

Young children and older adults are both at higher risk for potentially devastating and debilitating diseases, many of which are vaccine-preventable. Countries prioritize and routinely immunize infants, yet the same cannot be said for older adults, variably defined as 50, 60, 65, or 70+ years of age, with or without risk factors. There is no simple explanation of why countries looking at very similar data come to very different conclusions. Even experts and the global health community are divided on the role of adult immunization. As a result, a large portion of countries have failed to address vaccine-preventable diseases like influenza, pneumococcal disease, and herpes zoster (shingles),  which affect this fast-growing demographic.

AMRO PAHO Vaccination Image

Photo Courtesy of AMRO/PAHO

Why haven’t countries prioritized vaccinating adults?

Some reasons countries don’t prioritize vaccinating older adults include budgetary pressures and competing priorities. Vaccines also may be suboptimal for the elderly population. Countries may be unaware of the disease burden. As adults live longer and lead more productive lives, understanding opportunities for the prevention of premature death, disability, or serious economic consequences becomes increasingly important.

What is the state of adult immunization globally?

As a starting point, the International Vaccine Access Center (IVAC) was commissioned by the World Health Organization to conduct a preliminary literature review and qualitative interviews to characterize the state of adult immunization globally, including in low- and middle-income countries. The findings demonstrated a significant burden of disease and a need for a robust life course approach to be taken by both countries and the global community.

Although evidence gaps exist, there is a major opportunity to address vaccine-preventable disease—through immunization and other preventive measures—in the older population. However, there is a significant need for global technical consensus and more unified global guidance, as well as action at both the country and global level. The vaccine community can be alone in taking action: Diverse voices, representing the healthy aging community, must also be sitting at the table.

Photo by Gavi

Photo courtesy of Gavi

Reviewing policy across 30 countries to build a policy roadmap  

To build political priority, IVAC is first addressing basic criteria to develop a roadmap for policy decisions and increased uptake. To support the effort to build a roadmap. This research, which includes both a desk review and in-country interviews, will contribute to:

  1. Establishing a summary resource of key data describing the state of adult vaccine policies and uptake around the world,
  2. Highlighting key factors that influence and guide the introduction and use of adult vaccines, and
  3. Developing a framework to assess country archetypes for adult immunization that could help inform data needs or approaches that support policy making, access, and uptake.

A global platform is needed and IVAC’s adult immunization project is poised to fill this need. There are many ongoing individual and regional efforts to fill gaps, but there is no coordinated, global platform that promotes awareness, facilitates technical consensus, provides leadership, and collaborates and coordinates with other key stakeholders. In addition to the creation of a database and framework, IVAC is convening a group of independent experts with specialties in infectious disease, immunization, economics, and healthy aging to create the International Council on Adult Immunization. This council will review the research, determine a technical consensus, and lead international collaboration around adult immunization.

AMRO PAHO vaccination woman

Photo courtesy of AMRO/PAHO

For questions, please contact

Nina Kate Swati selfie

Nina Martin, Kate O'Brien, and Swati Sudarsan, IVAC


Listen to the full episode: Public Health United Episode 52: Kate O’Brien on Vaccines and Social Justice


What is PHU?

Public Health United, Inc. (PHU) is a non-profit organization that improves science communication through podcasts, outreach, and public engagement training for scientists. Dr. Nina Martin is PHU’s Chief Executive and host of their weekly podcast, with each episode featuring a different public health science expert with stories and insights on science communication.  At IVAC, Nina does research on adult vaccines on the Policy and Advocacy Communications Team.

PHU recently featured Executive Director of IVAC, Kate O’Brien. The podcast was co-hosted by Swati Sudarsan, who works on pneumonia advocacy and global coordination on IVAC’s Policy and Advocacy Communications Team.

Who is Dr. Kate O’Brien?

Kate is a sitting member of the Strategic Advisory Group of Experts (SAGE), which advises the World Health Organization on global vaccine policy, and serves on the Gavi Board representing the Technical and Research constituency. She is a senior advisor at the Center for American Indian Health, and of course, a beloved professor in the Department of International Health at the Johns Hopkins Bloomberg School of Public Health.

Can't listen, but want the info?

During this episode, Kate tells us a little about who she is and why we should care about vaccines. A pediatrician by training, she explains that her passion for health equity was fostered during her time in Haiti, where she saw first-hand the consequences of vaccine-preventable disease on children. Here she developed “a deep desire to contribute to the vaccine world.” Because of this experience, Kate believes that vaccines are fundamentally a social justice issue. The current reality that a poorer person is less likely to be vaccinated than someone from a higher income setting is what she calls “a moral failing” of our society.

Part of the reason this happens is because there needs to be greater financing for vaccines. Kate is working to advance scientific discussions by helping quantify the “full public health value of vaccines.” For example, vaccines not only prevent disease in an immunized child, but they can protect the people around them, can help families avert the costs of hospitalization from disease, and can even help mitigate an emerging crisis – antibiotic resistance.  Kate is also working to make vaccines more accessible to families in novel ways. For example, new evidence has demonstrated that fewer doses of pneumococcal conjugate vaccine (PCV) may be effective in areas where pneumonia transmission is virtually eliminated and thus be able to save government’s billions of dollars, an important benefit to global vaccine policy and implementation.

Kate’s passion for vaccines extends beyond the office and to her family dining table. This holiday season, take Kate’s advice and talk to your family about their vaccination status. For more on Kate’s take, click here to listen or download the episode.


Related Episode Links:

·       Full list of PHU podcasts

·       Join the online discussion on Twitter with IVAC and PHU.

·       Kate’s profile at JHSPH

·       SAGE at WHO (expert panel on immunization)

·       Kate’s World Health Organization (WHO) Profile

·       Kate is quoted in this November 2017 National Geographic feature, “Here’s Why Vaccines Are So Crucial”

·       Journal article in Vaccine (Oct 2017): ‘Estimating full public health value of vaccines”

·       Gavi: The Vaccine Alliance




Your companion on the red-eye from Dulles airport to Geneva is a two inch-thick Yellow Book—478 pages of previous meeting notes, disease eradication plans, reviews of evidence, references, and more related to the meeting of WHO’s Strategic Advisory Group of Experts (SAGE)—including at least seven global policy questions you will need to make a decision about. All this in 30 hours of meetings over three days.

Feeling fuzzy getting off your flight? Grab a double expresso as you are head over to WHO HQ on Avenue Appia. Outcomes of these meetings will inform WHO’s Director-General and lead to new recommendations from WHO for all countries on the best ways to ensure vaccines improve health and save lives for as many people as possible.

Welcome to SAGE!

IVAC's Delegation at SAGE 2017 

WHO Meeting Room


From October 17-19, three faculty members from the International Vaccine Access Center (IVAC), of the Johns Hopkins Bloomberg School of Public Health (JHSPH), provided technical expertise and leadership at the annual SAGE meeting, an advisory body formed in 1999 to provide guidance on immunizations to the WHO.

IVAC’s delegation included Director of Epidemiology Bill Moss, Director of Science Maria Deloria Knoll, and IVAC Executive Director Kate O’Brien. The meeting, held in the August Room where WHO’s 34-member Executive Board meets, was attended by about 200 people and included presentations from nine Working Groups. SAGE Working Groups delve in to key immunization-related questions of interest to policymakers around the world.  

Maria and Kate at SAGE

The Executive Board’s elevated screen helps viewers sitting on multiple tiers follow presentations. Maria’s purple sweater helped people locate her in the immense room.


How did IVAC members at SAGE support policy-making for WHO?

Measles and Rubella

Dr. Moss, who also serves as a Professor in the Departments of Epidemiology, International Health, and Molecular Microbiology and Immunology (MMI) at JHSPH, has been a member of SAGE’s Measles and Rubella Working Group since 2011. Dr. Moss presented evidence supporting a recommendation that people living with HIV do not need to be re-vaccinated against measles if they were not infected with HIV at the time of their measles vaccination in young childhood. This policy has implications on the estimated 34.5 million adults living with HIV infection and on the achievement of measles elimination goals.


Dr. O’Brien, who is a Professor in both Departments of International Health and Epidemiology at JHSPH, has served as a SAGE member since 2012 and has participated in multiple Working Groups over the past four years. This year Dr. O’Brien chaired the SAGE Working Group on rabies vaccines and rabies immunoglobulins, which are antibodies that recognize and bind to the rabies virus to destroy it. Sidebar Dr. O’Brien’s analysis of rabies vaccine policy became personally relevant during a holiday in Mexico: a bat flew into her son Jack’s face and sent them on a complicated journey to locate rabies immune globulin and vaccine (fortunately, they found them both and Jack remains healthy!).  

Pneumococcal conjugate vaccine

Dr. O’Brien also co-led the Pneumococcal Conjugate Vaccines Working Group (more about this below). During this meeting, Dr. Knoll, who serves as an Associate Scientist in the JHSPH Department of International Health, presented on a review IVAC authored of over 200 studies assessing the effect of both of WHO’s recommended dosing schedules on vaccine-type disease, or the strains of pneumococcus included in the 10- and 13-valent conjugate vaccines.

Recommendations to WHO Director-General

Dr. O’Brien and the other 14 members of SAGE—each representing a different institution and country—considered the evidence and made formal recommendations to WHO. For example, based on the evidence presented, SAGE concluded that both WHO-recommended PCV schedules have a substantial impact on reducing vaccine-type disease. All evidence presented during the meeting is available in the Yellow Book.


How SAGE gathered evidence to optimize the impact of pneumococcal conjugate vaccines

Starting in January, the pneumococcal conjugate vaccines (PCV) working group, led by SAGE members Dr. O’Brien and Dr. Andrew Pollard of the University of Oxford, reviewed extensive evidence on PCV impact. One of the main sources of evidence was the PCV Review of Impact Evidence (PRIME) Systematic Review, an effort co-led by IVAC with partners including the US CDC, WHO, the University College of London, and Agence de Médecine Préventive. Over the past two years, the PRIME group reviewed studies to assess differences in disease, immunogenicity, and carriage impact by PCV schedule and product, as well as evidence of immunogenicity of catch up immunization. This systematic review served as an update to a previous review conducted by IVAC, which compared impact of different schedules in the context of PCV7 use and served as an important evidence base for previous SAGE WHO PCV recommendations. 

Among the PRIME review’s findings on PCV schedules:

Immunogenicity: A 3-dose primary series induces a greater immune response compared to a 2-dose primary series. However, in a 3-dose schedule, the third dose is more immunogenic when given as a booster (2+1) for most serotypes. It is important to note that greater immunogenicity may not necessarily mean better protection from disease.

Nasopharyngeal Carriage: Both schedules showed an impact on overall vaccine serotype carriage (product specific vaccine-type).

Invasive Pneumococcal Disease: Both schedules showed impact on overall vaccine-type invasive disease.  For serotype 1, the 2+1 schedule showed clear evidence of impact from a substantial body of evidence; for the 3+0 schedule although some impact was seen the data were more limited.  

WHO’s recommendations related to dosing schedule, catch up vaccination, and product usage will be published in a PCV Position Paper in 2018. If there are opportunities to improve impact, countries using pneumococcal vaccines may consider update their schedule and product choices.

In the meantime, we’re clearing off our bookshelf space for the next onslaught of documents… SAGE will re-convene April 17-19, 2018 – see you there!


For more information, see the resources below:

By Dr. Kate O’Brien, Executive Director, International Vaccine Access Center (IVAC)

Yesterday we were saddened to learn that former President George H.W. Bush was hospitalized with pneumonia. While the majority of people affected by pneumonia in the US are adults, around the world each day this condition claims the lives of an estimated 2,500 children under age 5. 

Back in September, when Secretary Hillary Clinton suspended her campaign due to pneumonia, I wrote about the under-recognized toll this illness takes on communities around the world. As we find ourselves on the eve of a new presidential administration, it’s imperative to repeat the message and remind policymakers of the common needs of families around the world.

Pneumonia, an infection of the lungs, is exceedingly common around the world, with an estimated 450 million cases annually. In the US, we have ready access to trained physicians with the know-how and equipment to make a diagnosis and, when necessary, we have antibiotics and oxygen therapy to treat illness. These interventions have been proven effective, and the vast majority of people who contract pneumonia in the US make a full recovery.

Sadly, this is not true everywhere. In impoverished countries, timely, appropriate, and affordable treatment is often not available, especially for young children whose course of illness can take a downturn very quickly. In parts of Africa and Asia resources are scarce, and HIV infections, crowding, and indoor air pollution are prevalent and put people at risk. The prevention measures we take for granted, such as vaccines and hand washing, are too often not available. The price of pneumonia in these countries is higher infection rates, more illness and, sadly, more deaths, especially in children younger than 5 years of age.

Over the past 15 years, public health professionals and policymakers have been able to assure significant progress. Vaccines to prevent the deadliest causes of pneumonia are rapidly being deployed in countries in most need—thanks to Gavi, the Vaccine Alliance, and country governments. Gavi, to which the US government is a major contributor, makes it possible for low-income countries to buy and deploy tens of millions of doses of life-saving vaccines, including against pneumonia, to millions of children. As more children have access to vaccines and medicine to prevent and treat pneumonia, we see less disease, fewer lives lost, more families climbing out of poverty and fewer families thrown back into the downward cycle of poverty which is otherwise incurred simply by trying to get medical care to save their child’s life.

Yet, much work remains. More than 900,000 young children still lose their lives to pneumonia each year. These children need access to the same tools as our own children to prevent, diagnose, and treat this common illness.

More than anything else, we must put pneumonia on our collective radar as a global health problem that requires attention—not just when there’s a new media headline. How many people know that globally pneumonia is the leading cause of death for children under 5 years of age? Pneumonia is so common that it’s nearly invisible.

Can this change? Absolutely. We have the opportunity to raise the profile of this illness and reveal just how pervasive it is. We hope President Bush makes a speedy and full recovery. Meanwhile we continue to advocate for adequate resources for families, governments, and communities everywhere to prevent and treat this illness. What improves the lives of people in countries around the world is also good for the US. It’s simple: Hopeful, healthy communities create a world where we all thrive, including here at home. 


Kate O’Brien, MD, MPH, is the Executive Director of the International Vaccine Access Center and Professor at the Johns Hopkins Bloomberg School of Public Health. She is a pediatric infectious disease physician, epidemiologist and vaccinologist.

In celebration of World Immunization Week, we asked some of our staff to reflect on their careers and why immunization is a critical tool in public health.


Here’s what inspires them:

What was the moment you realized you wanted to work in the immunization/vaccines field?
“It clicked for me when I was taking care of kids who had Hib meningitis during the late 1980's right after the vaccine was starting to be used in the United States.” – Kate O’Brien, Executive Director

“While serving as a Peace Corps Volunteer in West Africa, I worked with the local Ministry of Health's National Immunization Days for Polio.  I spent a week traveling out to remote villages vaccinating children and providing Vitamin A supplements to prevent Polio.” – Matt Coles, Senior Program & Contract Analyst

“After completing my pediatric training I worked in Addis Ababa, Ethiopia as a pediatrician for two years and saw many children die of vaccine-preventable diseases, most notably measles and meningitis.” – Bill Moss, Deputy Director

What do you find rewarding about working in global health? In immunization/vaccines?
"Knowing how much of an impact vaccines can have on every family.  Many families will never know the devastation of these preventable illnesses and knowing I contributed to that, even in a small way is HUGE for me.” – Lois Privor-Dumm, Director of Policy, Advocacy & Communications

“Being a positive part of a global community.” – Diane Coraggio, Research Associate

“Working in global health has allowed me to understand the root causes of poverty and disease that plague the majority of the world, and do so inequitably, and has provided me with the confidence and skills I need to contribute to changing the current situation and addressing those root causes.” – Olivia Cohen, Research Associate

“Immunization programs target healthy people and aim to keep them healthy. What better way contribute to public health?” – Kyla Hayford, Research Associate

What are you most proud of in your work at IVAC or in immunization/vaccines?
“I am always proud when the pediatricians and public health experts we have worked with advocate for change and speak up for needed interventions in effective ways - I love seeing a little bit of training and empowerment turn into something much bigger and better than we would have ever thought of!” – Lois Privor-Dumm, Director of Policy, Advocacy & Communications.

“I'm most proud of the impact our work has----it has tangibly and meaningfully contributed to actually moving the needle on getting vaccines to the people and places where they are most needed.” – Kate O’Brien, Executive Director

“It's especially rewarding when governments and policymakers use our work to make decisions around vaccines. “– Brian Wahl, PhD Candidate

What is something about immunization/vaccines that you wish more people knew?          
“Vaccines are by far one of the most cost-effective public health solutions!” – Diane Coraggio, Research Associate

“Immunizations are the best buy out there-----there isn't anything that does a better job of preserving health and enhancing life.” – Kate O’Brien, Executive Director

What do you find most challenging about your vaccine/immunization work?         
“There is so much to do and so little time!  The vaccine world is a complex space and this field needs the best, the brightest, and all of our efforts to make accelerated progress.” – Kate O’Brien, Executive Director 

“One of the most challenging things about successful vaccine work is that it can undermine itself. The disease goes away and people no longer understand how important vaccines are and they played in reducing the disease burden.” – Bill Moss, Deputy Director

What do think is the biggest challenge to closing the immunization gap? 
“I think the focus needs to be more on the hard to reach with an understanding that where the greatest burden is (often where health systems are weakest) is truly the priority.  There have been some examples of successful programs, countries, communities and the global health community need to focus on all aspects of strengthening immunization programs - both on the demand and supply side.” – Lois Privor-Dumm, Director of Policy, Advocacy & Communications.

“Delivery, delivery, delivery and optimizing the ways in which we use the vaccines we have.” – Kate O’Brien, Executive Director 

“Reaching populations in areas of continuous conflict zones, refugee camps, and increasingly in areas of recent natural disasters.” – Olivia Cohen, Research Associate

“Improving accountability and governance in many developing countries and integrating immunization with other primary healthcare services will help close the gap.” – Brian Wahl, PhD Candidate