Interview with Teresa Aguado: The Value of Vaccines

Teresa Aguado, who received her Ph.D. in immunology from the University of Barcelona, has accumulated over two decades of experience at the World Health Organisation (WHO), where for 14 years she was Coordinator of vaccine product research and development in the Initiative for Vaccine Research. During this time, she made a significant contribution to the creation of several public-private partnerships for vaccine research and development. Earlier in her career, Dr Aguado spent eleven years working on basic research into autoimmune diseases and immune tolerance. In her current position, she serves as a consultant for ISGlobal in projects related to vaccines and immunisation.

Your doctorate is in immunology and you have dedicated your whole career to vaccines. What is it that attracts you to this field?

In part I think it is my basic training: the combination of my knowledge of immunology and of pharmaceutical formulation. Once I began working in this field, it became a passion for me because I see vaccines as one of the most cost-effective public health interventions available. They also have great potential to contribute to ending child mortality, and their use can be expanded to other age groups and to address other challenges: new diseases (new vaccines) and new applications (therapeutic vaccines and vaccines against  "unconventional" antigens).

We usually associate vaccines with childhood, but your most recent professional projects focus on vaccines for adults and elderly people. Why is vaccination important in adulthood and later life?

Vaccination beyond childhood can have multiple benefits, including finishing the task we have begun. This can be achieved a) by administering booster doses and b) through the use of vaccines more adapted to administration in adults.

The immune system, like the other organs and systems in our body, is susceptible to ageing. Correct vaccination of adults, starting in adolescence, can enhance quality-of-life and promote healthy ageing. It is possible that in the near future we will increasingly be talking about a "lifelong immunisation programme".

It would also seem likely that the opportunity provided by the contact with health care personnel at the time of vaccination could offer a valuable entry point for other public health interventions, tailored to the specific needs of each population and each environment.  

Will vaccines be as cost-effective in older people, who have fewer years of life ahead of them?

In principle, they will. However, the considerations are different from those we take into account in the case of immunisation in childhood, when the primary aim—although not the only one—is to fight infant mortality.  What we are trying to do in adults is to improve the patients' quality-of-life and, at the same time, minimise the cost of treating disease and hospitalisation. The answers we need will come from cost-effectiveness studies and epidemiological studies that correctly document the existing situation.  

There are groups who are critical of vaccines. What are the greatest misconceptions that people have about immunisation?

Like any other drug or biological product, vaccines are a wonderful tool but they are not perfect. Under certain circumstances, they can have some side effects that are considered acceptable by the health authorities, regulatory agencies, and the general public. In each case we must evaluate the risk/benefit ratio. As infectious diseases are gradually eliminated and their incidence declines, the population's tolerance for adverse effects also diminishes. A good example of this is the pertussis vaccine, which comes in two types: a whole cell vaccine and a subunit vaccine.

In the majority of developed countries, the whole cell vaccine has been replaced by the subunit vaccine, which is much less reactogenic (causes fewer adverse effects) but possibly also somewhat less immunogenic (does not provide such good immunity). As the number of cases of pertussis in developed countries has declined significantly, the risk/benefit ratio is such that the subunit vaccine is preferred. In developing countries, however, the incidence of pertussis is greater, thereby justifying the use of the whole cell vaccine, which being more reactogenic is also more immunogenic. If these differences in the choice of products for different populations based on the risk/benefit analysis are not properly explained to health professionals (including the people administering the vaccines) and the general population, misunderstandings can arise that damage national immunisation programmes.

In general, there is communications problem. There should be an ongoing effort to explain in a comprehensive, simple and completely transparent way—in different terms depending on the audience—the risk-benefit profiles of vaccines. 

What is currently the biggest obstacle to universal immunisation: funding, access, or a lack of understanding of the power of immunisation?

As you say, there are many obstacles. Lack of funding is a significant factor, but not the only one by far. Among the determining factors, we could highlight a few: a) having the necessary infrastructure to distribute and administer vaccines properly; b) having a sufficient amount of the vaccine available where and when it is needed; c) being able to sustain the programme after one or more vaccines have been introduced; d) the erroneous perception of the risk/benefit profile.

Key players in the world of global health—including the WHO, UNICEF, and the Bill & Melinda Gates Foundation—have joined forces to promote global immunisation through the Decade of Vaccines Collaboration, whose secretariat is coordinated by ISGlobal together with PATH and the Sabin Vaccine Institute. What do you think of this project?

I think this is one of the best things that can happen—that different "partners" find common ground and work together to achieve beneficial goals without having to sacrifice their independence or mode of action. The Decade of Vaccines Collaboration and its Global Vaccine Action Plan (GVAP) have established a series of objectives and produced a roadmap for the next decade. To a great extent, this document gives the deciding voice—and the responsibility—to the countries themselves, since they are ultimately the decision-makers for implementing any measures that are adopted.

What role do you think ISGlobal can play in vaccine research and implementation in both children and adults?

ISGlobal is already making a key contribution to global health through its involvement in the areas of tropical diseases and maternal and infant healthcare. It does this work through centres of excellence and by collaborating in strategic locations in different continents. However, its leadership, together with the Sabin Vaccine Institute, in the coordination of the Decade of Vaccines document—the new global roadmap for all activities related to vaccines and immunisation in this decade—has demonstrated their capabilities in this area.  ISGlobal has positioned itself as an institution with the capacity to undertake immunisation projects with a new vision and real knowledge of the needs of the countries most in need of the new vaccines.