The fact that vaccines have made it possible to protect the population against a series of diseases can give rise to the perception that the risk of vaccination outweighs the benefitsThe recent very sad case of a 6-year-old boy who contracted diphtheria and had not been vaccinated triggered a spate of articles in the press on the subject of immunisation and the debate on the rights of parents to reject vaccinations for their children.
In such situations, the immense value of vaccines is usually immediately recognised, but at the same time the need to continue vaccinating is still unjustifiably called into question.
Paradoxically, one of the motives for questioning the need for vaccination is the very effectiveness of our immunisation programmes: the fact that vaccines have made it possible to protect the population against a series of diseases can give rise to the perception that the risk of vaccination outweighs the benefits, because very few or no cases of the disease are being detected. Another erroneous belief is that people who are not vaccinated are protected by the immunised status of those who are. And to all of this, of course, we must add the cases of people who reject vaccination on the basis of unproven claims that vaccines have damaging effects.
Unfortunately, in many parts of the world are far from having achieved adequate coverageThe reality is that if immunisation is to achieve the desired results, we have to continue vaccinating people with all the appropriate vaccines, both old and new, according to the guidelines laid down by experts in public health. The ultimate goal is to maintain optimum levels of coverage in the community because, otherwise, an increase in the number of susceptible individuals would increase the risk of disease outbreaks.
And we must take this logic even further, because our approach to the problem should be global. Unfortunately, in many parts of the world, and precisely those which—due to their high disease burden—could benefit most from vaccinations, are far from having achieved adequate coverage for a number of reasons. As a result, millions of lives are lost that could have been saved by vaccination. This is certainly one of the immediate and indispensable objectives at this time.
But much more can be done. The major lines of innovation in this field include, but are not limited to, the following:
1) New vaccine development. One of the most recent examples demonstrating the interest of developing a new vaccine as quickly as possible is the case of the Ebola virus. The groundbreaking model being used for the clinical development of Ebola vaccines will not only produce a vaccine, it will also provide lessons that may well prove useful in other diseases.
2) Improving existing vaccines. Innovation can sometimes be as simple as improving an existing product, giving rise to a product that can be called "new"—if you like—a product with features similar to its precursor that has an added advantage. For example, one of the two companies with products on the market that protect against infection with the human papillomavirus (HPV) has recently produced an improved version of the vaccine, a formulation that acts not only against the two most common oncogenic types of the virus that were targeted by the original product, but also offers protection against a wider spectrum of cancer-causing HPV strains.
Innovation can sometimes be as simple as improving an existing product, giving rise to a product that can be called "new"—if you like—a product with features similar to its precursor that has an added advantage3) Facilitating the administration of vaccines. Vaccines are usually administered parenterally by injection, but administration using a microneedle patch rather than the conventional needle and syringe would not only be easier and more pleasant for the patient, but could also be more efficient. This delivery system is currently being tested for the measles vaccine, among others.
4) Using existing vaccines in different ways. Reducing the number of doses of a vaccine and spacing them out more conveniently over the immunisation schedule is an efficient way to improve coverage, because the number of visits is reduced.
5) Increasing access to vaccines for those who most need them. The task of public health systems could be simplified by a number of different strategies, including the introduction of new production methods to reduce costs and the emergence of companies willing to produce vaccine formulations that simplify or dispense with the need for a cold chain system.
The range of possible developments in the field of immunisation and vaccines is vast and every new generation can be improved through the incorporation of additional advantages, such as an enhanced safety profile.
It is a pity that, rather than being able to concentrate all our efforts on innovation in this field, we are still obliged to divert resources and energy to "defending" the importance of vaccinationVaccines are one of the most cost-effective public health interventions we have. They are not only useful in the prevention and control of many potentially fatal diseases, they also contribute greatly to our quality of life. It is a pity that, rather than being able to concentrate all our efforts on innovation in this field, we are still obliged to divert resources and energy to "defending" the importance of vaccination, the benefits of which should by this time be obvious.
What is needed, therefore, is a dynamic approach: while continuing to vaccinate and ensuring that the population is properly protected, we should at the same time anticipate future needs through the development of new tools and health interventions.