Vaccinology

Vaccines are among the most effective public health interventions currently available. Smallpox has been eradicated and polio has almost disappeared worldwide through global vaccine campaigns. Most of the viral and bacterial infections that traditionally affected children have been drastically reduced thanks to national immunization programs in developed countries. Together with antibiotics and clean water, vaccines have increased life expectancy in both high- and low-income countries by eliminating many of the diseases that historically killed millions. It has been estimated that vaccines will have saved ~25 million deaths over 10 yr from 2010 to 2020, which is equivalent to five lives saved per minute. In terms of cost-effectiveness, it is estimated that $1 invested in vaccination results in a $10–44 healthcare saving.

In spite of the success of vaccination in preventing disease and its cost-effectiveness, several challenges remain such as increasing the diversity of the target populations by developing vaccines efficient in pregnant women who will protect their babies at early life, and in the elderly displaying a less efficient immune system to be primed.

Besides preventing infectious diseases, a few examples of already available vaccines preventing virus-induced cancers, such as liver cancer due to the hepatitis B virus or cervical cancers due to papilloma viruses, pave the way for further development of anti-cancer vaccines. Large-scale analysis of immune responses in humans, combined with progress in identifying key antigens that induce effective immunity, will enable the development of more effective vaccines in the near future.