Immunity and Vaccine-Preventable Diseases

Vaccines are among the most effective tools in medicine. Today there are vaccines to help prevent more than 25 potentially debilitating and deadly human diseases, including COVID-19, an outbreak of which was officially declared a pandemic by the World Health Organization (WHO) on March 11, 2020. Vaccines have had a profound impact on public health. Between the 1970s and 2020s, infant mortality declined by 40 percent, thanks to global vaccination efforts. An estimated 154 million deaths were prevented in that same span of time, which, according to WHO, is the equivalent of six lives saved per minute per year.

Historical Developments

The story of vaccines begins with early rudimentary and courageous approaches to disease prevention, among them variolation, inoculation using infectious smallpox material. As this practice spread westward, eventually reaching Europe, it gained popularity and in the 18th century inspired the invention of the world’s first vaccine. Targeted against smallpox, this invention sparked a wave of scientific curiosity and ultimately led to a shift from passive acceptance of disease to proactive prevention. From its earliest days to the first COVID-19 vaccines, in 2020, the history of vaccine development is a story of human ingenuity and perseverance.

The Age of Immunological Mastery

Today innovative vaccine technologies—arising from the integration of genetic engineering, artificial intelligence, and nanoparticle delivery systems—are enabling accelerated vaccine development and responses to disease outbreaks. The rapid generation of mRNA vaccines during the COVID-19 pandemic is an example of this technological triumph. As work continues on next-generation vaccines, researchers have set their sights on tackling some of the world’s most elusive diseases, such as Zika, and on facilitating advances in precision medicine, in which vaccines are designed not only to prevent infectious disease but also to fight cancer, autoimmune disorders, and other conditions.