Two centuries of vaccination: historical and conceptual approach and future perspectives

Abstract

Over the past two centuries, vaccines have been critical for the prevention of infectious diseases and are considered milestones in the medical and public health history. The World Health Organization estimates that vaccination currently prevents approximately 3.5–5 million deaths annually, attributed to diseases such as diphtheria, tetanus, pertussis, influenza, and measles. Vaccination has been instrumental in eradicating important pathogens, including the smallpox virus and wild poliovirus types 2 and 3. This narrative review offers a detailed journey through the history and advancements in vaccinology, tailored for healthcare workers. It traces pivotal milestones, beginning with the variolation practices in the early 17th century, the development of the first smallpox vaccine, and the continuous evolution and innovation in vaccine development up to the present day. We also briefly review immunological principles underlying vaccination, as well as the main vaccine types, with a special mention of the recently introduced mRNA vaccine technology. Additionally, we discuss the broad benefits of vaccines, including their role in reducing morbidity and mortality, and in fostering socioeconomic development in communities. Finally, we address the issue of vaccine hesitancy and discuss effective strategies to promote vaccine acceptance. Research, collaboration, and the widespread acceptance and use of vaccines are imperative for the continued success of vaccination programs in controlling and ultimately eradicating infectious diseases.

An Overview of Current Vacccines for the Prophylaxis of Bacterical Infections

“…New attenuation methods include the use of recombinant DNA technology to achieve direct mutations or elimination of genes encoding important virulence factors. Compared to other types of vaccines, the distribution and storage of live attenuated vaccines requires a "cold chain"' to maintain their viability (7,8). The use of live attenuated vaccines is contraindicated in persons with congenital or acquired immunodeficiencies, in persons receiving immunosuppressive therapy, and in pregnant women, as they may experience complications due to over-proliferation of the vaccine strain and disease outbreak.…”

“…For this reason, these vaccines are administered in several doses. They are more stable than live vaccines and less demanding to handle in terms of the cold chain (7,8).…”

“…Today, different types of antimicrobial vaccines are used for the prophylaxis of infectious diseases: whole-cell vaccines (inactivated or live attenuated vaccines); subunit vaccines (recombinant, conjugated polysaccharide, polysaccharide, and VLP vaccines); toxoid vaccines; nucleic acid vaccines (mRNA and DNA vaccines) and viral vector vaccines (Table 1) (7,8).…”

Current Progress in Vaccines against Merkel Cell Carcinoma: A Narrative Review and Update

“…Vaccines ideally work in the prevention of infections (e.g., polio, smallpox, diphtheria, tuberculosis), when a person is administered the vaccine before being infected. In the case of malignancies, however, the situation is more complex, since only a minor fraction of malignancies are associated with infectious agents [1]. However, de Martel et al [2] recently reported that, for 2018, about 2.2 million infection-attributable cancer cases were diagnosed worldwide, corresponding to an infection-attributable age-standardized incidence rate of 25 cases per 100,000 person-years [2].…”

“…Cancers that are caused by viral infection include cervical, liver, and head and neck malignancies, and their prevention by vaccines plays a crucial role in reducing the risk of cancer development. Consequently, vaccines have been developed and approved, for example, that are capable of preventing hepatitis B virus or human papilloma virus (HPV) infection and thus protecting against the development of the aforementioned virus-related cancers [1]. In this setting, when cancer has already developed, it is possible to identify targets for malignant cells that can aid in distinguishing tumor cells from healthy cells [3][4][5][6][7][8][9][10][11][12][13].…”