New Vaccine Technologies and Development

- Overview

Ever since the development of the first vaccine more than 200 years ago, vaccinations have greatly decreased the burden of infectious diseases worldwide, famously leading to the eradication of small pox and allowing the restriction of diseases such as polio, tetanus, diphtheria, and measles. A multitude of research efforts focuses on the improvement of established and the discovery of new vaccines such as the HPV (human papilloma virus) vaccine in 2006, COVID-19 vaccine in 2021. 

However, radical changes in the density, age distribution and traveling habits of the population worldwide as well as the changing climate favor the emergence of old and new pathogens that bear the risk of becoming pandemic threats. 

- New Vaccine Technologies to Combat Outbreak Situations

Vaccines are one of the most effective medical tools ever created, saving more lives than any other medical or public health innovation. Prior to COVID-19 (in 2020) they were estimated to prevent 2-3 million deaths a year. They do this by using an active ingredient, usually one that is inherently biological, to safely mimic a pathogen in order to trigger an immune response. However, for these active ingredients to be most effective and safe, other equally critical ingredients are needed.

In recent years, the rapid spread of severe infections such as HIV, SARS, Ebola, Zika and COVID have highlighted the dire need for global preparedness for pandemics, which necessitates the extremely rapid development and comprehensive distribution of vaccines against potentially previously unknown pathogens. What is more, the emergence of antibiotic resistant bacteria calls for new approaches to prevent infections. 

Given these changes, established methods for the identification of new vaccine candidates are no longer sufficient to ensure global protection. Hence, new vaccine technologies able to achieve rapid development as well as large scale production are of pivotal importance. 

- Emerging Concepts and Technologies in Vaccine Development

Although vaccination has been successful in substantially reducing or eliminating the threat of disease caused by pathogens, there are still some known diseases and emerging pathogens against which developing successful vaccines is inherently difficult. In addition, developing vaccines for those who are immunocompromised and with other pre-existing conditions remains a major challenge. 

In addition to traditional inactivated or attenuated live vaccines, viral vector vaccines, and subunit vaccines, emerging non-viral vaccine technologies, such as virus-like particle and nanoparticle vaccines, DNA/RNA vaccines, and rational vaccine design, offer solutions to existing Challenging innovative approaches to vaccine development. 

They also significantly advance our understanding of vaccine immunology and could guide future vaccine development for many diseases, including rapidly emerging infectious diseases such as COVID-19, as well as diseases not traditionally addressed by vaccination, such as cancer and pharmaceuticals abuse.

- Immunology and Vaccine Development

Immunization is a cornerstone of public health policy, and it is clearly cost-effective to protect children's health. Although it can be argued that immunology has so far contributed little to vaccine development, as most of the vaccines we use today have been developed and tested empirically, it is clear that the development of new vaccines against hard-to-target pathogens, for which we urgently need Gain a better understanding of protective immunity. 

Furthermore, the recognition of the great potential and challenges of vaccines in controlling disease outbreaks and protecting aging populations, together with the availability of a range of new technologies, makes it an opportune time for immunologists to engage in the design of the next generation of powerful immunogens. 

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- What Ingredients Go into a Vaccine?

Vaccines contain tiny fragments of the disease-causing organism or the blueprints for making the tiny fragments. They also contain other ingredients to keep the vaccine safe and effective. These latter ingredients are included in most vaccines and have been used for decades in billions of doses of vaccine. 

Vaccines contain active ingredients that trigger an immune response to viruses, bacteria and other pathogens. Each vaccine component serves a specific purpose, and each ingredient is tested in the manufacturing process. All ingredients are tested for safety. 

The main ingredient in most vaccines is water. But added to this and the active ingredients are inactive ingredients, or “excipients”, which either boost the immune response to the vaccine or act as preservatives and stabilisers. These are usually included in very small quantities with some found naturally in our bloodstream. Even so, all excipients are subject to rigorous assessment before they can be included in vaccines, to ensure the substances are safe in the quantities used, with systems in place to monitor their safety on an ongoing basis.

- Regulation and Testing of Vaccines

Vaccines are one of the most significant achievements of science and public health. As a result of successful vaccination programs and campaigns, many vaccine-preventable diseases are now uncommon in the United States. Vaccines for prevention of infectious diseases are regulated by the U.S. Food and Drug Administration (FDA) and the legal framework for regulation is derived from Section 351 of the Public Health Service Act and from certain sections of the federal Food, Drug, and Cosmetic Act (FD&C Act). 

The FD&C Act defines drugs, in part, by their intended use as “articles intended for use in the diagnosis, cure, mitigation, treatment, or prevention of disease.” Thus, vaccines are a unique class of pharmaceutical products that meet the statutory definition of both a drug and biological product. 

Prophylactic vaccines differ from many other drugs and biologicals primarily in how they are administered to a large population, in particular, young healthy people to prevent rather than treat disease, their mechanism of action, and their risk/benefit profile. Although subject to the same regulations as other biological products, vaccines are inherently more difficult to develop, characterize, and manufacture than most pharmaceutical products. 
 

- COVID-19 Vaccine Development and Implications for Future Medicines

Building on deep scientific knowledge gained from decades of experience with viruses such as MERS, SARS, influenza, HIV and Hepatitis C, biopharmaceutical companies have made unprecedented progress in advancing treatments and vaccines to help fight COVID-19. At this time, three vaccines and several treatments have received emergency use authorizations (EUAs) from the U.S. Food and Drug Administration (FDA) with one treatment receiving FDA approval. Additional candidates under investigation have also shown promise. 

Behind this rapid progress are advances in technology and understanding about the nature of the immune system, which have allowed us to more rapidly respond to the current pandemic compared to previous episodes. For instance, it took just a few months to have the first vaccine candidates to test against the coronavirus, compared to 20 months to have a vaccine ready to test in SARS patients a decade ago. Moreover, all of the vaccines that have received EUAs so far rely on groundbreaking platform technology meaning once a genetic target is identified from a new infectious agent, the platform can be used to quickly create prototype vaccines to move into preclinical and clinical testing.