[author: Joy Key]

For centuries, humans have sought ways to protect from deadly diseases. The practice of intentionally exposing healthy people to smallpox, a practice known as variolation, likely began as early as 200 BCE. This practice of variolation or inoculation traveled from China to the West over several hundred years eventually arriving in the New World by the early 1700s. George Washington mandated the procedure for the Continental Army, and many historians contend that the practice contributed to the Army’s success during the Revolutionary War.

Vaccines have played a pivotal role in eradicating and controlling numerous deadly diseases, saving millions of lives worldwide. From the groundbreaking work of Edward Jenner to the cutting-edge mRNA technology used in the COVID-19 vaccines, the history of vaccine development is a remarkable story of scientific perseverance, innovation, and triumph over formidable challenges.

In 1796, Edward Jenner, an English physician, made a revolutionary discovery that laid the foundation for the modern vaccine era. Jenner observed that milkmaids who had previously contracted a milder disease known as cowpox were immune to the deadly smallpox virus. He conducted an experiment by inoculating a young boy with cowpox matter and later exposed him to smallpox, confirming his immunity. This groundbreaking work led to the development of the world’s first vaccine against smallpox.

Building on Jenner’s work, the smallpox vaccine became widely adopted, and a global effort to eradicate the disease was launched by the World Health Organization (WHO) in 1967. After decades of intensive vaccination campaigns and surveillance, the last known case of smallpox was reported in 1977 in Somalia. In 1980, the WHO officially declared smallpox eradicated, marking a historic triumph for public health and vaccine science.

Throughout the 19th and 20th centuries, advances in immunology and microbiology paved the way for the development of vaccines against various infectious diseases. Louis Pasteur’s work on attenuated [weakened live germ] vaccines, the discovery of viruses, and the understanding of immune system mechanisms all contributed to the creation of vaccines for diseases like rabies, cholera, typhoid, and influenza.

In the mid-20th century, the polio epidemic swept across the United States, leaving thousands of children paralyzed or dead. The development of the polio vaccine by Jonas Salk in 1955 and Albert Sabin in 1961 marked a turning point in the fight against this devastating disease. The March of Dimes, a nonprofit organization founded by President Franklin D. Roosevelt, played a crucial role in funding and promoting polio vaccine research, demonstrating the power of public-private partnerships in advancing scientific progress.

In the 1970s and 1980s, significant advancements in recombinant DNA technology were made, enabling the production of vaccines using genetic engineering techniques. This allowed for the development of vaccines against diseases like hepatitis B and the human papillomavirus (HPV). Additionally, conjugate vaccines, which combine bacterial polysaccharides with carrier proteins, revolutionized the prevention of bacterial infections, like Haemophilus influenzae type b (Hib) and pneumococcal diseases.

The COVID-19 pandemic highlighted the importance of vaccine development like never before. In an unprecedented global effort, scientists leveraged cutting-edge technologies, including mRNA and viral vector platforms, to develop vaccines against SARS-CoV-2 in record time. The rapid development and deployment of these vaccines demonstrated the power of modern vaccine science and international collaboration in addressing global health crises.

The future of vaccine development as well as the potential uses of mRNA technology are bright. mRNA technology, or messenger RNA technology, is a cutting-edge approach in biotechnology and medicine that involves the use of synthetic messenger RNA (mRNA) molecules. These mRNA molecules act as instructions for cells to produce specific proteins.

According to a review published in Nature Reviews Drug Discovery, mRNA vaccines can be designed to encode tumor-associated antigens, which can stimulate the immune system to recognize and attack cancer cells. This approach, known as cancer immunotherapy, aims to harness the body's own immune defenses to combat malignant cells.

Furthermore, mRNA-based therapies can also be used to deliver therapeutic proteins or gene-editing tools directly into cancer cells, potentially enhancing the efficacy of cancer treatments. A study, published in Genome Research, demonstrated the successful delivery of CRISPR-Cas9 gene-editing components via mRNA, enabling targeted gene editing in various cell types, including cancer cells.

The versatility of mRNA technology extends beyond cancer treatment and has potential applications in addressing various other diseases. One promising application is the production of therapeutic proteins for genetic disorders or autoimmune diseases. For example, mRNA-based therapies could be used to deliver enzymes or other proteins to replace defective or missing proteins in genetic disorders like cystic fibrosis or hemophilia.

One of the key advantages of mRNA technology is the relative ease and rapidity with which mRNA vaccines and therapies can be designed and manufactured compared to traditional methods. The mRNA sequence can be quickly synthesized and modified based on the target antigen or therapeutic protein, enabling a faster response to emerging diseases or evolving therapeutic needs. Additionally, mRNA is non-infectious and non-integrating, meaning it does not integrate into the host genome, making it safer than some other gene therapy approaches that rely on viral vectors or genome integration. This feature reduces the risk of insertional mutagenesis [creation of DNA mutations] and potential long-term adverse effects.

The history of vaccine development is a testament to the resilience of the human spirit and the transformative power of science. From Jenner's pioneering work to the remarkable achievements in eradicating smallpox and combating polio, vaccines have saved countless lives and alleviated immense suffering. As we continue to face new and emerging infectious diseases, the lessons learned from this remarkable journey will guide us in developing innovative solutions to protect global health and well-being.