1. What is a vaccine
In the modern scientific environment, pattern searching and repeated trial and error are tools for human progress. There is evidence that Chinese people have used vaccination as early as 1000 AD. The Ayurvedic text of India also pointed out the use of vaccination. By the 1500s, Africa and Türkiye had also used vaccination. Before the advent of vaccines, pandemics and epidemics were the main causes of death in Homo sapiens.
Simply put, vaccines are weakened or dead forms of pathogenic microorganisms that can stimulate the immune system and produce antibodies against stronger versions of pathogens.
(1) The modern beginning
Modern Westerners are able to get vaccinated thanks to Edward Jenner, who in 1796 extracted pus from a milkmaid suffering from cowpox and infected eight year old James Phipps with the disease. Six weeks later, James recovered from cowpox, and Jenner later vaccinated the boy with smallpox, which has never been done before.
However, it was not until the 1840s that smallpox vaccination began to become popular.
(2) Second generation
The famous Louis Pasteur introduced the second generation vaccine in the 1880s. Jenner's breakthrough was due to the recognition that people who survived cowpox were immune to smallpox, while Pasteur, considered one of the fathers of the pathogen theory, was the first person to artificially weaken the disease and create vaccines.
(3) 1900s
Since the late 19th century, researchers have been working hard to develop vaccines for both humans and animals, attempting to produce and manufacture these vaccines in more realistic environments (whether for humans or animals). Over the years, researchers have explored various ways to achieve this goal, including chemically defined culture media, serum reducing culture media, etc., striving to find methods that can achieve greater effectiveness.
From a production perspective, if you want to achieve good results from vaccines, FBS has provided additional nutrition to produce this vaccine. It's not that people still won't continue researching synthetic compounds, but based on the history and efficacy of the past 30 years, FBS is still a clear ingredient in vaccine production
2. The Application of Serum in Vaccine Production
(1) History
In 1949, Enders, Thomas Hackwell, and Frederick Chapman Robbins reported in the journal Science on the in vitro culture of an animal virus called poliovirus (Cultivation of the Lansing Strain of Poliomyelitis Virus in Cultures of Various Human Embryonic Tissues). This is the first report on the growth of viruses in cell culture, which opened up a new field of research on animal viruses and laid the foundation for the production of vaccines using cell culture technology in the future. These three scientists were awarded the Nobel Prize in Physiology or Medicine in 1954 for their contributions.
In 1962, scientists P.B. Capstick, R.C. Telling, and others published a report in Nature on BHK cell suspension culture and its sensitivity to foot-and-mouth disease virus. At that time, the cell culture used Eagle's basic medium+10% bovine serum+10% TPB (pancreatic peptone phosphate broth/Cryptose Phosphate Broth).
In 1965, scientists such as R.C. TELLING published "Submerged Culture of Hamster Kidney Cells", which introduced the equipment and culture medium used for BHK-21 cell suspension culture.
At present, bovine serum has been widely used in large-scale cell culture. Due to its better cell culture effect compared to calf serum and its ability to approach fetal bovine serum, large-scale production enterprises such as vaccine production will prioritize economical and cell culture effective bovine serum. Fetal bovine serum is usually used for cells that require high culture conditions.
However, due to the fact that the price of adult bovine serum is much lower than that of newborn bovine serum, and there are precedents for the application of adult bovine serum in the early stages of vaccine industry development, antibody removed adult bovine serum is used in vaccine production in countries such as India and South America, such as in the field of animal vaccines for foot-and-mouth disease. Adult bovine serum can not only be used in cell culture, but also plays an important role in virus culture. In 2010, L. Robinson et al. published a paper on the research of BHK-21 cell foot-and-mouth disease vaccine titled 'Foot and Mouth Disease Virus Exhibits an Altered Tropism in the Presence of Specific Immunoglobins', The article "Enabling Productive Infection and Killing of Dendritic Cells" mentions the use of GMEM+1% bovine serum virus culture method.
(2) Function
Animal serum is a key raw material for the production of viral cell matrix vaccines. Viruses need to grow and proliferate within animal cells, which requires culturing and expanding cells with serum, then proliferating the virus using cultured cells, and finally producing vaccines through various downstream processes.
FBS is used as an additive in growth media and cultivation is crucial for research purposes (as well as cell proliferation). The efficacy of FBS in vaccine development has been repeatedly demonstrated. When using concentrations between 2-10%, FBS can efficiently promote in vitro cell growth through its nutrients, hormones, growth and adhesion factors. FBS also has lower levels of growth inhibitory factors (such as antibodies), which can be used to buffer environmental changes (such as pH changes).
Therefore, many people prepare vaccines using fetal bovine serum as an additive to the growth medium.
FBS is often used as part of growth media, and researchers then use this medium to study, cultivate, and harvest vaccines. FBS itself does not exist in vaccine products; However, its macromolecular proteins are used as nutrients, while other growth factors can promote rapid proliferation of the required cells.