Table of contents
- Introduction
- Where do vaccines come from?
- How many types of vaccines are there?
- How are vaccines made?
- How do you make vaccines in bioreactors?
- Conclusion
- Sources
Introduction
No time before in the history of mankind after the Spanish Flu, have humans needed vaccines more than now. The world is standing at the turning point of its history, with every day a new challenge for the people to survive. The hospitals are overwhelmed, and the health infrastructure is being tested to its limit. This is not just the case with third world countries, but the developed world is also struggling. Now, the whole world has pinned their hope on the vaccines to save the day and bring a respite for mankind that is gasping for another breath. But how much do we know about vaccines, how are they produced and how many types of vaccines are there? Should we trust vaccines? All these questions will be answered in this blog post.
Vaccines are usually stored in small vials, cooled and waiting to be administered.
Where do vaccines come from?
The idea of vaccines is not new, it is believed that the Chinese were the first to use dry pus to cure diseases long before Edward Jenner formally made vaccines into a miracle of science. Edward Jenner, a controversial medical practitioner, self-published a book that changed the world in 1798. An Inquiry into the Cowpox was a book that illustrated how people should shield themselves from smallpox, a disease that killed up to one in every 12 people and left survivors scarred for life. Inoculation with cowpox, a virus that affects animals, was the cure. This was the start of a revolutionary process known today as "vaccination," which comes from the Latin word "Vacca," which means "cow.'' The world then used his method to protect themselves from all kinds of diseases ranging from Spanish flu to measles and mumps. Today there is a vaccine for almost every type of disease. Although we no longer use the brutal methods Edward Jenner used for his vaccine discovery, yet, the principle is the same.
How many types of vaccines are there?
Although the underlying principle of the vaccine remains the same whatever type of vaccine is used, however, based on what technology we use, vaccines can be divided into six main groups:
- Inactivated vaccines
- Live-attenuated vaccines
- Messenger RNA (mRNA) vaccines
- Subunit, recombinant, polysaccharide, and conjugate vaccines
- Toxoid vaccines
- Viral vector vaccines
Almost all vaccines are developed against one particular section of a virus, the Spike protein of SARS-CoV-2, for example, that helps the virus enter into a cell, thus the most conspicuous part of the virus. As for covid, for example, four types of vaccines have been developed i.e., the inactivated vaccine, subunit vaccine, mRNA vaccine and viral vector vaccine. There is hope that more vaccines will enter into circulation by the end of 2021.
Interested in more details about vaccines for SARS-CoV-2? One of our previous blog posts dives into the topic in a bit more detail, so we suggest you give it a read.
A type of vaccine is the mRNA vaccine. Specific COVID-19 vaccines, which are mRNA vaccines are the ones from Pfizer and Moderna.
How are vaccines made?
Vaccine development is a tricky business, it may take up to 26 months before a viable vaccine makes its way to the market. Also, the process varies with the type of vaccine as well. The process is often tedious and many times the scientist has to go back to the drawing board once they identify a flaw in the process. But most of the vaccine development starts with the pathogen itself.
We will take the time tested live attenuated vaccine example here. The process starts with the identification of pathogens. The scientist then uses various methods to make the pathogen weaker, making it less susceptible to cause disease. Once a vaccine is developed it is tested on animal models to see if it is safe for humans. That is followed by trials on small and large human groups. Only if the vaccine is safe and has more chances of eliciting a viable immune response, it is marketed and used for mass vaccination.
How do you make vaccines in bioreactors?
Bioreactors are fascinating machines as they provide optimum conditions for the bioprocess to occur. As vaccine production is already a very complex process and needs perfect calibrations, bioreactors are the main tool for the magic to happen.
The process starts with the pathogen mass growth. If it is a virus then it needs cells to grow in and those cells are also grown in the bioreactors. The conditions are maintained at an optimum value and the cells are subsequently infected with the pathogen. These virus or pathogen-infected cells are then left until the viral load is large enough to start the second process, the inactivation of the virus/pathogen.
In this step, the pathogen is treated with a chemical such as formaldehyde or heat-inactivated in case of killed vaccine until it is no longer capable of producing the disease but is still viable to incite the immune system. These killed or attenuated pathogens are then injected into test animals like rats and primates to see if they are at an optimum level.
The whole process is centred around the bioreactors that are the starting and endpoint of the whole design.
Vaccine production starts and ends in a bioreactor vessel.
Conclusion
Vaccine production is a difficult and time-consuming process that requires a lot of work. It has become more defined and a lot more optimized since its beginnings in the 18th century, not just the production, but the administration to patients as well.
Different pathogens require different approaches to treatment, but there are 6 main types of vaccines. They differ in the type of molecule that gets injected into the patient’s body.
The production process requires very delicate and precise conditions, so using good-quality bioreactors to have perfect control over these conditions is a must (if you are a vaccine producer, we advise you to check out our bioreactor arsenal, as we think our software and hardware solutions are the best fit for vaccine production).
So next time you get a shot of a vaccine, be it for the coronavirus or any other, appreciate the hard work and countless monitoring that goes into making it possible.
Sources
1. Upstream process development for viral vaccines | Batavia Biosciences (https://www.bataviabiosciences.com/viral-vaccines/process-development/upstream-process-development/)
2. Vaccines from a Reactor (https://www.mpg.de/9093521/W003_Material_Technic_054-061.pdf)
3. How are vaccines developed? (https://www.who.int/news-room/feature-stories/detail/how-are-vaccines-developed)
4. There are four types of COVID-19 vaccines: here’s how they work | Gavi, the Vaccine Alliance (https://www.gavi.org/vaccineswork/there-are-four-types-covid-19-vaccines-heres-how-they-work)
