Vaccines 101
We are all waiting for a Covid-19 vaccine. There are high expectations on the timing and distribution of such a vaccine. This short blog is a primer based on my recent learnings. Hope it will help you navigate all the information to correctly set your expectations.
Immunity is the ability of our body to recognize a germ and rapidly create immunity cells that release antibodies. The antibodies neutralize the invader and mark it for disposal. The immune army disbands when all the invaders have been eliminated.
This operation needs to take place rapidly (within a day) for the body to be asymptomatic or mildly symptomatic. When a new germ is encountered the body is not able to do this quickly and the germ can enter our cells, replicate and disrupt normal body functions.
Once the body has successfully eliminated a germ, the long-lasting impact is that it recognizes the germ when it appears next and can react rapidly to remove it within a day.
A vaccine is a controlled mechanism to trick the immune system into memorizing the germ signature. Traditionally a weakened or dead germ is injected so that our immune system can learn the signature and be ready when the real threat is seen.
Some germs (like smallpox, measles) have kept the same signature during our lifetime whereas the flu changes its signature every year.
In summary, to develop a traditional vaccine the steps are as follows:
Further Reading/References
RNA Vaccine, Immunity & Vaccines Explained, History of Vaccines
Immunity is the ability of our body to recognize a germ and rapidly create immunity cells that release antibodies. The antibodies neutralize the invader and mark it for disposal. The immune army disbands when all the invaders have been eliminated.
This operation needs to take place rapidly (within a day) for the body to be asymptomatic or mildly symptomatic. When a new germ is encountered the body is not able to do this quickly and the germ can enter our cells, replicate and disrupt normal body functions.
Once the body has successfully eliminated a germ, the long-lasting impact is that it recognizes the germ when it appears next and can react rapidly to remove it within a day.
A vaccine is a controlled mechanism to trick the immune system into memorizing the germ signature. Traditionally a weakened or dead germ is injected so that our immune system can learn the signature and be ready when the real threat is seen.
Some germs (like smallpox, measles) have kept the same signature during our lifetime whereas the flu changes its signature every year.
In summary, to develop a traditional vaccine the steps are as follows:
- Inject a subject with a weakened Covid-19 virus.
- Measure the reaction of the body.
- How many antibodies were created?
- How long did it take?
- Measure the effectiveness of the memory
- I do not know exactly how this is done, but logically...
- Inject the same subject with a stronger virus
- Measure reaction
- Repeat till satisfied
It would seem significant that we have therapeutics in hand to treat the subjects being given these test dosages. This appears to be another challenge in developing the vaccine rapidly.
There is an alternate method being pursued to create a Covid-19 vaccine. It is called the RNA vaccine. Such a vaccine has never been produced before, but conceptually has the advantage of being simple to manufacture.
Instead of targeting the entire germ, the RNA vaccine targets just one of the proteins required by the germ. For Covid-19 this is the protein that produces the infamous spike structure that we have seen. These spikes are responsible for binding the virus to our cells. Teaching the immune system to recognize this protein essentially achieves the same result as the traditional vaccine. However, its biggest challenge is distribution. The RNA vaccine only lasts for a couple of days even under super refrigeration.
A successful vaccine will need to have the following characteristics.
There is an alternate method being pursued to create a Covid-19 vaccine. It is called the RNA vaccine. Such a vaccine has never been produced before, but conceptually has the advantage of being simple to manufacture.
Instead of targeting the entire germ, the RNA vaccine targets just one of the proteins required by the germ. For Covid-19 this is the protein that produces the infamous spike structure that we have seen. These spikes are responsible for binding the virus to our cells. Teaching the immune system to recognize this protein essentially achieves the same result as the traditional vaccine. However, its biggest challenge is distribution. The RNA vaccine only lasts for a couple of days even under super refrigeration.
A successful vaccine will need to have the following characteristics.
- Simple/easy manufacturing process
- Low dosage
- Easy to distribute
Further Reading/References
RNA Vaccine, Immunity & Vaccines Explained, History of Vaccines
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