This is the time when governments are planning different waves of Covid 19 vaccination (SARS-CoV-2 virus) to immunize their populations, some simple questions came to my mind…. as my motto is to never pretend we know everything, I will start easy with “What is a vaccination?” and “What is the origin of the vaccination?” … Then, we can look at the next ones “Are there different types of a vaccines?” , “How long does it take to develop a new vaccine?”, “Are there any side effects?”, “What about COVID 19?”, “How long are we protected after a vaccination? “… I am pretty sure this post will open the door to more questions but this is a start …. I traveled the web over the past few week and filtered a lot of different sources to come up with the below – Enjoy!
What is a vaccination?

https://m.ufhealth.org/vaccines-immunizations-overview
If I am simplifying a lot what I remember from my old immunology classes (1997-98)…, a vaccination is the injection of a small part of a virus (or bacteria) in the body that triggers an immune response against it (via antibody activation) – and the result of this response is the protection against the virus. This is very simplified… this is what I remember but this is the concept !
What is the origin of vaccination?
The terms “vaccine/vaccination” are coming from Variolae vaccinae (smallpox of the cow) and this is an English scientist, Edward Jenner who developed in 1878 the concept of vaccine. He created the first vaccine against the smallpox (variolae). And thanks to Pasteur (I am proud, he is french) who then proposed to extend the name “vaccine” to all further inoculations.
Are there different types of a vaccines?
If you are good with the above definitions … that is now becoming complex… there are not 1, 2 or 3 type of vaccines but I found 7 types online…
The best video I found is the one below from the University of Chicago… it is clear and simple –
The first type of vaccine is the attenuated (live virus) one – it uses the weakened form of the virus (examples are measles, mumps, rubella (MMR) and varicella (chickenpox)). They cannot be given to people with weak immune systems
Then, there are the inactivated (killed virus) are safer for people that have weak immune systems but need multiple shots (Examples are Flu and polio vaccines)
Subunit vaccines contain part of virus/bacteria – they tend to have side effects in comparison to the 2 first we mentioned. The whooping cough (pertussis) vaccine is an example.
There are other types of vaccines like conjugate and toxoid vaccines that contain a toxin or chemical made by the bacteria or virus. Examples are the diphtheria and tetanus vaccines.
New Types are being developed like mRNA and Vector-based vaccines – It uses our cells to produce antigens against the pathogens. Example of mRNA vaccine are the COVID 19 ones.
And there is always some other innovative ways to produce new sort of vaccines… like research, it is never ending.
How long does it take to develop a new vaccine?
To develop a vaccine is taking time but testing a vaccine is also take a lot of time… that can take up to several years to develop a vaccine. Based on the history, this is fascinating how fast some companies came up to develop a vaccine against COVID 19 in less than a year… an interesting video below will give you some additional inputs.
Are there any common side effects?
It depends on the vaccine in question but the most common side effects include fever, pain around the injection site, and muscle aches.
If you are allergic, you also have to mention it, before being vaccinated as there maybe some ingredients in the vaccine that you can be allergic to…
I will not talk about COVID 19 side effects here… It is too early to provide some serious data.
What about COVID 19 vaccine?
I found a fantastic video from AsapSCIENCE that explains perfectly (with smart drawings everything) you need to know about COVID 19 ! Honestly, this is greatly explained with simple words…
For how long are we protected after a vaccination?
If we are talking about the flu vaccine, it generally only lasts through one flu season, which is about six months long…. you will then tell me then : For how for long will the COVID 19 vaccine protect us?
I read a lot of different info online…. a minimum of nine months? to three to four years?…. (based on animal data on other coronavirus vaccines).
Some others are saying that it’s too early to say anything about it as scientists need to collect more data from vaccine trials—some of which will simply take longer to collect.
According to the clinical trials data, Pfizer’s vaccine, can protect partially as early as 12 days after the first dose and that protection can last for at least two months…. there is a need of second dose to get full potential of the vaccine… but for how long it will last? .