
COVID-19 vaccines train your immune system using a harmless form of the virus, COVID-19. To do this, vaccines get your immune system to respond without actually causing you to get ill with COVID-19. But how each COVID-19 vaccine does this is different, so let’s look into that!
We’ve drawn this info from a great article by the British Society of Immunology, you can read the full article if you’re interested here!
COVID-19 Viral Vector / Adenovirus Vaccines
Which vaccines?
The Oxford/AstraZeneca, the J&J, CanSino, & Sputnik V (Gamaleya) vaccines

How does it work?
This type of vaccine uses a harmless virus shell that is not COVID-19 (known as the viral vector) to deliver COVID-19 genetic material. When a person gets this vaccine, our cells use the genetic material to produce a particular kind of ‘viral protein’ (kind of like our body accidentally pushing the panic button), which calls our immune system into action and triggers a response. This response trains our immune system, so your body knows what to do when the real COVID comes.
COVID-19 Genetic / mRNA Vaccines
Which vaccines?
The Moderna & Pfizer/BioNTech COVID-19 vaccines, as well as the CureVac & Inova pharmaceuticals.
How does it work?
This type of vaccine also contains a part of genetic material of the COVID-19 virus. The genetic material, it carries is RNA in the case of Moderna, whilst the Pfizer/BioNTech vaccine, carries a kind of viral protein.
When you get vaccinated with this kind of vaccine, your body’s cells use the genetic material from the vaccines to make more of the special kind of viral alarm protein, which your immune system notices and responds to (that ‘false alarm’ again). This response builds up your immune system’s memory, so your body knows how to fight off COVID-19 when the real thing shows up.
Are genetic/mRNA vaccines new?
Yes and no. mRNA vaccines are newly available for us as the public to use, but researchers have been working on them for a very long time. Researchers have been studying and working on mRNA vaccines for decades, as the technique was discovered in 1987 by Robert Malone.
Are genetic/mRNA vaccines safe?
The genetic/mRNA vaccine has been widely politicized long before the first COVID-19 vaccine was available. When you just look at the research, they are incredibly safe. Many people worry that genetic vaccines will change our genetic code, but that simply not true. These vaccines use mRNA which never enters the nucleus of the cell where our DNA (genetic material) is stored, so it cannot change or influence our genes (Tang et al., 2022)
COVID-19 Inactivated Vaccines
Which vaccines?
Sinovac, Sinopharm, & the Bharat Biotech vaccines, as well as Shifa-Pharmed & the Chinese Academy of Medical Sciences vaccines.
Your yearly flu (influenza) jab uses this method as well.
How does it work?
This type of vaccine uses a killed COVID-19 virus, which is recognised by the immune system and triggers a response, but doesn’t cause the COVID-19 illness. This response builds immune memory, so your body can fight off the real and very much alive COVID-19 in future.
COVID-19 Attenuated Vaccines
Which vaccines?
The Codagenix vaccine, but It’s currently only in trials.
The oral polio vaccine uses this method.
How does it work?
This type of vaccine uses a weakened version of the COVID-19 virus, which is recognised by the immune system and triggers a response, but it doesn’t cause a person to actually get ill with COVID-19. This response builds your immune system’s memory, so your body can fight off the real strong COVID-19 virus in future.
COVID-19 Protein Vaccines
Which vaccines?
The Novavax vaccine, & Sanifi/GSK vaccine.
The Hepatitis B vaccine also uses this method.
How does it work?
This type of vaccine uses the proteins from the COVID-19 virus, which are recognised by the immune system and trigger a response. This response builds immune memory, so your body can fight off COVID-19 in future.
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