Viral vector vaccines against COVID-19: how they work
What is a viral vector?
Viral vector vaccines use a version of a mild virus to safely deliver instructions in the form of genetic code to our body cells.
These instructions enable your body to produce a harmless piece of the coronavirus, the ‘spike’ protein.
This type of vaccine makes your immune system familiar with the spike protein, so it can kill the coronavirus off in the event of infection and prevent the disease.
Viral vectors used in vaccines do not affect or interact with your DNA.
What happens in your body when you get a viral vector vaccine
- after the injection, the adenovirus carrying the instructions for creating spike proteins enters your cells
- your body creates spike proteins
- your immune system detects the foreign proteins and produces antibodies and immune cells to attack them
- your body gets rid of the adenovirus and the genetic information quickly
- if you are later infected with coronavirus, your immune system will detect the spike proteins and destroy the virus
- you won't get sick
An important advantage
The tough protein coat of the adenovirus helps protect the DNA genetic instructions inside.
As a result, viral vector vaccines don't have to stay frozen at ultralow temperatures and can last a few months when kept at normal fridge temperature (2-8 °C).