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Understanding how Vaccines Work

Jane is planning to book her COVID-19 vaccination. She calls her doctor to find out some

information about the different types of vaccines…

Jane: Good morning, Dr White. Can you please give me some information about COVID-19

vaccines and how they work?

Dr White: Good morning Jane. Of course, I can! First of all, you need understand the basics

of how our immune system works. Basically, when any virus enters your body, it will attach

itself to one of your cells and inject its DNA or RNA into it - this contains instructions for

what the cell has to make. So, it will tell your cells to make more copies of the same virus.

Jane: OK… So, how can my body defend itself?

Dr White: Well, our immune system naturally attacks any virus, or bacteria which does not

belong in our body. Although, it takes a few days for it to act. So, to give our immune system

a helping hand, scientists have developed vaccines.

Jane: How many types of vaccine exist?

Dr White: There are various types of vaccines, but the latest are the mRNA ones.

Jane: Are they safe?

Dr White: The biggest misunderstanding about this technology is that the mRNA in the

vaccine can enter our cells and change our very own DNA, but that is not true - mRNA is

very fragile and only survives a few hours in our bodies, just long enough to produce viral

proteins which kickstart our bodies immune response. After a while, your body will break

down all of the vaccines mRNA.

Jane: OK… and what happens with the traditional vaccines?

Dr White: More traditional vaccines use weakened versions of the actual virus. This also

triggers an immune response, but it can give you mild symptoms.

Jane: Thank you very much for explaining, Dr. White. I feel much more confident, and I’m

looking forward to receiving my vaccine soon!

Cups of Coffee
Understanding how Vaccines Work


Phrasal verb
Example sentence
To come around

To become conscious again after an illness or an operation

One hour after the operation, she started to come around.

To shake something off

To get rid of an illness

I really hope I can shake this cold off before the weekend.

To pass out

To become unconscious for a short period of time.

When the ball hit her on the head, she passed out.

To pick something up

To start to suffer from something

She picked up the cold when she was- on holiday.

To come down with something

To start to suffer symptoms of an illness.

I think I’m starting to come down with the flu.

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