How does a COVID-19 vaccine work in the body?

Biology/Immunity Vaccines

A: Vaccines show your body how to fight a virus without actually making you sick from the virus.

Here is how this works (inspired by this fun explainer)

🦠 SARS-CoV-2 (aka the virus that causes COVID-19) is a round little thing with spikes coming out of it.

⛏️ The spikes help the virus stick to our cells. This happens more in some parts of the body than others (like our lungs). This is how the virus gets into our usually smart cells, who are really good at not letting things from outside our body in.

🧬 The Pfizer and Moderna vaccines use mRNA (this is a little message in a bottle) that tells the cells to make that pesky little spike protein. The Johnson and Johnson vaccine uses the spike protein’s DNA (the recipe that makes the virus what it is), goes into the cells, then makes mRNA that tells the cells to make the spike protein.

💉 Once someone gets the vaccine, the cells right around where you get the vaccine (“watch cells”) find the mRNA or DNA. They are looking out for it, kind of like a hall monitor looking out for any problems! Once they find it, they know it isn’t supposed to be there. So these hall monitors eat up the mRNA or DNA and start making the spike protein.

🎭 Once the hall monitors (“watch cells”) make the spike protein, they can show it to your immune system. Once they do that, it is destroyed. Think of this as a message that is destroyed after someone important sees it!

👮♀️ Then the hall monitors gets busy. They make the spike protein, but NOT the whole virus. They also let the other cells know that these are NOT your spike proteins and you need to get rid of them.

⚙️ Then the immune system (B cells, T cells, and a bunch of other stuff) gets to work. Your B cells come and set “traps” or antibodies for the spike proteins. They will do this even after the spike protein disappears. Some of your T cells help the B cells make more antibodies. Others make sure that the spike protein isn’t in any other cell. If it finds another one on a cell, it will destroy it and the cell!

And that is it!

🤒 When this starts, there is a lot happening right in your arm and throughout your body. So you might feel a little sick. But this is just your body practicing how it would respond to the real coronavirus by fighting off and developing the skills to fight the spike protein. It does NOT mean you have COVID-19.

💪 It DOES mean that you will be ready to take out SARS-CoV-2 if and when it tries to get into your cells.

We hope this little explanation helps both kids and adults!

Stay Safe. Stay Sane.

With Love,
Those Nerdy Girls

For kids: Fun video on viruses and the immune system with Dr. Ashley Ritter and a super smart kiddo

For adults: Dr. James Conway explains COVID-19 Vaccine Development (an oldie but goodie!)

For everyone, a dramatic interpretation and a fun TikTok on how the mRNA vaccine works @hotvickkrishna

Image credit for how this works NPR: https://n.pr/3jGCN6f

Link to Original FB Post