How are vaccines made?
An image of a large family sitting around the Thanksgiving dinner table. Mom, at the head of the table, is talking
Mother: I’m so glad we can all be together for Thanksgiving this year. Emily, we are especially happy to finally meet you. Sam has been gushing about you non-stop since you two started dating.
A smiling image of a young adult man (his son Sam) and his girlfriend (Emily)
Sam You finally have a doctor in the family, Mom! [laughs] Emily is almost done with medical school. He worked at the city’s vaccine clinic as his residency.
Image of mom smiling and talking
Mother. How wonderful! I just got my flu shot last week. I just wish I could convince Sam’s dad to do the same.
At the other end of the table, the figure of Dad is chatting
Dad: I’m sure you’re doing a good job, Emily. I’m just not convinced that vaccines are safe. How do they even come up with those things?
Image of Emily talking
Emily: I completely understand your concern, Mr. Rose. But much work is being done to make vaccines safe and effective. I can tell you a little about how they are made if you are interested. I don’t want to bore everyone. [laughs]
Image of everyone sitting at the table (except Emily) nodding and smiling
Dad: I’d love to hear from an expert source, Emily, and we’ve got a lot of turkey to go through here. [laughs] Please go ahead.
Step 1: Target selection
Emily: Well, first, scientists choose which disease-causing virus or bacteria to target with a vaccine.
Not serious enough
(these words must be one-to-one to match the VO)
Some viruses are not good targets because of interactions with the immune system. Others are too rare or do not cause serious enough disease to require a vaccine.
Image of a grown woman (Aunt Lucy) chatting at a table
Aunt Lucy. Isn’t there an HIV vaccine for that? Due to weather affecting the immune system?
Head shot of Emily
Circle the HIV and draw around it
Emily exactly. Although scientists are working on a vaccine against HIV. HIV is just not an easy target.
Step 2: Exploratory phase
Once a vaccine target is selected, the exploratory phase begins.
An image of a laboratory filled with a diverse group of scientists bent over microscopes
In this phase, researchers study how the virus or bacteria affects the immune system.
Image of Emily talking
A visual representation of the process of the training body of the simulated invader to protect against viruses/bacteria
The goal is to create a “mimetic invader” that teaches our body how to fend off the virus or bacteria. That way our immune system knows what to do when it encounters the real thing.
Step 3: Preclinical testing
Once the vaccine is finally developed, preclinical trials can begin.
A series of images: first a petri dish, then a mathematical equation, then a white mouse
At this stage, the vaccine is tested in several different ways that do not involve humans.
An image of a syringe/needle with a red X
Unfortunately, not many vaccines make it past preclinical testing because they don’t activate the immune system as well as they should.
Sam speaks as he puts more food on his plate
Sam If the vaccine does show potential, what happens next?
Step 4: FDA approval for clinical testing
Emily: The next step is to get approval for clinical testing from the FDA. This happens in three stages.
A diverse group of people lined up to receive a vaccine from a woman in a lab coat.
During the first phase of a clinical trial, small groups of people receive an experimental vaccine.
A larger, more diverse group of people lined up to receive a vaccine from the same lab-coated woman
During the second phase, the study is expanded to include people who have things in common (such as age and health) with the people for whom the vaccine is intended.
An even larger diverse group of people lined up to receive a vaccine from the same lab-coated woman
During the third phase, the vaccine is given to thousands of people to make sure it is safe and effective.
A little boy looks up while eating his food
Little boy. How are they sure the vaccine will work for everyone?
Image of Emily talking
Emily: Well, clinical trials try to include many different types of people to make sure the vaccine works well for everyone without dangerous side effects.
Step 5: Production and distribution
Vaccines leave production areas and are shipped and then reach doctor’s offices, pharmacies, public health facilities
Once a vaccine is finally approved, that’s when it goes into mass production and is distributed to doctors’ offices, pharmacies and public health clinics across the country.
Talking image of dad
Dad: That’s the part that worries me. How do we know a vaccine is safe when it has never been used before?
Checklist image with the words “safe” and “effective” disabled
Emily: I hear you, and I think it’s only natural to be anxious about something new. But vaccines are based on years and years of research, and a vaccine is never approved by the FDA until it is proven to be safe and effective.
The father figure nodded and spoke
Dad: I must say you have made a compelling case for vaccinations, Emily. I have to admit that I didn’t know half of what you said. [laughs]
Image of Emily laughing and talking
Emily: Many don’t. And there is a lot of misinformation out there about vaccines. That’s why I’m always ready to talk about them, at least until it’s time to make dessert…
Image of mom, laughing and getting up from the table
Mother: Speaking of which, who wants pumpkin pie?
Image of everyone standing at a table smiling and raising their hand
Image of dad receiving vaccination.
Want to make sure you and your loved ones are up to date on vaccines? Your healthcare provider, pharmacist or local health department can help.
You can also visit the CDC website to learn more about vaccines and vaccination schedules.
For more information, visit HealthyWomen.org
This resource was created with the support of Merck.