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Killer Disease on Campus

Making Vaccines
Toxoid vaccine: tetanus

 


Tetanus step 1

Step 1
Use the growth medium to grow new copies of the Clostridium tetani bacteria.



 

With a toxoid vaccine, the goal is to condition the immune system to combat not an invading virus or bacteria but rather a toxin produced by that invading virus or bacteria. The tetanus shot is such a vaccine. Tetanus is a disease caused by toxins created by the bacteria Clostridium tetani. The vaccine conditions the body's immune system to eliminate these toxins.

To produce the vaccine, you first need to grow many copies of the Clostridium tetani bacteria.



Tetanus step 2

Step 2
Isolate the toxins with the purifier.



 

While in the growth medium, the bacterial cells produce the toxin, which are toxic molecules that are often released by the cells.

To produce the vaccine, you'll need to separate these molecules from the bacteria and the growth medium.



Tetanus step 3

Step 3
Add aluminum salts to the purified toxins.



 

In this state, the toxin would be harmful to the human body. To make the vaccine, it needs to be neutralized.

Sometimes formaldehyde is used to neutralize toxins. For your vaccine, you'll use aluminum salts to decrease its harmful effects.



Tetanus step 4

Step 4
Fill the syringe with the treated toxins.



 

The toxin would work as a vaccine now, but it wouldn't stimulate a strong immune response. To increase the response, an "adjuvant" is added to the vaccine.

For the tetanus vaccine, another vaccine acts as the adjuvant. This other vaccine inoculates against pertussis. The vaccine for diphtheria -- also a toxoid vaccine -- is also often added to the tetanus/pertussis combo, making for the DPT vaccine.



Tetanus done

Done
The tetanus vaccine is complete.

Select another pathogen.



 

Congratulations. You have produced a toxoid vaccine for tetanus.

As with other inactivated vaccines, there are disadvantages with toxoid vaccines. Even with the adjuvant, these vaccines do not produce a full immune response. Booster shots are needed to maintain the immunity.




Smallpox icon

Similar-pathogen vaccine:
smallpox virus

  Measles icon

Attenuated vaccine:
measles virus

  Polio icon

Killed vaccine:
polio virus

Tetanus icon

Toxoid vaccine:
tetanus

  Hepatitis icon

Subunit vaccine:
hepatitis B

  HIV icon

Naked-DNA vaccine:
HIV



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NOVA Home Page Find out what's coming up on air Listing of previous NOVA Web sites NOVA's history Subscribe to the NOVA bulletin Lesson plans and more for teachers Tell us what you think Program transcripts Buy NOVA videos or DVDs Answers to frequently asked questions An index of the NOVA site