Vaccines are a constant topic of conversations lately. With COVID-19, having a vaccination could prevent millions of people from becoming seriously ill. As much as it is dominated the news and changing our lives, this coronavirus is still just one in a long history of illnesses that have had the potential to take lives on a large scale.
Smallpox was the first deadly disease to threaten humanity globally. It was first identified in 1545 and was responsible for killing 8,000 children in India. The disease progressed through Europe then traveled to the New World where it almost wiped out the Native Americans and many pilgrims. Today, we don’t think much about smallpox. Although it was fatal almost 30% of the time, a global vaccination program eradicated the disease. The last known natural case was in Somalia in 1977.
Vaccines are no small miracle. From the time a disease is first identified to the time that an effective vaccination is developed, many years can pass. With the COVID-19, the process is the same but the people working on the vaccine are trying to accelerate the process substantially.
Making a vaccine
There are basically four ways to make a vaccination:
- Using a weakened form of the virus
- Using an inactive form of the virus
- Using a part of the virus
- Using a part of the bacteria causing the virus
When a weakened form of the virus is used, they don’t reproduce well in the body. But the body can still recognize that there is a virus present, so antibodies are formed to fight it. The vaccines for measles, mumps, German measles (rubella), and chickenpox work this way. Because the virus is weakened, one or two doses are enough to give lifetime immunity. However, vaccines like these that use actual viruses are not given to people who have a weakened immune system.
This is a virus that has been inactivated chemically. Polio, hepatitis A, influenza, and rabies vaccines are made this way. The inactive virus can be detected by the body and generate cells to fight the active one. This type of vaccine can be given to people who have a weakened immune system. It won’t even cause a mild form of the disease.
Using part of the virus
In some vaccines, only a part of the virus is used, specifically the protein that lives on its surface. Vaccines that use a part of the virus to build immunity include hepatitis B, human papillomavirus, and shingles.
Using part of the bacteria
Viruses that start with bacteria include diphtheria, tetanus, and pertussis. The bacteria produces a toxic protein that causes people to get sick. To make the vaccination, the toxin is deactivated so it can no longer cause disease but is still recognized by your body. By using the inactive toxin as the vaccination, your immune system can make the antibodies to prevent infection.
Testing and trials
Once a vaccine is developed, it must go through testing and trials. Testing in the lab comes first. When the lab deems the vaccine safe, it goes through clinical trials with people who volunteer to take the vaccination. Eventually the vaccine is tried on thousands of people to determine if it is safe for humans. Testing a large sample of people also verifies that the immune system reacts correctly and that the dosage is correct.
The Food and Drug Administration (FDA) works closely with the company producing the vaccine through the process of evaluating safety and effectiveness. After all safety concerns are addressed and the vaccine is proven to work, the FDA licenses the vaccine. At that point, the vaccine can be given to the general public to prevent disease.
But the testing doesn’t end there, vaccines continue to be tested throughout the manufacturing process. Each batch is tested to make sure the vaccine is potent, pure and sterile. These testing results are reviewed by the FDA, and the factories making the vaccine are inspected multiple times to make sure it continues to meet the standards for quality and safety.
For more on developing a vaccine for COVID-19, view this video interview by the Journal of the American Medical Association.