There are several types of research studies such as observational studies and clinical research trials, which you might have heard described as “clinical studies” or “randomized controlled trials”. The goal for these studies is to test a treatment or vaccine (like a COVID-19 vaccine) to see if it is safe and works to either prevent or treat a disease.
Randomized control trials (randomized clinical trials) are used for prevention studies such as vaccine research. They are called “randomized” because people are randomly assigned (as if by a coin toss) to either a placebo (saltwater) or to the treatment or product being tested. Researchers will usually randomly assign half the participants in a study to each assignment (placebo or product), but sometimes they will randomize more people to the treatment than the placebo. As the trial progresses, they collect information that allows them to determine if the treatment or vaccine works or not.
There are several stages of vaccine clinical studies:
Phase 1 studies test the safety of a product to see if there are side effects, and if people can tolerate the vaccine. These studies are conducted with a small group of people (usually less than 100) and typically last 12 to 18 months.
Phase 2 studies continue to look at the safety of the vaccine. They also start looking at the best way to give the vaccine and for signs that the immune system is having the desired response. In other words, are there signs that the vaccine will work to prevent COVID-19? These studies are with more people than the Phase 1 studies (usually a few hundred to 1000) and the studies can last up to 2 years.
Phase 3 studies are where researchers can ask the questions, “Does this vaccine prevent new infections? Or if people do become infected, does the product help them control the infection so they don’t get as sick?” These studies involve many thousands of people a can last for 1 to 4 years. These studies can lead to a vaccine being approved for use in the general population.
What are vaccines?
A vaccine is a substance that teaches your body to recognize a foreign invader, such as a virus, sound an alarm to activate your immune system, and instruct your fighter cells and proteins to go to work to fight the virus. The goal of a vaccine is to eliminate or control the virus in your body, which could prevent infection, or control an infection from developing into disease. The vaccine causes the immune system to respond by looking as much like the invading virus as possible without causing disease itself.
Vaccines have been used for decades around the world. While smallpox is the only infectious disease to date that has been eliminated globally by vaccination, vaccines have reduced the burden of many other infectious diseases such as influenza, polio, measles, mumps, and pertussis. Most recently, vaccines for the prevention of human papillomavirus (HPV), pneumonia, and shingles have been developed.
What research studies are you doing?
We are part of the COVID-19 Prevention Network (CoVPN), which will be doing studies in all phases in order to find safe and effective vaccines for the severe acute respiratory syndrome coronavirus type 2 (SARS-CoV-2), which is the virus that causes coronavirus disease 2019 (COVID-19).
These vaccines cannot cause SARS-CoV-2 infection or COVID-19. They do not contain any live or killed virus, so cannot cause an infection. Participants in these studies may be exposed to the virus in their everyday lives, but they will not be exposed to the virus as part of the study. These are vaccine studies that we hope will prevent people from becoming infected with SARS-CoV-2.