Your Questions about COVID-19 Vaccine Development Answered
When developing a vaccine, researchers need to ensure it’s both safe and efficacious—in other words, that it works.
“Although there are several different types of COVID-19 vaccines in development around the world, the process for testing the safety and efficacy of these vaccines is very similar,” said Linda Jones, DNS, RN, vice president of ancillary operations for Memorial Health System and a member of the MHS Vaccine Steering Committee. “The requirements for the COVID-19 vaccine are the same as for all other vaccines.”
All vaccine development starts in a lab. When researchers are confident in the vaccine they have created, they first test it on animals. The purpose of these tests is to ensure that the vaccine can spur an immune response. However, success in animals does not necessarily mean that the same response will occur in humans.
Therefore, the next step is three stages of clinical trials involving humans. The first and second of these stages involve a relatively small number of people and are intended to make sure the vaccine meets goals for safety and efficacy. By the third stage, however, tens of thousands of people are involved. In each of these stages, some volunteers will get the candidate vaccine and others will get a placebo.
The third stage of human testing explores whether the vaccine can prevent illness in “real-world” conditions. Researchers compare the number of people who got COVID-19 after receiving the vaccine with the number of people who got COVID-19 after receiving a placebo.
“The results for the Pfizer and Moderna vaccines have both been very positive, with effectiveness rates over 90 percent,” Jones noted.
The vaccine development process usually takes several years. But these COVID-19 vaccines received Food and Drug Administration authorization through a process called Emergency Use Authorization. This is the same authorization that has allowed researchers to quickly develop therapies like convalescent plasma that we use to treat COVID-19.
How is it possible for COVID-19 vaccines to move through the appropriate safety measures at such a rapid pace? Vaccine companies gained efficiency because they were able to bypass some normally time-consuming administrative steps, such as obtaining funding, evaluating whether or not there will be demand for the vaccine and enrolling enough participants for the clinical trials. In the face of a pandemic, the demand is great and participants stepped up quickly to enroll in clinical trials.
Additionally, vaccine trials require individuals to be infected with the disease, which can take years for other diseases. “With high rates of COVID-19 transmission across the U.S., we were quickly able to reach the number of infections required to ensure thorough safety testing of the vaccine and see its impact,” Jones said.