How biopharmaceutical researchers are ensuring COVID-19 vaccines will be safe and effective­

Yet no matter the approach, biopharmaceutical researchers must comply with a number of regulations throughout the development process to help ensure vaccine safety.


How biopharmaceutical researchers are ensuring COVID-19 vaccines will be safe and effective­.

As the world continues to feel the impact of COVID-19, the biopharmaceutical industry is working around the clock to identify and develop safe and effective vaccines to prevent infection, while also researching and developing new therapies to treat those infected with the virus. Given the pressing need, along with the volume of information that remains unknown about the disease, a wide range of approaches are being tested to greatly improve the odds that one or more vaccine candidates will be successful.

Yet no matter the approach, biopharmaceutical researchers must comply with a number of regulations throughout the development process to help ensure vaccine safety.

Ensuring Safety Is Foundational Throughout the Vaccine Research and Development Process

Evaluation of vaccine safety begins in the earliest phases of research, with preclinical trials involving animal and human cells or tissue systems. In this phase, scientists examine whether vaccine candidates produce the outcome they expect, as well as look for any signs of negative reactions.

If a candidate is successful in preclinical studies, researchers then conduct early clinical studies with a small number of human participants — often no more than a few dozen — specifically to examine safety. Participants are given a wide range of vaccine doses, both higher and lower than the expected dose needed to be effective, and scientists carefully examine the immune system response. If everything goes as expected, the vaccine candidate can advance to longer and larger studies which are designed to study safety and efficacy in larger and more diverse groups of people.

Additional clinical trials examine the vaccine in hundreds to even a few thousand people to better understand how the immune system responds to a vaccine, whether it is effective and durable at producing immunity and the safety profile. Depending on the vaccine and disease under study, thousands or even tens of thousands of participants may participate to further increase understanding of vaccine safety. Specifically,COVID-19 vaccine candidates will have to meet the same standards for clinical trials as other vaccines, including testing in very large (30,000 participants) phase 3 trials.

Safety Evaluation Continues Even after a Vaccine Is Approved

Researchers closely monitor data, including any reports of adverse events, throughout the clinical trial to understand the safety profile of the vaccine and take steps as appropriate to improve the safety profile. And if a vaccine candidate is found to be safe and effective and receives approval from the U.S. Food and Drug Administration (FDA), biopharmaceutical companies continue to take steps to help ensure product safety, including through manufacturing controls that help ensure quality and through surveillance and assessment of adverse events.

The Centers for Disease Control and Prevention’s (CDC) Immunization Safety Office further “uses many strategies to assess vaccine safety, to identify health problems possibly related to vaccines, and to conduct studies that help determine whether a health problem is caused by a specific vaccine. CDC also works with other federal government agencies and other stakeholders to determine the appropriate public health response to vaccine safety concerns and to communicate the benefits and risks of vaccines.”

Public Health Experts Agree: Vaccines are safe and effective.

Vaccines represent some of the most impactful advances in public health, helping to prevent the spread of many infectious diseases and, in many parts of the world, eliminating some of the most devastating conditions. In the United States, 16 diseases are now preventable as a result of childhood vaccines, resulting in an estimated $1.4 trillion in societal costs saved.

Over the years, biopharmaceutical companies have advanced new technologies that further address safety including better methods of analyzing the interaction of vaccines and the immune system, as well as improved manufacturing capabilities. This means biopharmaceutical researchers have the specialized skills and experience to navigate development successfully, and they understand the pressing need for a safe and effective vaccine to help combat COVID-19.

To learn more about the efforts underway to develop COVID-19 vaccines, visit

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