Vaccines

Third participant enrolled in VRC 207 receives a dose of the investigational NIAID/GSK Ebola vaccine

A clinical trial participant receives a dose of an investigational Ebola vaccine at the NIH Clinical Center.

Credit: NIAID

Vaccines stimulate the immune system to produce immune responses that protect against infection. Vaccines provide a safe, cost-effective and efficient means of preventing illness, disability and death from infectious diseases.

Why Is Vaccine Research a Priority for NIAID?

Vaccines have saved millions of lives worldwide and dramatically reduced the prevalence of many life-threatening infectious diseases. Yet there remains a need for new and improved vaccines against existing infectious diseases, as well as a need for rapid development of experimental vaccines to address emerging infectious diseases. NIAID supports and conducts research to identify new vaccine candidates to prevent a variety of infectious diseases, including those for which no vaccines currently exist.  NIAID-supported research also aims to improve the safety and efficacy of existing vaccines.

How Is NIAID Addressing This Important Area of Study?

NIAID conducts and supports numerous stages of the vaccine development process, ranging from basic immunology research to clinical testing of candidate vaccines. Basic research aims to understand the complex interactions between pathogens and their human hosts and generate the knowledge essential for developing safe and effective vaccines. Preclinical research helps advance promising vaccine candidates into human testing. Clinical trials evaluate the safety, tolerability and efficacy of investigational vaccines in people.

For general health information about vaccines, visit Vaccines.gov and the Centers for Disease Control and Prevention’s Vaccines & Immunizations site.

Types of Vaccines

Scientific research has led to the development of numerous types of vaccines that safely elicit immune responses that protect against infection, and researchers continue to investigate novel vaccine strategies for prevention of existing and emerging infectious diseases.

Vaccine Adjuvants

A vaccine adjuvant is a substance that is formulated as part of a vaccine to enhance its ability to induce protection against infection. Adjuvants help activate the immune system, allowing the antigens—pathogen components that elicit an immune response—in vaccines to stimulate a response that leads to long-term protection.

Making Safe Vaccines

Each person’s immune system works differently, so occasionally a person will not respond to a vaccine. Very rarely, a person may have a serious adverse reaction to a vaccine, such as an allergic reaction that causes hives or difficulty breathing. But serious reactions are reported so infrequently—about once every 100,000 vaccinations—that they can be difficult to detect and confirm. More commonly, people will experience temporary side effects, such as fever, soreness, or redness at the injection site. These side effects are, of course, preferable to getting the illness. 

Disease-Specific Vaccines

NIAID supports and conducts research to identify new vaccine candidates to prevent a variety of infectious diseases, including those for which no vaccines currently exist. NIAID-supported research also aims to improve the safety and efficacy of existing vaccines.

Content last reviewed on July 1, 2019