ACIP to use GRADE approach to systematically assess vaccine evidence

GRADE framework will allow committee to determine degree of confidence in estimating the effect of vaccination on health outcomes.

A new framework for developing evidence-based recommendations for the use of vaccines has been adopted by CDC’s Advisory Committee on Immunization Practices (ACIP). As reported in the May 10 Morbidity and Mortality Weekly Report, ACIP will use the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach.

The GRADE framework will allow the committee to systematically assess the type or quality of evidence regarding a vaccine’s expected health effects, the balance of health benefits and risks, and the values and preferences of affected individuals, as well as allow for health economic analyses. ACIP expects the GRADE approach to improve transparency, consistency, and communication.

In using GRADE, evidence will be grouped into four categories, the order of which will indicate the degree of confidence that ACIP will have in estimating the effect of vaccination on health outcomes:

  1. Randomized controlled trials (RCTs) or unequivocal evidence from observational studies
  2. RCTs with important limitations or "exceptionally strong" evidence from observational studies
  3. Observational studies or RCTs with noteworthy limitations
  4. Clinical experience and observations, observational studies with considerable limitations, or RCTs with numerous major limitations

GRADE is used by more than 60 organizations, including the American Academy of Family Physicians, American College of Physicians, Infectious Diseases Society of America, and World Health Organization.

Frequently asked questions regarding GRADE are available at the GRADE working group website.