Skip to main content

Oregon State Flag An official website of the State of Oregon » Homepage

Trivalent Inactivated Influenza Vaccine (TIV) Effectiveness

The U.S. Centers for Disease Control and Prevention (CDC) launched the Emerging Infections Program (EIP) to develop centers of excellence in infectious disease surveillance and applied public health research in selected state health departments. The Oregon EIP is participating in the study described below.


Trivalent Inactivated Influenza Vaccine (TIV) Effectiveness

Effectiveness Evaluation - Abstract

The TIV study is a multi-state study funded by CDC to determine the effectiveness of TIV among persons 50 and older in preventing laboratory confirmed hospitalizations.

The primary method of preventing complications from community-acquired influenza virus infections among adults is vaccination with trivalent inactivated influenza vaccine (TIV). Annual vaccination with the influenza vaccine has been recommended for adults aged 65-years and older for many years by the Center for Disease Control and Prevention's Advisory Committee on Immunization Practices (ACIP). This is because these adults are at higher-risk of influenza-associated hospitalization and death than younger persons.

In 2009, ACIP began recommending that all adults aged 50-years and older receive TIV annually due to some medical conditions that place adults at high-risk for influenza complications (e.g., pulmonary and cardiac conditions) are more prevalent among individuals aged 50-64 years than the general population.

Many previous studies of the effectiveness of TIV in adults have been conducted; however, there is only one vaccine effectiveness research study against RT-PCR-confirmed influenza hospitalizations among adults aged 50-64 years, and none among adults aged 65 years and older.

Evaluators will estimate the effectiveness of TIV against influenza-confirmed hospitalizations among adults aged 50 years and older for whom annual vaccination is recommended during several influenza seasons.

To see all Oregon Emerging Infections Program special studies go to EIP special studies.