Annual Estimates of Influenza Vaccine Effectiveness for Preventing Laboratory Confirmed Influenza in the United States | Apply Online

FAQs: Annual Estimates of Influenza Vaccine Effectiveness (CDC Cooperative Agreement)

1) What is the main purpose of this CDC funding opportunity?

The opportunity supports projects that produce timely, credible, and repeatable annual estimates of seasonal influenza vaccine effectiveness (VE) in the United States, primarily for preventing laboratory-confirmed influenza. The goal is to generate actionable evidence early in each season and then update estimates over time as the season progresses.

2) Why does CDC emphasize annual vaccine effectiveness estimates?

Influenza viruses change continually, vaccines are reformulated annually, and influenza causes substantial illness, deaths, and healthcare strain across age groups. Because the vaccine and circulating viruses can change from season to season, VE needs to be measured repeatedly and quickly once epidemics begin (and also during a pandemic scenario, if one occurs).

3) What is meant by "vaccine effectiveness (VE)" in this program?

VE refers to how well seasonal influenza vaccines work in real-world conditions. The announcement highlights that VE is not a single one-size-fits-all number and can vary by season, population, vaccine formulation, and circulating viruses.

4) What outcomes are projects expected to evaluate?

At minimum, projects should evaluate laboratory-confirmed influenza infection. The opportunity also notes additional outcomes may be considered, such as symptomatic illness among those infected, progression to severe disease and complications, and potentially reductions in transmission to others.

5) Why is laboratory confirmation of influenza emphasized?

Laboratory confirmation is emphasized to define outcomes accurately and support credible VE estimates. It reduces reliance on non-specific clinical diagnoses and helps address the challenge that many respiratory illnesses are not influenza.

6) Does the CDC expect projects to use more than one data source or approach?

Yes. The announcement stresses that accurate VE estimation requires a multi-component approach rather than relying on a single data stream. This includes documenting vaccination status carefully, using laboratory-confirmed outcomes, measuring timing of vaccination and illness, and accounting for other factors that influence vaccine uptake and immune response.

7) What is the role of serology in this opportunity?

Applicants are expected to include serological assessment of vaccine response and influenza antibody outcomes in addition to observational effectiveness estimates. Serology is intended to help interpret why VE may vary by season, population, vaccine formulation, or circulating virus, and to provide insight into immune response patterns that explain field effectiveness results.

8) Is this opportunity focused on observational studies?

The announcement indicates that most real-world VE work relies on observational designs and explicitly requires planning for methodological challenges common to observational studies, including bias and confounding.

9) What methodological challenges does the announcement highlight that can bias VE estimates?

The opportunity calls out several practical issues that can affect VE estimates, including sensitivity and specificity of outcome measures, specimen collection methods, timing of vaccination relative to exposure, recruitment settings for cases and controls (clinical or community), and the underlying ratio of true influenza illness to non-influenza respiratory illness in the study population.

10) What factors can modify vaccine response or effectiveness according to the announcement?

The CDC notes that vaccine response and effectiveness can be modified by individual characteristics (such as age or underlying health conditions), environmental context, and viral or infectious disease factors. Applicants are expected to consider these influences in study design and analysis.

11) What does CDC expect regarding confounding and effect modification?

Proposed analyses must include clear plans to identify, measure, and control for confounding factors. The opportunity also expects applicants to evaluate potential effect modifiers when appropriate, reflecting that VE may differ across populations or contexts.

12) What does "timely" mean in the context of this program?

The program is oriented toward producing VE estimates as early as possible once seasonal epidemics begin, with continued monitoring over time. The intended product is early-season evidence followed by updated estimates during the season.

13) How would the results be used?

The intended use is to support real-world vaccination guidance and broader influenza control policy. The findings are meant to help public health leaders assess how well the current season's vaccine is performing and make more informed decisions about vaccination strategies and other control measures.

14) What type of award is this?

This was a discretionary CDC cooperative agreement, which implies CDC would have substantial involvement beyond simply awarding funds.

15) How many awards were expected?

The announcement indicated an expected five awards.

16) What is the CFDA number associated with this opportunity?

The program was listed under CFDA 93.185 (Immunization Research, Demonstration, Public Information and Education; Training and Clinical Skills Improvement Projects).

17) What was the maximum funding amount (award ceiling)?

The award ceiling was $785,000.

18) Was there a minimum award amount stated?

No minimum award amount was stated.

19) Was cost sharing or matching required?

No. The announcement stated there was no cost-sharing or matching requirement.

20) Who was eligible to apply?

Eligibility was described as unrestricted, meaning it was open to a broad range of applicant entity types, unless additional eligibility language in the full announcement imposed clarifications.

21) When was the opportunity posted and what were the key dates?

The opportunity was posted on January 10, 2011. The application deadline was March 1, 2011, and the archive date was March 31, 2011.

22) How were applications required to be submitted?

Applications had to be submitted electronically through Grants.gov and validated in eRA Commons by 5:00 PM Eastern Time on the due date.

23) What submission risk does the announcement specifically warn about?

The CDC noted that its procedures did not provide an error-correction window after the deadline for fixing submission problems flagged by Grants.gov or eRA systems. This means any issues needed to be resolved before the deadline.

24) Is the opportunity focused only on seasonal influenza, or also pandemics?

It is focused on seasonal influenza, with an explicit note that the system should be able to estimate VE in a pandemic scenario if one occurs.

25) What is the overall expected deliverable from funded projects?

The opportunity is essentially a call to build and run rigorous annual systems for estimating influenza VE in the United States using laboratory-confirmed outcomes, strengthened by serologic assessment, and supported by careful attention to timing, measurement quality, and statistical control of confounding, with outputs available early in each season and updated over time.