Long-term Observation of Hemagglutinin and Neuraminidase Inhibition Antibody Titers After Influenza Challenge



Status:Recruiting
Conditions:Influenza
Therapuetic Areas:Immunology / Infectious Diseases
Healthy:No
Age Range:18 - 100
Updated:3/14/2019
Start Date:July 17, 2015
End Date:May 27, 2027
Contact:Holly A Baus, R.N.
Email:holly.baus@nih.gov
Phone:(301) 761-6800

Use our guide to learn which trials are right for you!

Long-Term Observation of Hemagglutinin and Neuraminidase Inhibition Antibody Titers After Influenza Challenge

Background:

- Influenza is a common viral infection. But it can be deadly for some people. Researchers
want to learn more about how the body fights this virus. They want to study this in people
who have recently been infected with influenza. They hope this can help them create more
effective influenza vaccines.

Objective:

- To learn about long-term changes in the body s immune system after influenza infection.

Eligibility:

- People who have completed a previous LID Clinical Studies Unit influenza challenge study
and are willing to have samples stored for future research.

Design:

- Eligible participants will be asked to visit the clinic every 3 months for 2 years.

- During each visit, participants will have blood drawn from an arm vein using a needle
and a syringe.

- Participants will have a medical history and physical exam and vital signs performed.
This will include blood pressure, heart rate, breathing rate, temperature, weight, and
finger-measured blood oxygen. They will answer questions about any medicines taken and
possible recent illnesses.

- If participants have symptoms of influenza, they may have a sample taken from the nose.
A small amount of salt water will be sprayed into the nostril with a squeezable
container. The salt water will then run out of the nose and into the container. Or the
inside of the nose will be wiped with a swab that is

similar to a Q-tip.

- Participants will complete a health questionnaire once a month on a secure website.
Participants may also give their responses over the telephone.

Circulating anti-influenza antibodies are an important factor in predicting clinical illness
and severity in those infected with influenza. Specific antibodies against influenza include
proteins targeting hemagglutinin (HA) and neuraminidase (NA). Lifelong immunity does not
occur with influenza, either from natural infection or from vaccination. Due to the antigenic
variation of Influenza A, individuals may become infected multiple times with the same
subtype of influenza and even with the same strain. In the setting of natural infection and
vaccination, antibody titer levels can persist initially, but then wane over time.

In our previous challenge studies, measurements of antibody responses have been focused
solely on the acute infection period up to 2 months after initial infection. Long-term
changes in immunity have not been investigated. The challenge setting gives us the unique
ability to follow individuals from a specific, known and well-characterized exposure/illness
to measure long-term changes in antibody titers from a pre-exposure baseline. This study
could offer unique insight into how anti-influenza antibody titers change over time naturally
and in response to other infections and life events. This type of controlled study has never
been done and we believe monitoring titers long-term will help us better understand
protective correlates of influenza.

In this natural history study, we will follow individuals who have undergone influenza
challenge or have been naturally infected with influenza to evaluate changes in
anti-influenza antibody titers over a 2-year period. Subjects will be followed for symptoms
of influenza-like illness (ILI) and other changes in clinical status through quarterly
clinical evaluations with blood draws. Monthly questionnaires will be used to follow subjects
in between visits.

- INCLUSION CRITERIA:

1. Completion of participation in an LID Clinical Studies Unit influenza challenge
study or current or prior participation in an LID natural history study.

2. Willing to have samples stored for future research.

CO-ENROLLMENT GUIDELINES:

Participants may be co-enrolled in other research studies. This will be addressed on a
case-by-case basis with the approval of the principal investigator (PI) or associate
investigator.

If a participant enrolls in another influenza challenge study, the participant will be
removed from this study. The participant can re-enroll in this study after completion of
the influenza challenge study and will be followed for two years following completion of
the most recent influenza challenge study.

EXCLUSION CRITERIA:

Any condition or event that, in the PI s opinion, may substantially increase the risk
associated with study participation or compromise the study s scientific objectives.
Conditions that exclude a subject are considered to be unlikely, but an example would
include a newly diagnosed medical condition that may alter a participant s immune system
and make it unsafe to obtain scheduled blood samples for research purposes.
We found this trial at
1
site
9000 Rockville Pike
Bethesda, Maryland 20892
Phone: 800-411-1222
?
mi
from
Bethesda, MD
Click here to add this to my saved trials