Understanding immune responses to influenza vaccination in health care workers

Immune Responses to Influenza Vaccinations and Viruses Among Health Care Personnel

Observational Finnish Institute for Health and Welfare · NCT03323112

This study looks at how the flu vaccine affects the immune system of health care workers over ten years to see how well it protects them from the virus.

Quick facts

Study typeObservational
Enrollment150 (estimated)
Ages18 Years to 64 Years
SexAll
SponsorFinnish Institute for Health and Welfare Government
Locations1 site (Helsinki)
Trial IDNCT03323112 on ClinicalTrials.gov

What this trial studies

This observational study aims to enhance knowledge about the immune responses elicited by influenza vaccination among health care personnel over a 10-year period. Participants will receive the seasonal influenza vaccine as per routine occupational health care practices, with blood samples collected before vaccination, five weeks after, and six months post-vaccination. The study will analyze both humoral and cellular immunity, the effects of repeated vaccinations, and factors influencing immunological responses. The analysis will primarily be descriptive, focusing on the duration of protection and immunity against circulating viruses.

Who should consider this trial

Good fit: Ideal candidates include health care or laboratory personnel in good health who choose to receive the seasonal influenza vaccination.

Not a fit: Patients with immunosuppressive conditions, pregnancy, or contraindications for influenza vaccination may not benefit from this study.

Why it matters

Potential benefit: If successful, this study could lead to improved vaccination strategies and enhanced protection against influenza for health care workers.

How similar studies have performed: Other studies have explored immune responses to vaccinations, but this specific long-term observational approach focusing on health care workers is relatively novel.

Eligibility criteria

Show full inclusion / exclusion criteria
Inclusion Criteria:

* Members of health care or laboratory personnel in HUS having decided to take the seasonal influenza vaccination by the routine occupational health care service
* General good health as established by or volunteer's own statement
* Written informed consent
* Presumably able and willing to participate in the study during the starting influenza season

Exclusion Criteria:

* Any confirmed or suspected immunosuppressive or immunodeficient condition, including human immunodeficiency virus (HIV) infection.
* Administration (longer than 14 days) of immunosuppressants or other immune- modifying drugs within 6 months before the vaccination; oral corticosteroids in dosages of 20 mg/day or more prednisolone or equivalent are excluded; inhaled or topical steroids are allowed.
* Pregnancy or lactation
* Acute disease at the time of enrolment (defined as the presence of a moderate or severe illness with or without fever)
* Contraindication for influenza vaccination
* Any other criteria which, in the investigator's or dedicated study staff member's opinion, would compromise the ability of a subject to participate in the study, a subject's well-being, or the outcome of the study

Where this trial is running

Helsinki

Study contacts

How to participate

  1. Review the eligibility criteria above with your treating physician.
  2. Visit the official trial page on ClinicalTrials.gov for the most current contact information and recruitment status.
  3. Contact the listed study coordinator or principal investigator to request pre-screening. Pre-screening is free and never obligates you to enroll.
Conditions Influenzainfluenzavaccinationhealth care workersimmune responseshumoral immunitycellular immunity
Last reviewed 2026-06-13 by the Find a Trial editorial team. Information on this page is for educational purposes and is not medical advice. Always consult qualified healthcare professionals about clinical trial participation.