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Immune Responses in Health Care Personnel

Immune Responses to Influenza Vaccinations and Viruses Among Health Care Personnel

Status
Recruiting
Phases
Unknown
Study type
Observational
Source
ClinicalTrials.gov
Registry ID
NCT03323112
Enrollment
150
Registered
2017-10-26
Start date
2017-10-18
Completion date
2027-10-14
Last updated
2025-08-20

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Influenza

Keywords

influenza, vaccination, health care workers, immune responses, humoral immunity, cellular immunity

Brief summary

This is an investigator-initiated 10 year long open cohort observational study, aiming to increase the understanding of the humoral and cellular immunological mechanisms of vaccination against influenza, including effects of repeated vaccination, the duration of protection, immunity against circulating viruses, as well as factors affecting the immunological responses and immunity against other vaccine preventable infectious diseases among health care personnel.

Detailed description

Influenza vaccination is given according to the normal routine of Hospital District of Helsinki and Uusimaa (HUS) occupational health care. Blood samples will be collected before vaccination, 5 weeks after vaccination and 6 months after vaccination. Both the same participants and also new participants will be recruited each year. The analysis will be mainly descriptive.

Interventions

BIOLOGICALinfluenza vaccine

Vaccine for prevention of influenza. Vaccines change by influenza season.

Sponsors

Hospital District of Helsinki and Uusimaa
CollaboratorOTHER
Finnish Institute for Health and Welfare
Lead SponsorOTHER_GOV

Study design

Observational model
COHORT
Time perspective
PROSPECTIVE

Eligibility

Sex/Gender
ALL
Age
18 Years to 64 Years
Healthy volunteers
Yes

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

Design outcomes

Primary

MeasureTime frameDescription
Humoral immunity against each present season's vaccine and circulating influenza strains10 yearsThe presence and titer of antibodies against circulating influenza virus strains and vaccine strains of the current season from pre- and post-vaccination serum samples

Secondary

MeasureTime frameDescription
Humoral immunity against previous seasons' vaccine and circulating influenza strains10 yearsTo assess the presence and titer of antibodies to circulating influenza strains and vaccine virus strains of previous seasons from pre- and post-vaccination serum samples
Cellular immunity against current and previous seasons' vaccine and circulating influenza strains10 yearsThe cellular immune responses to circulating influenza viruses and vaccine strains of the current and previous seasons from pre- and post-vaccination peripheral blood mononuclear cells (PBMCs) and cell culture supernatants
Effect of repeated vaccination against influenza10 yearsThe effect of the number of previous influenza vaccinations on the quality and quantity of Humoral and cellular immunity to circulating influenza strains and vaccine strains of the current and previous seasons

Other

MeasureTime frameDescription
Immunity against other microbes causing vaccine preventable diseases among health care workers10 yearsAssessment of humoral and cellular immunity to microbes other than influenza virus causing vaccine preventable diseases
Developing methods to measure immunity against vaccine preventable diseases10 yearsdeveloping laboratory methodologies to assess immunity to influenza and other microbes causing vaccine preventable diseases
Factors affecting humoral and/or cellular immune responses to influenza viruses or vaccination10 yearsExploration of biological or chemical factors that are/will be known or suspected to affect the humoral and/or cellular immune responses to influenza viruses or vaccination

Countries

Finland

Contacts

Primary ContactHanna Nohynek, MD, PhD
hanna.nohynek@thl.fi+358 29 524 8246
Backup ContactMerit Melin, PhD
merit.melin@thl.fi+358 29 524 8903

Outcome results

None listed

Source: ClinicalTrials.gov · Data processed: Feb 4, 2026