Evaluation of the Effectiveness of Vaccination With 2009 H1N1 Vaccines During Influenza Season 2010-11

Completed

• Conditions: Influenza Caused by the 2009 H1N1 Influenza Virus
• Interventions: Other: Follow-up

• Registration Number: NCT01206114
• Lead Sponsor: Finnish Institute for Health and Welfare

Brief Summary

A cohort of 3000 adults is followed to evaluate the effectiveness of the monovalent 2009 H1N1 vaccines used 2009-2010 and seasonal influenza vaccines used 2010-2011 in preventing the first laboratory-confirmed 2009 H1N1 influenza during the influenza season 2010-11.

Detailed Description

In the beginning of the study, changes in the background information collected in the original study (conducted 2009-2010) are asked with a questionnaire. Information on influenza vaccinations is collected with vaccination cards and monthly short message service (SMS), and verified in registers, if needed. If an epidemic caused by the 2009 H1N1 virus starts in Finland, the participants are asked to actively report symptoms of influenza like illnesses (ILI). The symptoms are also monitored by weekly SMS. In case of ILI, nasal and oral swabs are collected to verify the 2009 H1N1 influenza cases. Paired serum samples are collected at the acute on convalescence phase of the disease. The occurrence of laboratory-confirmed 2009 H1N1 influenza cases is compared between vaccinated and not (yet) vaccinated persons.

Study Timeline

• Study Start: 2010-09
• Study First Submitted: 2010-09-20
• Study First Submitted QC: 2010-09-20
• Study First Posted: 2010-09-21
• Primary Completion: 2011-04
• Status Verified: 2014-09
• Study Completion: 2014-09
• Last Update Submitted: 2014-09-24
• Last Update Posted: 2014-09-25

Recruitment & Eligibility

• Status: COMPLETED
• Sex: All
• Target Recruitment: 2351

Inclusion Criteria

Not provided

Exclusion Criteria

Not provided

Study & Design

• Study Type: OBSERVATIONAL
• Study Design: Not specified

Arm && Interventions

Group	Intervention	Description
Not (yet) vaccinated persons	Follow-up	The participants do not want to take any 2009 H1N1 vaccine or have not received any yet
Vaccinated persons	Follow-up	The participants have taken one or more doses of 2009 H1N1 vaccine, either as a monovalent vaccine or as a part of a trivalent seasonal 2010-2011 influenza vaccine

Primary Outcome Measures

Name	Time	Method
To determine the effectiveness of 2009 H1N1 influenza vaccination in preventing the first episode of laboratory-confirmed influenza caused by the 2009 H1N1 virus during the season 2010-11 among vaccinated adults as compared to unvaccinated adults	September 2010 to April 2011

Secondary Outcome Measures

Name	Time	Method
To evaluate the incidence, severity and possible complications of laboratory-confirmed infection with the 2009 H1N1 influenza virus	September 2010 to April 2011
To explore the effectiveness of the 2009 H1N1 vaccines in subgroups stratified by age	September 2010 to April 2011
To explore the ability of different vaccination regimens to prevent 2009 H1N1 influenza	September 2010 to April 2011

Trial Locations

Locations (1)

National Institute for Health and Welfare; 🇫🇮 Tampere, Finland