Influenza Vaccine Effectiveness of a Quadrivalent Vaccine in Pregnant Women and Young Infants, 2019-2020

National and Kapodistrian University of Athens

Status: Completed

Conditions: Influenza in Human

Study type: Observational

Funder types: Other

Identifiers

NCT04723771

16708

Details and patient eligibility

About

Influenza is associated with an increased risk for serious illness, hospitalization and death in pregnant women and young infants. The investigators estimated the effectiveness of a quadrivalent inactivated influenza vaccine (QIV) in pregnant women and their infants in 2019-2020 influenza season. Women were activelly followed during the influenza season on a weekly basis through telephone call in order to collect data about the onset of fever and/or respiratory symptoms by them or their young infants. Polymerase chain reaction testing in pharyngeal samples was offered to pregnant women and infants with influenza-like illness (ILI). A total of 636 pregnant women and 474 infants were studied. A Bayesian beta-binomial model was used.

Full description

Study period: Influenza 2019-2020 season

The investigators followed actively the pregnant women and their infants in order to collect prospectively data on a weekly basis through phone calls during the entire influenza season.

Definitions:

• ILI was defined as the sudden onset of symptoms and fever, malaise, myalgia or headache, and cough, sore throat or shortness of breath.
• ARI was defined as the presence of at least one respiratory symptom, regardless of fever.
• Febrile episode was defined as the presence of fever only.
• Fever was defined as a temperature of 38.0 C in at least two measurements within 24h.
• The diagnoses of pneumonia and AOM were accepted as reported by the physicians who provided care to the women or their infants.

The 2019-2020 QIV Vaxigrip-Tetra was used to vaccinate pregnant women.

Enrollment: 949 patients

Sex: Female

Ages: 18 to 45 years old

Volunteers: Accepts Healthy Volunteers

Inclusion criteria

Pregnant women >18 years old and <45 years old, cared at Alexandra General Hospital (Athens, Greece) between October 16 and January 27, 2020

Exclusion criteria

• <18 years old or >45 years old
• not in stable health
• already vaccinated against influenza
• history of Guillain-Barré syndrome
• history of hypersensitivity to influenza vaccines
• immunosuppression
• history of investigational drug <30 days
• history of immunoglobulins or blood products <3 months
• fever at day of interview (enrollment day)

Trial design