A multi-country investigation of influenza vaccine coverage in pregnant individuals, 2010-2016

Stephanie A Irving; Sarah W Ball; Stephanie M Booth; Annette K Regan; Allison L Naleway; Sarah A Buchan; Mark A Katz; Paul V Effler; Lawrence W Svenson; Jeffrey C Kwong; Becca S Feldman; Nicola P Klein; Hannah Chung; Kimberley Simmonds; PREVENT study team

doi:10.1016/j.vaccine.2021.11.018

A multi-country investigation of influenza vaccine coverage in pregnant individuals, 2010-2016

Vaccine. 2021 Dec 20;39(52):7598-7605. doi: 10.1016/j.vaccine.2021.11.018. Epub 2021 Nov 19.

Authors

Affiliations

¹ Kaiser Permanente Center for Health Research, Portland OR, USA. Electronic address: Stephanie.A.Irving@kpchr.org.
² Abt Associates, Cambridge MA, USA; Westat, Rockville, MD, USA.
³ Cumming School of Medicine, University of Calgary, Calgary, Canada.
⁴ School of Public Health, Curtin University, Perth, Australia; Wesfarmers Centre of Vaccines and Infectious Diseases, Telethon Kids Institute, Perth, Australia; School of Nursing and Health Professions, University of San Francisco, San Francisco, CA, USA.
⁵ Kaiser Permanente Center for Health Research, Portland OR, USA.
⁶ ICES, Toronto, Canada; Dalla Lana School of Public Health, University of Toronto, Toronto, Canada; Public Health Ontario, Toronto, Canada.
⁷ Clalit Research Institute, Tel Aviv, Israel; Medical School for International Health and School of Public Health, Ben Gurion University of the Negev, Beersheva, Israel; University of Michigan School of Public Health, Ann Arbor MI, USA.
⁸ Communicable Disease Control Directorate, Department of Health Western Australia, Perth, WA, Australia.
⁹ Cumming School of Medicine, University of Calgary, Calgary, Canada; Alberta Ministry of Health, Edmonton, Canada; Division of Preventive Medicine, University of Alberta, Edmonton, Canada; School of Public Health, University of Alberta, Edmonton, Canada.
¹⁰ ICES, Toronto, Canada; Medical School for International Health and School of Public Health, Ben Gurion University of the Negev, Beersheva, Israel; Public Health Ontario, Toronto, Canada; Department of Family and Community Medicine, University of Toronto, Toronto, ON, Canada; University Health Network, Toronto, ON, Canada.
¹¹ Clalit Research Institute, Tel Aviv, Israel.
¹² Kaiser Permanente Vaccine Study Center, Oakland, CA, USA.
¹³ ICES, Toronto, Canada.
¹⁴ Cumming School of Medicine, University of Calgary, Calgary, Canada; Alberta Ministry of Health, Edmonton, Canada.

PMID: 34802789
DOI: 10.1016/j.vaccine.2021.11.018

Abstract

Background: Many countries recommend influenza vaccination during pregnancy. Despite this recommendation, influenza vaccine among pregnant individuals remains under-utilized and uptake varies by country. Factors associated with influenza vaccine uptake during pregnancy may also vary across countries.

Methods: As members of the Pregnancy Influenza Vaccine Effectiveness Network (PREVENT), five sites from four countries (Australia, Canada, Israel, and the United States) retrospectively identified cohorts of individuals aged 18-50 years who were pregnant during pre-defined influenza seasons. Influenza vaccine coverage estimates were calculated for the 2010-11 through 2015-16 northern hemisphere and the 2012 through 2015 southern hemisphere influenza seasons, by site. Sites used electronic health records, administrative data, and immunization registries to collect information on pregnancy, health history, demographics, and vaccination status. Each season, vaccination coverage was calculated as the percentage of individuals who received influenza vaccine among the individuals in the cohort that season. Characteristics were compared between those vaccinated and unvaccinated, by site.

Results: More than two million pregnancies were identified over the study period. Influenza vaccination coverage ranged from 5% to 58% across sites and seasons. Coverage increased consistently over the study period at three of the five sites (Western Australia, Alberta, and Israel), and was highest in all seasons at the United States study site (39-58%). Associations with vaccination varied by country and across seasons; where available, parity >0, presence of a high-risk medical condition, and urban residence were consistently associated with increased likelihood of vaccination.

Conclusions: Though increasing, uptake of influenza vaccine among pregnant individuals remains lower than recommended. Coverage varied substantially by country, suggesting an ongoing need for targeted strategies to improve influenza vaccine uptake in this population.

Keywords: Influenza; Multi-country; Pregnancy; Vaccination; Vaccination Coverage.

Publication types

Research Support, Non-U.S. Gov't
Research Support, U.S. Gov't, P.H.S.

MeSH terms

Alberta
Female
Humans
Influenza Vaccines*
Influenza, Human* / prevention & control
Pregnancy
Retrospective Studies
Seasons
United States
Vaccination
Vaccine Efficacy

Substances

Influenza Vaccines

Grants and funding

CC/CDC HHS/United States