Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2019;15(3):687-699.
doi: 10.1080/21645515.2018.1540807. Epub 2018 Nov 15.

The safety of inactivated influenza vaccines in pregnancy for birth outcomes: a systematic review

Michelle L Giles  1 , Sushena Krishnaswamy  2 , Kristine Macartney  3 , Allen Cheng  4
Affiliations

The safety of inactivated influenza vaccines in pregnancy for birth outcomes: a systematic review

Michelle L Giles et al. Hum Vaccin Immunother. 2019.

Abstract

Pregnant women are at increased risk of morbidity and mortality from influenza and are recognized as a priority group for influenza vaccination. Despite this, uptake is often poor and one reason cited for this is concerns about safety. The objective of this study was to perform a systematic review of the safety of inactivated influenza vaccination (IIV) in pregnancy. Studies were included if they were: (i) observational or experimental design; (ii) included a comparator group comprising of unvaccinated pregnant women; (iii) comprised of either seasonal IIV or monovalent H1N1 IIV (including adjuvanted vaccines); and (iv) addressed one of the following outcomes: preterm birth (PTB), small for gestational age (SGA), fetal death (including stillbirth or spontaneous abortion), low birth weight (LBW) or congenital abnormalities. Two reviewers screened abstracts and titles and selected full texts for retrieval. Crude odds ratios were calculated from reported event rates, using binomial standard errors. Adjusted odds ratios, hazard ratios and relative rates were extracted as reported in each paper. After removal of duplicates and full text eligibility assessment, 40 studies remained. The aOR for PTB was 0.87 (0.78-0.96), for LBW 0.82 (0.76-0.89), congenital abnormality 1.03 (0.99-1.07), SGA 0.99 (0.94-1.04) and stillbirth 0.84 (0.65-1.08). This study contributes to the increasing body of safety data for IIV in pregnancy and reports a protective effect on PTB and LBW.

Keywords: immunization; influenza; pregnancy; safety; vaccination.

PubMed Disclaimer

Figures

Figure 1.
Figure 1.
PRISMA diagram. Flowchart of studies
Figure 2.
Figure 2.
Preterm birth. Adjusted Odds Ratio
Figure 3.
Figure 3.
Low birth weight. Adjusted Odds Ratio
Figure 4.
Figure 4.
Congenital abnormalities. Adjusted Odds Ratio
Figure 5.
Figure 5.
Small for gestational age. Adjusted Odds Ratio
Figure 6.
Figure 6.
Fetal death (stillbirth). Adjusted Odds Ratio
See this image and copyright information in PMC

Similar articles

See all similar articles

Cited by

See all "Cited by" articles

References

    1. Burney LE. Influenza immunization: statement. Public Health Rep. 1960;75:944. doi:10.2307/4590965. - DOI - PMC - PubMed
    1. World Health Organization The weekly epidemiological record. Geneva. 2012;87:201–216.
    1. Centers for Disease Control and Prevention Use of influenza A (H1N1) 2009 monovalent vaccine: recommendations of the Advisory Committee on Immunisation Practices (ACIP) 2009. MMWR Recomm Rep. 2009;58:1–86. - PubMed
    1. Fell DB, Bhutta ZA, Hutcheon JA, Karron RA, Knight M, Kramer MS, Monto AS, Swamy GK, Ortiz JR, Savitz DA. Report of the WHO technical consultation on the effect of maternal influenza and influenza vaccination on the developing fetus: montreal, Canada, September 30-October 1, 2015. Vaccine. 2017. April 28;35(18):2279–2287. doi:10.1016/j.vaccine.2017.03.056. - DOI - PMC - PubMed
    1. Zaman K, Roy E, Arifeen SE, Rahman M, Raqib R, Wilson E, Omer SB, Shahid NS, Breiman RF, Steinhoff MC. Effectiveness of maternal influenza immunisation in mothers and infants. N Engl J Med. 2008;359:1555–1564. doi:10.1056/NEJMoa0708630. - DOI - PubMed

Publication types

Grants and funding

This project was commissioned by the Australian Government, Office of Health Protection and contracted to the National Centre for Immunisation Research and Surveillance.