Efficacy and safety of influenza vaccination during pregnancy: realizing the potential of maternal influenza immunization

ABSTRACT

Introduction: Pregnant women are at higher risk of severe complications following influenza infection compared to the general population. Influenza vaccination during pregnancy can offer direct protection to pregnant women and passive immunity to infants up to 6 months of age via maternal antibodies. Pregnant women are a high priority group for influenza immunization.

Areas covered: This review provides an overview of the basis for recommending influenza vaccine to pregnant women, current immunization policies, the evidence supporting the safety and effectiveness of maternal vaccination, and future research needed. We conducted a search of PubMed for articles describing the safety or efficacy of influenza vaccines administered during pregnancy. Published articles from inception to 17 November 2020 were reviewed.

Expert opinion: Experimental and observational evidence support the efficacy, effectiveness and safety of influenza immunization during pregnancy. These data support the continued provision of inactivated influenza vaccine to pregnant women, as recommended by global immunization policies. To achieve success with maternal influenza immunization programs, further work is needed to inform policy development in low- and middle-income settings and implementation and promotion in high-income settings.

KEYWORDS:

• Influenza
• influenza vaccines
• maternal vaccination
• pregnancy
• preventive health

Article highlights

• Severe influenza illness is more common among pregnant women and infants <6 months old.

• Evidence from clinical trials shows that influenza vaccination during pregnancy protects against two-thirds of infant infections and more than one-third of maternal infections, and protects against severe disease.

• Experimental and observational evidence supports the safety of vaccination during pregnancy.

• Influenza vaccination rates are low among pregnant women, and in order for pregnant women and their infants to receive the benefits of maternal influenza vaccination, evidence-based interventions are needed to improve immunization rates.

• With decades of prior experience with maternal influenza immunization and new and emerging viral threats to the health of pregnant women, we can apply such experiences to inform future maternal vaccination programs.

Declaration of interest

The authors have no relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript. This includes employment, consultancies, honoraria, stock ownership or options, expert testimony, grants or patents received or pending, or royalties.

Reviewer disclosures

A reviewer on this manuscript has disclosed that they are a writer for Up To Date and a consultant to GSK for the CMV vaccine. Peer reviewers on this manuscript have no relevant financial or other relationships to disclose.

Additional information

Funding

This paper was not funded.