0
We're unable to sign you in at this time. Please try again in a few minutes.
Retry
We were able to sign you in, but your subscription(s) could not be found. Please try again in a few minutes.
Retry
There may be a problem with your account. Please contact the AMA Service Center to resolve this issue.
Contact the AMA Service Center:
Telephone: 1 (800) 262-2350 or 1 (312) 670-7827  *   Email: subscriptions@jamanetwork.com
Error Message ......
Original Investigation |

Duration of Infant Protection Against Influenza Illness Conferred by Maternal Immunization Secondary Analysis of a Randomized Clinical Trial

Marta C. Nunes, PhD1,2; Clare L. Cutland, MD1,2; Stephanie Jones, MD1,2; Andrea Hugo, MD1,2; Richard Madimabe, BTech1,2; Eric A. F. Simões, MD2,3; Adriana Weinberg, MD4; Shabir A. Madhi, MD, PhD1,2,5 ; for the Maternal Flu Trial Team
[+] Author Affiliations
1Department of Science and Technology/National Research Foundation, Vaccine Preventable Diseases, University of the Witwatersrand, Johannesburg, South Africa
2Medical Research Council, Respiratory and Meningeal Pathogens Research Unit, Chris Hani Baragwanath Hospital, University of the Witwatersrand, Johannesburg, South Africa
3Department of Pediatrics, University of Colorado and Center for Global Health, Aurora
4Departments of Pediatrics, Medicine, and Pathology, University of Colorado, Aurora
5National Institute for Communicable Diseases, Division of National Health Laboratory Service, Centre for Vaccines and Immunology, Johannesburg, South Africa
JAMA Pediatr. 2016;170(9):840-847. doi:10.1001/jamapediatrics.2016.0921.
Text Size: A A A
Published online

Importance  Influenza immunization of women during pregnancy protects the young infants against influenza illness. The duration of this protection remains unclear.

Objective  To evaluate the duration of infant protection conferred by maternal immunization and its association with transplacental antibody transfer.

Design, Setting, and Participants  Infants born to women who participated in a randomized, double-blind, placebo-controlled clinical trial in 2011 and 2012 on the safety, immunogenicity, and efficacy of trivalent inactivated influenza vaccine (IIV3) during pregnancy were followed up during the first 6 months of life for polymerase chain reaction (PCR)–confirmed influenza illness. In a secondary analysis of a subset of infants, hemagglutination inhibition (HAI) antibodies were measured. The study was performed at a single center in South Africa. The secondary analysis was performed in October 2014.

Exposure  Maternal immunization for influenza.

Main Outcomes and Measures  The vaccine’s efficacy against PCR-confirmed influenza illness and the percentage of infants with HAI titers of 1:40 or more by age group.

Results  There were 1026 infants (47.2% female) born to IIV3 recipients and 1023 infants (47.3% female) born to placebo recipients who were included in the analysis of the vaccine’s efficacy. The vaccine’s efficacy against PCR-confirmed influenza illness was highest among infants 8 weeks of age or younger at 85.6% (95% CI, 38.3%-98.4%) and decreased with increasing age to 25.5% (95% CI, −67.9% to 67.8%) among infants 8 to 16 weeks of age and to 30.3% (95% CI, −154.9% to 82.6%) among infants 16 to 24 weeks of age. Similarly, in the IIV3 group, the percentage of infants with HAI titers of 1:40 or more to the influenza vaccine strains decreased from more than 56% in the first week of life to less than 40% at 16 weeks of age and less than 10.0% at 24 weeks of age.

Conclusions and Relevance  Maternal immunization conferred protection against infection in the infants for a limited period during early life. The lack of protection beyond 8 weeks of age correlated with a decrease in maternally derived antibodies.

Trial Registration  clinicaltrials.gov Identifier: NCT01306669

Figures in this Article

Sign in

Purchase Options

• Buy this article
• Subscribe to the journal
• Rent this article ?

Figures

Place holder to copy figure label and caption
Figure 1.
Flow Diagram Representing the Number of Infants Analyzed at the Different Immunogenicity Visits

Participants were excluded from the analysis for the relevant strain from the current visit onward. A laboratory-confirmed episode of influenza illness (confirmed by serology or polymerase chain reaction) occurred in the interval between the previous visit and the current visit. IIV3 indicates trivalent inactivated influenza vaccine.

Graphic Jump Location
Place holder to copy figure label and caption
Figure 2.
Percentage of Infants With Hemagglutination Inhibition Titers of 1:40 or More at the Different Study Time Points

The error bars indicate 95% CIs. HAI, indicates hemagglutination inhibition; IIV3, trivalent inactivated influenza vaccine.

Graphic Jump Location

Tables

References

Correspondence

CME
Also Meets CME requirements for:
Browse CME for all U.S. States
Accreditation Information
The American Medical Association is accredited by the Accreditation Council for Continuing Medical Education to provide continuing medical education for physicians. The AMA designates this journal-based CME activity for a maximum of 1 AMA PRA Category 1 CreditTM per course. Physicians should claim only the credit commensurate with the extent of their participation in the activity. Physicians who complete the CME course and score at least 80% correct on the quiz are eligible for AMA PRA Category 1 CreditTM.
Note: You must get at least of the answers correct to pass this quiz.
Please click the checkbox indicating that you have read the full article in order to submit your answers.
Your answers have been saved for later.
You have not filled in all the answers to complete this quiz
The following questions were not answered:
Sorry, you have unsuccessfully completed this CME quiz with a score of
The following questions were not answered correctly:
Commitment to Change (optional):
Indicate what change(s) you will implement in your practice, if any, based on this CME course.
Your quiz results:
The filled radio buttons indicate your responses. The preferred responses are highlighted
For CME Course: A Proposed Model for Initial Assessment and Management of Acute Heart Failure Syndromes
Indicate what changes(s) you will implement in your practice, if any, based on this CME course.

Multimedia

Some tools below are only available to our subscribers or users with an online account.

3,592 Views
0 Citations
×

Sign in

Purchase Options

• Buy this article
• Subscribe to the journal
• Rent this article ?

Related Content

Customize your page view by dragging & repositioning the boxes below.

See Also...
Articles Related By Topic
Related Collections
PubMed Articles
Jobs
JAMAevidence.com

The Rational Clinical Examination: Evidence-Based Clinical Diagnosis
Influenza

The Rational Clinical Examination: Evidence-Based Clinical Diagnosis
Make the Diagnosis: Influenza

brightcove.createExperiences();