1
|
Regan AK, Sullivan SG, Arah OA. Maternal influenza vaccination and associated risk of fetal loss: A claims-based prospective cohort study. Vaccine 2024; 42:126256. [PMID: 39260053 PMCID: PMC11911014 DOI: 10.1016/j.vaccine.2024.126256] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2024] [Revised: 07/26/2024] [Accepted: 08/20/2024] [Indexed: 09/13/2024]
Abstract
BACKGROUND Although numerous studies support the safety of influenza vaccination during pregnancy, fewer studies have evaluated the risk of miscarriage or considered the effect of prior immunization. METHODS Using national de-identified administrative claims data from the Optum Labs Data Warehouse, we conducted a claims-based cohort study of 117,626 pregnancies between January 2009 and December 2018. We identified pandemic A(H1N1)pdm09 and seasonal influenza vaccinations using CPT codes. Fetal loss was defined as miscarriage, medical termination, or stillbirth as identified by ICD-10-CM diagnostic codes. Cox proportional hazard models treating influenza vaccination as a time-varying exposure, weighted for loss-to-follow-up and stratified by baseline probability of vaccination, were used to model the risk of fetal loss by exposure to influenza vaccine. RESULTS About 31.4 % of the cohort had a record of influenza vaccination; 10.0 % were vaccinated before pregnancy only, 17.8 % during pregnancy only, and 3.6 % before and during pregnancy. The risk of miscarriage was 39 % lower among those vaccinated during pregnancy compared to unvaccinated (adjusted hazard ratio, aHR 0.61; 95 % CI 0.50, 0.74) and was similar for medical termination or stillbirth (HR 0.69; 95 % CI 0.45, 1.03 and aHR 0.99; 95 % CI 0.76, 1.30, respectively). Similar results were observed for women who received the vaccine before and during pregnancy. We observed little to no association between vaccination before pregnancy and risk of miscarriage (HR 0.98; 95 % CI 0.76, 1.26), medical termination (HR 1.02; 95 % CI 0.46, 2.24), or stillbirth (HR 1.14, 95 % CI 0.77, 1.69). DISCUSSION Influenza vaccination was not associated with an increased risk of fetal loss. These results support the safety of influenza vaccine administration even when administered before or early during pregnancy.
Collapse
Affiliation(s)
- Annette K Regan
- School of Nursing and Health Professions, University of San Francisco, San Francisco, CA, United States; Department of Epidemiology, Fielding School of Public Health, UCLA, Los Angeles, CA, United States.
| | - Sheena G Sullivan
- Department of Epidemiology, Fielding School of Public Health, UCLA, Los Angeles, CA, United States; WHO Collaborating Centre for Reference and Research on Influenza, Royal Melbourne Hospital, and Department of Infectious Diseases, University of Melbourne, at the Peter Doherty Institute for Infection and Immunity, Melbourne, VIC, Australia
| | - Onyebuchi A Arah
- Department of Epidemiology, Fielding School of Public Health, UCLA, Los Angeles, CA, United States; Department of Statistics and Data Science, UCLA, Los Angeles, CA, United States; Practical Causal Inference Lab, UCLA, Los Angeles, CA, United States; Department of Public Health, Research Unit for Epidemiology, Aarhus University, Aarhus, Denmark
| |
Collapse
|
2
|
Romano CJ, Hall C, Khodr ZG, Bukowinski AT, Gumbs GR, Conlin AMS. History of pandemic H1N1-containing influenza vaccination and risk for spontaneous abortion and birth defects. Vaccine 2021; 39:6553-6562. [PMID: 34598819 DOI: 10.1016/j.vaccine.2021.09.003] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2021] [Revised: 08/25/2021] [Accepted: 09/01/2021] [Indexed: 10/20/2022]
Abstract
BACKGROUND One recent study suggested an association between receipt of pandemic H1N1 (pH1N1)-containing vaccines in consecutive influenza seasons and spontaneous abortion, but corroborating scientific evidence is limited. In the present study, we leveraged a population of vaccine-compliant pregnant military women to examine history of pH1N1-containing influenza vaccination and adverse pregnancy outcomes. Because seasonal influenza vaccination is compulsory for military service, safety concerns regarding repeat vaccination are particularly relevant in this population. METHODS Pregnancies and live births from Department of Defense Birth and Infant Health Research program data were linked with military personnel immunization records to identify women vaccinated with a pH1N1-containing vaccine in pregnancy prior to 21 6/7 weeks' gestation, October 2009-April 2015. Cox and modified Poisson regression models estimated associations between vaccination with pH1N1- versus non-pH1N1-containing influenza vaccine in the season prior to the index pregnancy, and spontaneous abortion and birth defects, respectively. Cox models were calculated for two periods of follow-up: through (1) 21 6/7 weeks' gestation and (2) 28 days postvaccination. RESULTS Of 26,264 pregnancies, 21,736 (82.8%) were among women who received a dose of pH1N1-containing vaccine in the prior influenza season and 4,528 (17.2%) were among women who received non-pH1N1-containing vaccine in the prior influenza season. Among 23,121 infants, 19,365 (83.8%) and 3,756 (16.2%) had mothers exposed and unexposed to pH1N1-containing vaccine in the prior influenza season, respectively. The adjusted hazard ratio (aHR) for spontaneous abortion approximated 1.0 across the complete follow-up period (95% confidence interval [CI]: 0.89-1.13) and was slightly elevated when censored at 28 days postvaccination, though the CI was imprecise (aHR: 1.19; 95% CI: 0.97-1.46). No associations with birth defects were observed. CONCLUSION This work lends additional safety evidence and support for vaccination against pH1N1 in pregnancy, regardless of the vaccine received in the prior influenza season.
Collapse
Affiliation(s)
- Celeste J Romano
- Deployment Health Research Department, Naval Health Research Center, 140 Sylvester Road, San Diego, CA 92106, USA; Leidos, Inc., 140 Sylvester Road, San Diego, CA 92106, USA.
| | - Clinton Hall
- Deployment Health Research Department, Naval Health Research Center, 140 Sylvester Road, San Diego, CA 92106, USA; Leidos, Inc., 140 Sylvester Road, San Diego, CA 92106, USA
| | - Zeina G Khodr
- Deployment Health Research Department, Naval Health Research Center, 140 Sylvester Road, San Diego, CA 92106, USA; Leidos, Inc., 140 Sylvester Road, San Diego, CA 92106, USA
| | - Anna T Bukowinski
- Deployment Health Research Department, Naval Health Research Center, 140 Sylvester Road, San Diego, CA 92106, USA; Leidos, Inc., 140 Sylvester Road, San Diego, CA 92106, USA
| | - Gia R Gumbs
- Deployment Health Research Department, Naval Health Research Center, 140 Sylvester Road, San Diego, CA 92106, USA; Leidos, Inc., 140 Sylvester Road, San Diego, CA 92106, USA
| | - Ava Marie S Conlin
- Deployment Health Research Department, Naval Health Research Center, 140 Sylvester Road, San Diego, CA 92106, USA
| |
Collapse
|
3
|
Buchy P, Badur S, Kassianos G, Preiss S, Tam JS. Vaccinating pregnant women against influenza needs to be a priority for all countries: An expert commentary. Int J Infect Dis 2019; 92:1-12. [PMID: 31863875 DOI: 10.1016/j.ijid.2019.12.019] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2019] [Revised: 12/12/2019] [Accepted: 12/13/2019] [Indexed: 10/25/2022] Open
Abstract
BACKGROUND In 2012, the World Health Organization recommended influenza vaccination for all pregnant women worldwide and the prioritisation of pregnant women in national influenza vaccination programmes. Nevertheless, vaccination rates in pregnant women often remain much lower than national targets. OBJECTIVES To assess the benefits and risks associated with influenza infection and vaccination during pregnancy, and to consider obstacles that work against influenza vaccine uptake during pregnancy. RESULTS There is strong evidence that maternal and foetal outcomes can be compromised if women develop influenza infections during pregnancy. Influenza vaccines have been administered to millions of pregnant women and have demonstrated benefits in terms of disease prevention in mothers and their infants. There is a consensus amongst several recommending authorities that influenza vaccines may be safely administered during all stages of pregnancy. Healthcare professionals are recognised as the most important influencers of vaccine uptake, being well placed to recommend vaccination and directly address safety concerns. CONCLUSIONS Despite data supporting the value of influenza vaccination during pregnancy, vaccine uptake remains low globally. Low uptake appears to be largely due to ineffective communication with pregnant women about the risks and benefits of influenza vaccination. A graphical abstract is available online.
Collapse
Affiliation(s)
| | - Selim Badur
- GSK, Büyükdere Caddesi No:173 1. Levent Plaza B Blok, 34394 Istanbul, Turkey
| | - George Kassianos
- President of the British Global & Travel Health Association, Chairman of RAISE Pan- European Committee on Influenza, National Immunisation Lead Royal College of General Practitioners, United Kingdom, Board Director of the European Working Group on Influenza
| | | | - John S Tam
- Chairman of the Asia Pacific Alliance for the control of influenza (APACI); Adjunct Professor, Department of Applied Biology and Chemical Technology, Hong Kong Polytechnic University, 11 Yuk Choi Rd, Hung Hom, Hong Kong
| |
Collapse
|
4
|
Brillo E, Tosto V, Giardina I, Buonomo E. Maternal tetanus, diphtheria, and acellular pertussis (Tdap) and influenza immunization: an overview. J Matern Fetal Neonatal Med 2019; 34:3415-3444. [PMID: 31645152 DOI: 10.1080/14767058.2019.1680633] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
BACKGROUND Maternal tetanus, diphtheria, and acellular pertussis (Tdap) and influenza immunization for women during pregnancy (the so-called "maternal immunization") has been introduced in several countries, and recently also in Italy, to protect mother and fetus during pregnancy, infant in his first months of life and mother during postpartum period. However, very low vaccination coverage rates have been reached due to several variables. METHODS A literature search was conducted on PubMed and Embase, including any experimental or observational studies, to assesses existing evidence on the effectiveness, efficacy, safety and optimal timing of administration of Tdap and influenza immunization in pregnancy for mothers and their infants. The search was finalized in August 2019. RESULTS Reviewing the literature, we identified only a few studies that, among several maternal and infant outcomes, found sporadic significant associations with maternal influenza immunization and even less with Tdap immunization. Moreover, most of the authors of these studies explained these findings as a result of residual confounding effect. The effectiveness of maternal influenza immunization is more complicated to prove than the effectiveness of Tdap immunization because of several reasons. Not all nations recommend and offer vaccines in the same weeks of pregnancy and this one manifests the complexity in defining the best timing for Tdap or influenza immunization. CONCLUSIONS The safety of maternal Tdap or influenza immunization is supported by the evidence so far, however, regular surveillance should be maintained, especially with regard to the influenza vaccine that changes in formulation each year. There is a need to optimize the timing of vaccination in pregnancy and to have a national system of detection of maternal immunization in each country.
Collapse
Affiliation(s)
- Eleonora Brillo
- Center for Research in Perinatal and Reproductive Medicine, University of Perugia, Perugia, Italy.,Department of Biomedicine and Prevention, University of Rome "Tor Vergata", Rome, Italy
| | - Valentina Tosto
- Department of Obstetrics and Gynecology, University Hospital of Perugia, Perugia, Italy
| | - Irene Giardina
- Center for Research in Perinatal and Reproductive Medicine, University of Perugia, Perugia, Italy.,Department of Obstetrics and Gynecology, University Hospital of Perugia, Perugia, Italy
| | - Ersilia Buonomo
- Department of Biomedicine and Prevention, University of Rome "Tor Vergata", Rome, Italy
| |
Collapse
|
5
|
Sullivan SG, Price OH, Regan AK. Burden, effectiveness and safety of influenza vaccines in elderly, paediatric and pregnant populations. Ther Adv Vaccines Immunother 2019; 7:2515135519826481. [PMID: 30793097 PMCID: PMC6376509 DOI: 10.1177/2515135519826481] [Citation(s) in RCA: 45] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2018] [Accepted: 12/20/2018] [Indexed: 11/17/2022] Open
Abstract
Vaccination is the most practical means available for preventing influenza. Influenza vaccines require frequent updates to keep pace with antigenic drift of the virus, and the effectiveness, and sometimes the safety, of the vaccine can therefore vary from season to season. Three key populations that the World Health Organization recommends should be prioritized for influenza vaccination are pregnant women, children younger than 5 years of age and the elderly. This review discusses the burden of influenza and the safety and effectiveness profile of influenza vaccines recommended for these groups.
Collapse
Affiliation(s)
- Sheena G. Sullivan
- WHO Collaborating Centre for Reference and Research on Influenza, Peter Doherty Institute for Infection and Immunity, 792 Elizabeth St, Melbourne, Victoria 3000, Australia
- School of Population and Global Health, University of Melbourne, Australia Fielding School of Public Health, University of California, Los Angeles, CA, USA
| | - Olivia H. Price
- WHO Collaborating Centre for Reference and Research on Influenza, Peter Doherty Institute for Infection and Immunity, Melbourne, Victoria, Australia
| | - Annette K. Regan
- School of Public Health, Texas A&M University, College Station, TX, United States; School of Public Health, Curtin University, Perth, Western Australia, Australia, and Wesfamers Centre of Vaccines and Infectious Diseases, Telethon Kids Institute, Crawley, Western Australia, Australia
| |
Collapse
|
6
|
|
7
|
Abstract
Maternal immunization for prevention of morbidity and mortality of pregnant women and their neonates due to infectious diseases is ongoing worldwide. The complexity of vaccine research and development in this population is challenging. Not only do vaccines for pregnant women require evidence of immunogenicity, potency, stability, and limited reactogenicity, they must also provide efficacy in decreasing morbidity for the pregnant woman, her fetus, and the neonate, demonstrate safety or lack of evidence of harm, and offer benefit or potential benefit of vaccination during pregnancy. Since the 19th century, evidence of protective effects of vaccination during pregnancy has been documented. Pandemic influenza and pertussis outbreaks in recent years have affected a paradigm shift in vaccine research and development as well as current policy regarding immunization in pregnancy. Studies of the immune system in pregnant women and neonates have shown that immune changes associated with pregnancy in women do not interfere with maternal vaccine responses, multiple factors are important in transplacental transfer of antibodies, and maternal antibodies are beneficial to neonates. In recent years, guidelines have been developed by expert panels to help design studies for maternal vaccinations and for harmonization of data collection, analysis, and adverse event reporting. Further research into maternal and neonatal immunology, transplacental antibody transfer, and epidemiology of diseases is needed, especially as new vaccines to respiratory syncytial virus, cytomegalovirus, and Group B streptococcus are developed. Maternal vaccinations have the potential to change the epidemiology of infectious diseases in reproductive health and pediatrics and may lead to new clinical applications to improve global maternal and neonatal health.
Collapse
Affiliation(s)
- Alisa Kachikis
- 1 Department of Obstetrics and Gynecology, University of Washington , Seattle, Washington
| | - Linda O Eckert
- 1 Department of Obstetrics and Gynecology, University of Washington , Seattle, Washington.,2 Department of Global Health, University of Washington , Seattle, Washington
| | - Janet Englund
- 3 Department of Pediatrics, Pediatric Infectious Diseases, Seattle Children's Hospital, University of Washington , Seattle, Washington
| |
Collapse
|