Acrobat
MS Word
PowerPoint
Volume 6, No. 11, November 2008
Abstract of the Month
Effectiveness of maternal influenza immunization in mothers and infants
BACKGROUND: Young infants and pregnant women are at increased risk for serious consequences of influenza infection. Inactivated influenza vaccine is recommended for pregnant women but is not licensed for infants younger than 6 months of age. We assessed the clinical effectiveness of inactivated influenza vaccine administered during pregnancy in Bangladesh. METHODS: In this randomized study, we assigned 340 mothers to receive either inactivated influenza vaccine (influenza-vaccine group) or the 23-valent pneumococcal polysaccharide vaccine (control group). Mothers were interviewed weekly to assess illnesses until 24 weeks after birth. Subjects with febrile respiratory illness were assessed clinically, and ill infants were tested for influenza antigens. We estimated the incidence of illness, incidence rate ratios, and vaccine effectiveness.
RESULTS: Mothers and infants were observed from August 2004 through December 2005. Among infants of mothers who received influenza vaccine, there were fewer cases of laboratory-confirmed influenza than among infants in the control group (6 cases and 16 cases, respectively), with a vaccine effectiveness of 63% (95% confidence interval [CI], 5 to 85). Respiratory illness with fever occurred in 110 infants in the influenza-vaccine group and 153 infants in the control group, with a vaccine effectiveness of 29% (95% CI, 7 to 46). Among the mothers, there was a reduction in the rate of respiratory illness with fever of 36% (95% CI, 4 to 57).
CONCLUSIONS: Inactivated influenza vaccine reduced proven influenza illness by 63% in infants up to 6 months of age and averted approximately a third of all febrile respiratory illnesses in mothers and young infants. Maternal influenza immunization is a strategy with substantial benefits for both mothers and infants.
Zaman K, Roy E, Arifeen SE,
Rahman M, Raqib R, Wilson E, Omer SB, Shahid NS, Breiman RE, Steinhoff MC. Effectiveness
of maternal influenza immunization in mothers and infants. N Engl J Med. 2008
Oct 9;359(15):1555-64. Epub 2008 Sep 17.
http://www.ncbi.nlm.nih.gov/pubmed/18799552
Free Full Text:
http://content.nejm.org/cgi/content/full/359/15/1555
OB/GYN CCC Editorial comment:
This article is important because it demonstrates another way that flu vaccine can be used to protect some of the most vulnerable amongst us. In addition to conferring protection to the mothers in this study (who experienced a 36% reduction in febrile respiratory illness), the infants born to the mothers who received influenza vaccine had 63% fewer cases of influenza than the infants born to the control group of mothers. The infants also experienced 29% fewer febrile respiratory illnesses overall. Influenza vaccine is not currently licensed for use in infants younger than 6 months of age. Their best protections are for their mothers to receive a flu shot in pregnancy and for the household contacts of infants to be immunized as well.
In an article about the study published by Johns Hopkins, the authors of the
study observed:
“Even though there is no flu vaccine for these children, our study shows
that a newborn’s risk of infection can be greatly reduced by vaccinating
mom during pregnancy. It’s a two for one benefit,” said Mark Steinhoff,
MD, the study’s senior author and professor in the Bloomberg School’s
Department of International Health. “Infants under six months have the
highest rates of hospitalization from influenza among children in the U.S. These
admission rates are higher than those for the elderly and other high-risk adult
groups.”
AWHONN (the Association of Women’s Health, Obstetric, and Neonatal Nurses)
is publicizing the results of a new national survey, conducted on behalf of the
national Women’s Health Resource Center (NWHRC), which demonstrated that
only 20 percent of those currently pregnant planned to get a flu shot this season.
AWHONN has launched a campaign, Flu-Free & Mom To Be; Protect Yourself,
Protect Your Baby—Get a Flu Shot!, to encourage influenza vaccination
for pregnant women and new mothers.
Is your facility currently offering flu shots to pregnant women? Do you have
standing orders to make this a streamlined, efficient process? What about vaccinating
the rest of the household? Can partners, older siblings, and grandparents easily
receive a flu shot at your facility? If not, then take time to develop strategies
to meet this need right away. It’s still early enough in flu season for
these interventions to make a real difference.
You will find resources for flu season throughout this issue. The Indian Child Health notes also address influenza vaccination, as do other items in the “Features” section from ACOG, the Featured Website section and the Patient Education section. And in the “From Your Colleagues” section you’ll find encouragement from Public Health Service leadership for you to get your own flu shot if you haven’t already.
Help someone get vaccinated today!
AWHONN website:
http://www.awhonn.org/awhonn/content.do?name=02_PracticeResources/2B1_FluFreeMom2Be.htm
2008 CDC Influenza Vaccination Guidelines:
The 2008 recommendations include:
Vaccination of all children aged 6 months–18 years should begin before or during the 2008–09 influenza season if feasible, but no later than during the 2009–10 influenza season. Vaccination of all children aged 5–18 years is a new ACIP recommendation.
Children and adolescents at high risk for influenza complications should continue to be a focus of vaccination efforts as providers and programs transition to routinely vaccinating all children and adolescents. Recommendations for these children have not changed. Children and adolescents at higher risk for influenza complication are those:
- aged 6 months–4 years;
- who have chronic pulmonary (including asthma), cardiovascular (except hypertension), renal, hepatic, hematological or metabolic disorders (including diabetes mellitus);
- who are immunosuppressed (including immunosuppression caused by medications or by human immunodeficiency virus);
- who have any condition (e.g., cognitive dysfunction, spinal cord injuries, seizure disorders, or other neuromuscular disorders) that can compromise respiratory function or the handling of respiratory secretions or that can increase the risk for aspiration;
- who are receiving long-term aspirin therapy who therefore might be at risk for experiencing Reye syndrome after influenza virus infection;
- who are residents of chronic-care facilities; and,
- who will be pregnant during the influenza season.
Annual recommendations for adults have not changed. Annual vaccination against influenza is recommended for any adult who wants to reduce the risk for becoming ill with influenza or of transmitting it to others. Vaccination also is recommended for all adults in the following groups, because these persons are either at high risk for influenza complications, or are close contacts of persons at higher risk:
- persons aged >50 years;
- women who will be pregnant during the influenza season;
- persons who have chronic pulmonary (including asthma), cardiovascular (except hypertension), renal, hepatic, hematological or metabolic disorders (including diabetes mellitus);
- persons who have immunosuppression (including immunosuppression caused by medications or by human immunodeficiency virus);
- persons who have any condition (e.g., cognitive dysfunction, spinal cord injuries, seizure disorders, or other neuromuscular disorders) that can compromise respiratory function or the handling of respiratory secretions or that can increase the risk for aspiration;
- residents of nursing homes and other chronic-care facilities;
- health-care personnel;
- household contacts and caregivers of children aged <5 years and adults aged >50 years, with particular emphasis on vaccinating contacts of children aged <6 months; and,
- household contacts and caregivers of persons with medical conditions that put them at high risk for severe complications from influenza.
Centers for Disease Control and Prevention. Prevention and Control of Influenza; Recommendations of the Advisory Committee on Immunization Practices (ACIP), 2008. MMWR 2008;57(No. RR-7). http://www.cdc.gov/mmwr/PDF/rr/rr5707.pdf
Immunization in Pregnancy Chart:
http://www.cdc.gov/vaccines/pubs/downloads/f_preg_chart.pdf
Contents Summary ‹ Previous | Next › From Your Colleagues
OB/GYN
Jean Howe, MD, MPH is the Obstetrics and Gynecology Chief Clinical Consultant (OB/GYN C.C.C.). Dr. Howe is very interested in establishing a dialogue and/or networking with anyone involved in women's health or maternal child health, especially as it applies to American Indian and Alaska Native women and also indigenous peoples around the world. Please don't hesitate to contact her by e-mail (jean.howe@ihs.gov) or phone at (928) 674-7422.
