Commentary - August 2008
By C. Mary Healy, MD
The Center for Vaccine Awareness and Research at Texas Children's Hospital in Houston has begun implementing the "Cocoon Strategy" vaccination program, which protects young infants from the life-threatening infection pertussis or whooping cough. The "cocoon" is created by immunizing the mother after a baby's delivery and before hospital discharge and all household contacts or care providers with a pertussis-containing vaccine.
This Cocoon Strategy has been recommended by the Centers for Disease Control and Prevention (CDC) since 2006, but it is not routinely used in health care organizations. This intervention is very important because research shows that infants who are too young to have completed their primary series of immunizations, given at 2, 4, and 6 months, are at the highest risk of becoming infected with pertussis; these infants also have high rates of hospitalization and complications from the disease.
Since 1990, 87 to 100 percent of pertussis-related deaths in the United States have occurred in infants younger than 6 months. Research also shows that in 75 percent of cases, the infant gets pertussis from someone who lives in their household, most commonly the mother. In addition, pertussis incidence and mortality are higher in infants of Hispanic ethnicity, for reasons that are not completely understood.
The Cocoon Strategy aims to protect newborn infants from becoming infected with pertussis by administering Tdap (tetanus, diphtheria, and acellular pertussis) booster vaccines to mothers and family members (aged 11 to 66 years) of newborn infants. In this way, mothers and family members are protected from getting pertussis and passing it on to their young infants.
The Center for Vaccine Awareness and Research will administer Tdap booster vaccine to approximately 5,800 families at Houston's Ben Taub General Hospital (BTGH), administering vaccine to 17,400 persons in the first year. This will indirectly impact innumerable other persons because preventing pertussis in vaccinated people has the effect of reducing transmission to others who are susceptible.
The Cocoon Strategy involves first educating the mother and her family about pertussis and the Tdap vaccine before administering the Tdap booster vaccine. The program team, working in collaboration with BTGH staff, is prepared to communicate with families in English and Spanish.
Phase 1 of this program was initiated in January and involved immunizing postpartum mothers before hospital discharge. Phase 2, which will be in operation shortly, will provide Tdap immunizations for mothers and two other family members before the mother and infant are discharged from the hospital.
Results to Date
In the three months since the program was launched, approximately 1,100 postpartum women have received Tdap vaccine, and many more have received education about this illness and ways to prevent it. There were no reported moderate or serious vaccine-related side effects in any mother.
Ninety-three percent of immunized mothers were of Hispanic ethnicity; other reported ethnic groups included black (4.7 percent), white (0.9 percent), Asian (0.9 percent), Native American (0.3 percent), and others (0.3 percent). Forty-six percent of mothers were between 20 and 29 years of age. In addition to postpartum women, three women received Tdap after miscarriage, five after a stillbirth, and one after being readmitted with a wound infection.
The vaccination program has been well received by both staff and patients. Where Tdap vaccine was not given to a postpartum woman, the most common reason was recent receipt of Td (tetanus-diphtheria) vaccine.
Since the Cocoon Strategy was initiated, midwives in the antenatal clinic of the hospital have deferred Td vaccine in pregnancy in favor of postpartum Tdap, as recommended by the CDC.
Dr. Healy is director of vaccinology and maternal Immunization in the Center for Vaccine Awareness and Research, Texas Children's Hospital in Houston.
Editor's Note: For more information on immunization efforts in Texas, see " Shots for Big Tots ."
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