A Vaccine for Two During Pregnancy

Whooping cough vaccine given during pregnancy increased infant protection

(RxWiki News) Vaccines are designed to protect against disease, but babies cannot get most vaccines until they're two months old, leaving them vulnerable. A vaccine during pregnancy may help.

A recent study found that giving mothers a vaccine against whooping cough during pregnancy increased their babies' protection against the disease after birth.

The vaccine is called Tdap, which stands for tetanus, diphtheria and acellular pertussis. Pertussis is another name for whooping cough.

The newborns whose mothers received the Tdap during pregnancy had more antibodies (disease-fighting proteins) against pertussis than the babies of mothers who received the Tdap after giving birth.

"Ask your OB/GYN about the Tdap during pregnancy."

This study, led by Flor Munoz, MD, of the Departments of Pediatrics and Molecular Virology and Microbiology at Baylor College of Medicine in Houston, Texas, looked at the safety of the Tdap during pregnancy.

The researchers also looked at the immune response that resulted from the vaccine in pregnant women and how infants' bodies responded.

The researchers gave 33 women the Tdap vaccine when they were 30 to 32 weeks pregnant.

Another 15 women received a placebo (not the real Tdap) injection at 30 to 32 weeks of pregnancy and then received the Tdap after giving birth.

Then the researchers looked for possible negative side effects and the babies' growth through 13 months old.

These researchers also looked at the antibodies present in the mothers' and babies' bodies in response to the vaccine.

A vaccine works by imitating the real disease to cause the body to create the antibodies that would normally be used to fight off that disease.

None of the women or the babies experienced any serious negative side effects from the vaccine, although most of the women had soreness or redness at the injection site.

The growth and development of the babies in both groups was similar, regardless of whether the mother had received the Tdap before or after giving birth.

None of the women or their children caught pertussis.

When the researchers measured the antibodies in the women at the time of giving birth, they found a much higher concentration of antibodies against pertussis in the women who received the vaccine prenatally (before birth) than in those who received it after giving birth.

The newborns of the women who got the vaccine during pregnancy also showed a higher concentration of antibodies than that of the other women's newborns — almost five times higher.

Even at 2 months old, the antibody concentration in the newborns of mothers who received the vaccine before birth was four times greater than the antibody concentration in babies whose mothers received the vaccine postpartum (after birth).

After all the children had received their fourth dose of DTaP, the infant version of the vaccine typically given between 12 and 18 months old, the antibodies in the children were all about the same.

The researchers concluded that giving the mothers Tdap during pregnancy did not decrease the effectiveness of the DTaP given to babies later on.

Further, the researchers did not find adverse events from the vaccine, though the study was too small to determine whether this would be true in a larger group.

Also, "maternal immunization with Tdap resulted in high concentrations of pertussis antibodies in infants during the first 2 months of life," the researchers wrote.

This study was published May 3 in JAMA. The research was funded by the National Institute of Allergy and Infectious Diseases, the National Institutes of Health, the National Center for Research Resources and the National Center for Advancing Translational Sciences.

Six of the authors reported various consulting, research, speaking or travel funding received from various pharmaceutical companies, including Sanofi Pasteur, Novartis, GlaxoSmithKline, Gilead, Chimerix, Roche, Pfizer, Abbvie, Novavax, Hoffmann-LaRoche and Merck.

Review Date: 
May 2, 2014