Study examines effect of receiving Tdap vaccine during pregnancy

May 3, 2014, The JAMA Network Journals

A preliminary study finds that receipt of the tetanus toxoid, reduced diphtheria toxoid, and acellular pertussis (Tdap) vaccine in the third trimester of pregnancy did not increase the risk of adverse events for the mother or infant, according to a study in the May 7 issue of JAMA, a theme issue on child health. In addition, the authors found high concentrations of pertussis antibodies in infants during the first 2 months of life, a period during which infants are at the highest risk of pertussis-associated illness or death. This issue is being released early to coincide with the Pediatric Academic Societies Annual Meeting.

Pertussis is a highly contagious and potentially fatal vaccine-preventable disease that has re-emerged in the United States despite high childhood immunization rates. Infants younger than 6 months are at greatest risk of disease, hospitalization, and death and account for more than 90 percent of all -associated deaths in the United States. Infants too young to receive the primary diphtheria and tetanus toxoids and acellular pertussis (DTaP) immunization series (recommended at 2, 4, and 6 months of age) depend on maternal antibodies for protection against pertussis. However, have very low concentrations of pertussis antibodies to transfer to their newborn at the time of delivery; maternal immunization with the Tdap vaccine could help prevent infant pertussis, according to background information in the article.

Flor M. Munoz, M.D., of the Baylor College of Medicine, Houston, and colleagues randomly assigned 48 women to receive the Tdap vaccine (n = 33) or placebo (n = 15) at 30 to 32 weeks' gestation to evaluate the safety and immunogenicity (ability to produce an immune response) of the vaccine administered during . Women who received placebo during pregnancy were given Tdap vaccine postpartum prior to hospital discharge, and women who received Tdap during pregnancy were given placebo postpartum.

The researchers found that injection site and systemic reactogenicity (adverse reactions) rates in pregnant women were not significantly different than those observed among postpartum or nonpregnant women. No Tdap-associated serious occurred in women or infants. Growth and development were similar in both infant groups. No cases of pertussis occurred.

Also, concentrations of vaccine-induced pertussis antibodies in infants born to mothers immunized with Tdap during pregnancy were significantly higher at birth and at age 2 months than in infants whose mothers were immunized postpartum.

In addition, maternal immunization with Tdap did not substantially alter infant responses to scheduled DTaP.

"Further research is needed to provide definitive evidence of the safety and efficacy of Tdap immunization during pregnancy," the authors write.

Although Tdap has an excellent safety record, future cohort or surveillance studies must continue to assess safety and immunogenicity of Tdap immunization during pregnancy, write Natalia Jimnez-Truque, M.S.C.I., Ph.D., and Kathryn M. Edwards, M.D., of Vanderbilt University Medical Center, Nashville, Tenn., in an accompanying editorial.

"Continued reporting of pertussis cases will also be necessary to assess the effectiveness of administering Tdap during pregnancy. In addition, the assessment of potential interference with DTaP and other vaccine antigens administered during infancy will require large prospective studies. Last, future research must address the safety and immunogenicity of repeated doses of Tdap during each pregnancy, because frequent immunization might lead to a blunted antibody response."

Explore further: Change increases postpartum pertussis vaccination

More information: DOI: 10.1001/jama.2014.3633
DOI: 10.1001/jama.2014.3555

Related Stories

Change increases postpartum pertussis vaccination

March 4, 2014
(HealthDay)—Changing in-hospital ordering procedures increases the postpartum pertussis vaccination rate to 69 percent, according to a study published in the March issue of the American Journal of Obstetrics & Gynecology.

Findings support safety of whooping cough vaccine for older adults

November 29, 2012
A new study of the safety of the tetanus-diphtheria-acellular pertussis (Tdap) vaccine supports the recommendation that those 65 and older get the vaccine to protect themselves and others, particularly young babies, from ...

Whole-cell vaccine was more effective than acellular vaccine during CA pertussis outbreak

May 20, 2013
Whole-cell pertussis vaccines were more effective at protecting against pertussis than acellular pertussis vaccines during a large recent outbreak, according to a new Kaiser Permanente study published in Pediatrics.

What did we learn from the 2010 California whooping cough epidemic?

July 19, 2012
Because whooping cough (pertussis) is almost as contagious as measles (affecting ~12-17 individuals with each case), clinicians are required to report cases of this bacterial respiratory tract infection to the state's department ...

Pertussis reaches epidemic level in Washington state

July 20, 2012
(HealthDay) -- Pertussis rates may reach record levels this year in the United States, where Washington state is experiencing an ongoing epidemic, according to a report published in the July 20 issue of the U.S. Centers for ...

ACIP announces recommended 2013 adult immunization schedule

January 28, 2013
The Center for Disease Control and Prevention's Advisory Committee on Immunization Practices (ACIP) announced its recommended 2013 adult immunization schedule that includes important updates to the pneumococcal, Tdap (tetanus, ...

Recommended for you

Flu may be spread just by breathing, new study shows; coughing and sneezing not required

January 18, 2018
It is easier to spread the influenza virus (flu) than previously thought, according to a new University of Maryland-led study released today. People commonly believe that they can catch the flu by exposure to droplets from ...

New approach could help curtail hospitalizations due to influenza infection

January 18, 2018
More than 700,000 Americans were hospitalized due to illnesses associated with the seasonal flu during the 2014-15 flu season, according to federal estimates. A radical new approach to vaccine development at UCLA may help ...

Certain flu virus mutations may compensate for fitness costs of other mutations

January 18, 2018
Seasonal flu viruses continually undergo mutations that help them evade the human immune system, but some of these mutations can reduce a virus's potency. According to new research published in PLOS Pathogens, certain mutations ...

Zika virus damages placenta, which may explain malformed babies

January 18, 2018
Though the Zika virus is widely known for a recent outbreak that caused children to be born with microencephaly, or having a small head, and other malformations, scientists have struggled to explain how the virus affects ...

Study reveals how MRSA infection compromises lymphatic function

January 17, 2018
Infections of the skin or other soft tissues with the hard-to-treat MRSA (methicillin-resistant Staphylococcus aureus) bacteria appear to permanently compromise the lymphatic system, which is crucial to immune system function. ...

Fresh approach to tuberculosis vaccine offers better protection

January 17, 2018
A unique platform that resulted in a promising HIV vaccine has also led to a new, highly effective vaccine against tuberculosis that is moving toward testing in humans.

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.