By Sonia Alvarado, Senior Teratogen Information Specialist, MotherToBaby CA
“I’m very confused” said the pregnant caller. “I’ve heard different things about whether I should get the vaccine against whooping cough now or after I deliver. Maybe I should just wait?” As a teratogen information specialist who talks to women and health professionals daily regarding the recommended vaccines for pregnancy, it concerns me that pregnant women are not receiving a clear message about the recommendations for vaccination against pertussis during pregnancy. How can pregnant women make informed decisions when they are not getting the correct information?
When it comes to understanding and preventing illness and injury to their children, a parent’s job starts before they hold the baby in their arms and continues for many years afterward. Before birth, parents research toys, car seats, bedding, and a number of other potential threats. High on the radar should also be preventable diseases such as pertussis, which we are hearing about much more frequently these days.
Pertussis, commonly known as “whooping cough,” is a disease caused by a bacteria, bordetella pertussis, that can spread easily through the air in infectious droplets, for example from a cough or sneeze. Although pertussis is not something that most Americans of childbearing age remember from their own childhood, pertussis harmed many children in the years before a vaccine was discovered. In the early 1900’s, 1 out of 10 children with pertussis died. When pertussis became a reportable disease in 1922, more than 100,000 cases of pertussis were reported each year.
Introduced in the late 1940’s, the pertussis vaccine has improved the health of children tremendously. The wide distribution of the vaccine since first developed meant that the numbers of infections (and deaths) from pertussis dropped dramatically. By the 1970’s, vaccination programs had been so successful that U.S. cases totaled only about 1,000 per year. Unfortunately, those historic declines have been reversed and in the past 20 years, we have seen an increase in cases rather than a decline. In 2012, over 48,000 cases of pertussis infection were reported in the U.S. which was a 60-year record high. Experts are trying to understand why the numbers of reported cases have increased. Is it due to a decrease in vaccination of children, or another reason?
Currently the pertussis vaccine comes in two forms – DTaP (Diphtheria Tetanus and Pertussis), which is the vaccine that is given in five doses to infants and children, and Tdap (Tetanus, Diphtheria and Pertussis), which is a vaccine that acts as a booster for adults and pregnant women. DTaP and Tdap are inactive vaccines and there is no chance of “catching” pertussis from the vaccination since neither contains live bacteria. While the earliest pertussis vaccines developed in the 1940’s had risks of injection site reactions such as redness and swelling, the newer forms in use today are purified (acellular) and have fewer reported side effects.
The most successful strategy for preventing pertussis in infants and children is consistent and timely vaccination of all children and adults. The Centers for Disease Control has added to this strategy by recommending that all pregnant women be vaccinated in their third trimester of pregnancy, between 27 and 36 weeks of pregnancy. Studies have shown that when women receive Tdap vaccination during the recommended time period in pregnancy, the newborn baby develops immunity through the mom’s vaccination that lasts for about two months after birth. Newborn infants are particularly vulnerable to pertussis, therefore smart vaccination interventions are needed to curb the risk to the baby.
Results of a randomized, double-blind, placebo controlled clinical trial were published in May of 2014 by Munoz, et al. The trial included 48 pregnant women who received the Tdap vaccine (33) or a placebo (15). All women received either shot at 30-32 weeks of pregnancy. The goal was to evaluate the safety of Tdap for the woman and her pregnancy as well as to determine if the vaccine would interfere with the infant’s response to the DTaP when given later in infancy. The authors found no Tdap related side effects and no other complications for mother or baby during pregnancy. Infants in both groups had similar growth and development, and reassuringly, being exposed to Tdap prior to birth did not interfere with the baby’s immune response to the DTaP series.
August is National Immunization Awareness Month and although immunizations take place daily across the country, having a specific month dedicated to vaccines gives all of us a reason to educate ourselves and others about the importance of timely vaccination and the work that is being done to understand the health benefits and any potential risks from vaccination of any group, including pregnant women. The research published to date on vaccination of pregnant women with Tdap and other vaccines including the flu shot has been reassuring and no adverse effects have been identified for either mom or the baby. Additional studies can contribute to the pool of information that is already available. MotherToBaby is conducting such a study to further understand the effects of Tdap on pregnancy. Click here to learn more.
Preventing pertussis through vaccination is similar to adding safety equipment to a pool that your own children use – as well as any neighbor children that visit. Vaccination with Tdap, particularly if you are pregnant or will be around any children, is key to preventing the damage done by this potentially fatal disease. So, just as you would talk about swimming safety with others, don’t hold your breath about pertussis. It’s air well spent to help us all breathe a bit easier!
Sonia Alvarado is a bilingual (Spanish/English) Senior Teratogen Information Specialist with MotherToBaby California, a non-profit that aims to educate women about medications and more during pregnancy and breastfeeding. Along with answering women’s and health professionals’ questions regarding exposures during pregnancy/breastfeeding via MotherToBaby’s toll-free hotline, email and private chat counseling service, she’s provided educational talks regarding pregnancy health in community clinics and high schools over the past decade.
MotherToBaby is a service of the international Organization of Teratology Information Specialists (OTIS), a suggested resource by many agencies including the Centers for Disease Control and Prevention (CDC). If you have questions about medications, vaccines, beauty products, or other exposures, call MotherToBaby toll-FREE at 866-626-6847 or visit MotherToBaby.org to browse a library of fact sheets and find your nearest affiliate.
Clark, Thomas A. (2014). Changing Pertussis Epidemiology: Everything Old is New Again. Journal of Infectious Diseases, 209;978-981. doi:10.1093/infdis/jiu001
Munoz M. Flor, MD, Bond Nanette H. PAC, Maccato Maurizio, MD, et al (2014). Safety and Immunogenity of Tetanus Diphtheria and acellular Pertussis (Tdap) Immunization during pregnancy in Mothers and Infants. JAMA, 311(17), 1760-1769. doi:10.1001/jama.2014.3633
Hirtle, P. B. (2008, July-August). Copyright renewal, copyright restoration, and the difficulty of determining copyright status. D-Lib Magazine, 14(7/8). doi:10.1045/july2008-hirtle
Centers for Disease Control and Prevention, Pertussis (Whooping Cough) http://www.cdc.gov/pertussis/about/index.html
The History of Vaccines, A Project of The College of Physicians of Philadelphia. http://www.historyofvaccines.org/content/articles/pertussis-whooping-cough