**3.5. Caregivers: cocooning strategy**

and 36 weeks of gestation in all pregnancies (not just the first one). Vaccination of the pregnant woman is most effective when administered 28 days or more before delivery, when a greater number of antibodies are transferred to the fetus. No adverse events were reported for the mother or the newborn with this measure, except for a small significant increase in chorioamnionitis seen by Kharbanda in 2014 [47–50]. The transplacental transfer of vaccineinduced antibodies from the pregnant woman to the fetus before birth and through maternal breastfeeding after birth is the basis of the prenatal immunization [19]. If the mother is vaccinated with the aP vaccine during pregnancy, her maternal antibodies against pertussis will

In 2012, vaccination of pregnant women in the third trimester of pregnancy was instituted by the American Centers for Disease Control and Prevention (CDC), regardless of their vaccination status, due to the loss of immunity a few months after booster vaccination. Several studies have attested the safety of dTap use in pregnant women [51, 52]. These studies showed that women vaccinated before pregnancy had less than 50% detectable antibodies against pertussis during gestation, which led to the adoption of the measure of vaccinating the woman at each gestation, regardless of her previous vaccination status [10, 53]. Vaccination in pregnant women between 27 and 36 weeks is more effective for the prevention of pertussis in young infants than vaccination in the second trimester of pregnancy. On the other hand, it is known that the vaccine given at the beginning of this period of 27–31 weeks is more effective in reducing pertussis in young infants. Efforts should be made for adequate vaccination schedule during prenatal consultations. Vaccination of 27–36 weeks is 85% more effective than Tdap

In the UK, vaccination was introduced in 2012 for pregnant woman between 28 and 32 weeks. In 2016, the country began recommending vaccination between 16 and 32 weeks, in order to improve the chance of vaccination to protect preterm infants, as well as to improve the level of maternal antibodies at birth. Later, vaccination during pregnancy protects the mother from developing the disease, giving some degree of protection to the newborn. Some studies have shown that women who were vaccinated after 32 weeks of pregnancy did not have the best level of passive protection for the newborn. In Belgium, the orientation for pregnant women

The timing of pregnant women vaccination is still controversial, with recent studies recommending it in the second trimester of pregnancy, while previous studies advocated for the

The recommendation of vaccination in pregnant women has expanded to several countries, such as Argentina, Belgium, Brazil, Colombia, El Salvador, Mexico, New Zealand, Australia,

It is known that the transfer of maternal antibodies to the newborn can interfere with the response of young infants to their own vaccination [56, 57], a phenomenon called blunting. This phenomenon depends on the type of vaccine antibody: the PT antibody increases after primary immunization, but the FHA antibody decreases in infants born from mothers vaccinated during pregnancy [19, 58, 59]. A study showed that the level of antibodies in the newborn

Switzerland, Ireland, the Czech Republic, Israel, Spain, and Greece [19].

also be transferred to the newborn through breast milk [46].

postpartum vaccination [12, 51].

34 Pertussis - Disease, Control and Challenges

third trimester [10, 52].

is from 24 to 32 weeks of gestation [19, 25, 54, 55].

The cocooning strategy consists of vaccinating the whole family and intimate contacts of the newborn, in addition to vaccination of the pregnant woman. It is important to remember that the vaccine takes 2 weeks to raise the antibodies to protective levels; therefore, the newborn is exposed to the transmission of the pertussis during this critical period [20]. Vaccination of household members is effectively provided as it is performed in a timely manner [16]. All caregivers of young infants (who feed, dress, and bathe them regularly) should also be considered for vaccination [46]. It is necessary to achieve adherence by all of those in contact with the newborn or young infant, in order to obtain the effectiveness of the cocooning strategy. It is important to note that the mother accepts this initiative better than the father of the child and other relatives tend to accept it even more rarely [20].

In an American study of 115 young infants with severe pertussis, 72% had previously had contact with adults or children over 11 years of age who showed acute cough for 5 days or more, referred to in the last month. This contact was often with the mother. The fact that infants received a dose of aP did not protect them from the disease [46]. The route of contamination was usually through a member of the family [6].

It has been observed that infants and young infants with older siblings are also at increased risk for pertussis. Each older sibling of the young infant increases the chance of having pertussis 1.5 times more, speaking in favor of the hypothesis that the source of contamination is the older sibling [12].

The American CDC recommends vaccination with a dose of Tdap for every adult and adolescent who have contact or who live with infants younger than 12 months of age [50]. Chile also adopted this strategy in 2011 with a significant impact: there was an 84% reduction in infant mortality when comparing cocooning strategy with no action taken [3].

Cocooning doses may reduce the serious morbidity of the infant, but timing is crucial, and the overall impact and cost-effectiveness may vary between countries and situations. The advantages of cocooning are better acceptance of vaccination in the postpartum period than during pregnancy, accessibility to the whole family, and the opportunity for health education. Disadvantages are the slow response to produce immunity to protect the newborn and logistical and economic issues. In addition, the challenges to implementing cocooning strategies include parental refusal, political hardship, logistical issues, and cultural issues. The cost–benefit ratio of cocooning is lower than maternal immunization, since it requires only one dose, whereas the cocooning strategy requires at least two doses for both parents [3, 61].

Determining the true incidence of pertussis in each country is vital in order for health authori-

Clinical Experiences in Pertussis in a Population with High Vaccination Rate

http://dx.doi.org/10.5772/intechopen.75684

37

Filumena Maria da Silva Gomes\*, Maria Helena Valente, Ana Maria de Ulhôa Escobar and

Department of Pediatrics, Faculdade de Medicina FMUSP, Universidade de São Paulo,

[1] Cherry JD, Heininger U. Pertussis and other *Bordetella*. In: Cherry JD, Demmler-Harrison GJ, Kaplan SL, Hotez P, Steinbach WJ, editors. Feigin & Cherry's Textbook of Pediatric Infectious Diseases. 7th ed. Philadelphia, PA: Elsevier-Sauders; 2014. pp. 1616-1639 [2] Nadel S. Infectious Diseases in the Pediatric Intensive Care Unit. London: Springer; 2008 [3] WHO 2014. WHO SAGE pertussis working group Background paper SAGE April 2014. Available: http://www.who.int/immunization/sage/meetings/2014/april/1\_Pertussis\_

[4] Provisional Pertussis Surveillance Report. CDC 2017. Morbidity and Mortality Weekly Report. 2017;**65**(52):1496. Available: https://www.cdc.gov/pertussis/downloads/per-

[5] Dalby T, Andersen PH, Hoffmann S. Epidemiology of pertussis in Denmark, 1995 to

[6] Nieves DJ, Heininger U. Bordetella pertussis. Microbiology Spectrum. 2016;**4**(3):EI10-

[7] Souder E, Long SS. Pertussis in the era of new strains of *Bordetella pertussis*. Infectious

[8] Pittet LF, Emonet S, François P, Bonetti E-J, Schrenzel J, Hug M, et al. Diagnosis of whooping cough in Switzerland: Differentiating Bordetella pertussis from Bordetella

[9] Centers for Disease Control and Prevention (CDC). Updated Recommendations for Use of Tetanus Toxoid, Reduced Diphtheria Toxoid and Acellular Pertussis Vaccine (Tdap) in Pregnant Women and Persons Who Have or Anticipate Having Close Contact with an Infant Aged <12 Months—Advisory Committee on Immunization Practices (ACIP) 2011.

ties to devise the best vaccine strategies to control the disease and its consequences.

**Author details**

São Paulo, SP, Brazil

0008-2015

**References**

Sandra Josefina Ferraz Ellero Grisi

\*Address all correspondence to: filumena.gomes@fm.usp.br

background\_FINAL4\_web.pdf [Accessed: 18 Oct 2017]

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Morbidity and Mortality Weekly Report. 2011;**60**(41):1424-1426

Vaccination of pregnant women is likely to be the most cost-effective additional strategy to prevent pertussis disease in young infants and appears to be more effective and favorable than the cocooning strategy.
