Prevention of pertussis in infants has been a
matter of great concern owing to the heavy burden of fatality. Pertussis, also known as
whooping cough is a highly contagious bacterial disease characterised by
uncontrollable, violent coughing.
Compared with older
children and adults, infants aged less than 1 year of age have substantially
higher rates of pertussis and the largest burden of pertussis-related deaths.
Infants aged ≤ 2 months deserve special attention
since they are too young to be vaccinated. This vulnerable age group accounts
for the majority of pertussis cases, hospitalizations, and deaths. Vaccination against pertussis is provided
through the combination vaccine called DPT. DPT is protective against the
infectious diseases diphtheria and tetanus in addition to pertussis.
least eight variants of the DPT vaccines are available; variations are due to the
type of components used. Tdap, for example contains reduced concentrations of
diphtheria and pertussis antigens. The 'a' in 'ap' indicates that the acellular
pertussis toxoid has been used. These modifications are meant to reduce side
The Advisory Committee on Immunization Practices
the body that provides advice and guidance on effective control of vaccine-preventable diseases in the U.S.
civilian population, has updated its recommendations for
use of Tdap in unvaccinated pregnant women and persons who have or anticipate
having close contact with an infant aged <12 months.
Based on the available data from studies, ACIP
concludes that Tdap is safe in pregnant
women and causes no 'elevated frequency
or unusual patterns of adverse events'. A woman vaccinated with Tdap during
pregnancy is likely to be protected at time of delivery, and therefore less
likely to transmit pertussis to her infant.
receives protective antibodies against pertussis from its mother.
It has been found that
this form of protection is greater when the mother has received vaccination
during or before pregnancy. Infants born to unvaccinated mothers are at risk of
suffering from the infection.
A programme called cocooning
has been recommended by ACIP
since 2005. This is the strategy of vaccinating pregnant women immediately
after delivery and all other close contacts of infants aged <12 months with
Tdap to reduce the risk for transmission of pertussis to infants. Various
cocooning programmes succeeded in covering postpartum mothers (postpartum-after
). But they had limited success in vaccinating fathers or other
family members. ACIP however concludes that cocooning likely provides indirect
protection to infants and firmly supports vaccination with Tdap for
unvaccinated persons who anticipate close contact with an infant.
Both tetanus and
diphtheria toxoids (Td) and tetanus toxoid vaccines have been used extensively
in pregnant women worldwide to prevent tetanus in the new born. These vaccines
when administered during pregnancy do not damage the development of embryo,
i.e. they are not teratogenic.
Tdap may be administered after 20 weeks' gestation, says ACIP.
Vaccination of the mother during pregnancy is more cost effective and prevents
a greater proportion of infant
cases and deaths than postpartum maternal vaccination.
The updated guidelines published by the ACIP are
· Tdap vaccination
has been recommended for all pregnant women who previously have not received
Tdap. Tdap should be given during pregnancy, preferably during the third or
late second trimester (after 20 weeks' gestation). If not administered during
pregnancy, Tdap should be administered immediately after delivery (postpartum).
· Adolescents and adults (e.g.,
parents, siblings, grandparents, child-care providers, and health-care
personnel) who have or anticipate having close contact with an infant aged
<12 months should receive a single dose of Tdap to protect against pertussis
if they have not previously received Tdap. Tdap should be given at least 2
weeks before beginning close contact with the infant.
· If a tetanus and diphtheria
booster vaccination is indicated during pregnancy for a woman who has
previously not received Tdap (i.e., more than 10 years since previous Td), then
Tdap should be administered during pregnancy, preferably during the third or
late second trimester (after 20 weeks' gestation).
· A tetanus toxoid-containing
vaccine might be recommended for wound management in a pregnant woman if 5
years or more have elapsed since last receiving Td. If a tetanus booster is
indicated for a pregnant woman who previously has not received Tdap, Tdap
should be administered instead.
· Pregnant women who have never
been vaccinated against tetanus should receive three doses of vaccination
containing tetanus and reduced diphtheria toxoids at 0, 4 weeks, and 6 to 12 months.
Tdap should replace 1 dose of Td, preferably during the third or late second
trimester (after 20 weeks' gestation) of pregnancy.
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; Morbidity
& Mortality Weekly Report. 2011;60(41):1424-1426.Source