Recommendations for UseThere is no reason to believe that the disease burden of pertussis is low in adolescents in India. A safe and efficacious vaccine is available. The IAP COI therefore recommends offering Tdap vaccine instead of Td/TT vaccine in all children/ adolescents who can afford to use the vaccine (Category 2) in the schedule discussed below. It also recommends that studies aiming to determine the serosusceptibility to pertussis and prevalence of pertussis in children/adolescents/adults presenting with prolonged cough be conducted. In those children who have received all three primary and
the two booster doses of DTwP/DTaP, Tdap should be
administered as a single dose at the age of 10-12 years.
Catch up vaccination is recommended till the age of 18
years. A single dose of Tdap may also be used as replacement
for Td/TT booster in adults of any age if they have
not received Tdap in the past. A gap of 5 years should be
maintained between Tdap and previous TT/Td vaccine. A
gap of 2 years between Tdap and TT/Td is acceptable in
those children/adolescents
It is also acceptable to use Tdap as a replacement for TT/ Td in wound management of children aged 10 and above if they have not received Tdap in the past, and at least 5 years have elapsed since receipt of Td/TT vaccine. In children who have missed the 2nd booster of DTwP/ DTaP and who are 7 years of age or more, Tdap single dose is recommended at the time of presentation. In children who have not completed primary immunization with DTwP/DTaP and are more than 7 years of age, 1 dose of Tdap and 2 doses of Td at 0, 1 and 6 months are recommended. The single booster dose of Tdap may be followed by Td boosters every 10 years. There is no data at present to support repeat doses of Tdap (Austria is an exception where Tdap is recommended every 10 years). No tetanus prophylaxis is required for minor wounds if less than 10 years have elapsed since receipt of Tdap. No tetanus prophylaxis is required for major wounds if less than 5 years have elapsed since receipt of Tdap; if more than 5 years (but less than 10 years) have elapsed a single dose of TT may be given. In the absence of sufficient data on the efficacy, immunogenicity and duration of protection against pertussis with Tdap used as 2nd childhood booster, the IAPCOI does not recommend the use of Tdap vaccine as an alternative to DTaP/DTwP for the 2nd childhood booster in children below the age of 7 years at present. |
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Immunity against pertussis following primary/booster DTwP/ DTaP vaccination wanes over the next 6-12 years. Surveillance studies from the developed world chiefly US have shown a gradual increase in adolescent and adult pertussis cases over the past decade. This has been attributed to more awareness, better diagnosis and a real increase in pertussis cases due to loss of vaccine induced/natural immunity further reduced by lack of natural boosting. Adolescent/adult pertussis is responsible for considerable morbidity/loss of working days and is a reservoir for disease transmission to unvaccinated/ incompletely vaccinated neonates and young infants.
Hence several developed countries have instituted routine booster immunization of adolescents and adults with standard quantity tetanus toxoid and reduced quantity diphtheria and acellular pertussis vaccine (Tdap) instead of Td. The standard strength DTwP and DTaP vaccines cannot be used for vaccination of children 7 years and above due to increased reactogenicity.
Around 22,616 cases of pertussis were reported in India in 2006. This probably reflects a fraction of actual disease incidence as DTwP3 coverage in India is only 55% and coverage with the 1st and 2nd booster even lower with wide interstate variations. There is no data on incidence of adolescent and adult pertussis in India but is perceived to be significant especially in those states where childhood immunization coverage is good and reduced natural circulation of pertussis leads to infrequent adolescent boosting.
In India the currently available Tdap vaccine is Boostrix TM. It contains tetanus toxoid 5 Lf, diphtheria toxoid 2 Lf and the three acellular pertussis components namely, pertussis toxoid 8 ìg, filamentous hemagglutinin 8 ìg and pertactin 2.5 ìg. It contains aluminium hydroxide as adjuvant and no preservative. Another Tdap vaccine AdacelTM is likely to be licensed soon in India. The vaccine should be stored between 2 to 8°C, must not be frozen. The dose is 0.5 ml IM intramuscularly.
Immunogenicity studies have shown that antibody response to a single dose of Tdap booster in previously vaccinated children/adolescents is similar to that following 3 doses of full-strength DTwP or DTaP vaccines. Vaccine efficacy against clinical disease exceeds 90%.
Commonest side effect with Tdap
is pain at the local injection site in about 70% of vaccinees,
followed by redness and swelling. Systemic side effects like
fever, headache and fatigue are rarely seen. Serious adverse
events have not been reported. The contraindications are
serious allergic reaction to any component of the vaccine or
history of encephalopathy not attributable to an underlying
cause within 7 days of administration of a vaccine with
pertussis component.