We appreciate the concern of the author on the affordability of Tdap for
adolescents and adults of all strata of society. The Indian Academy of
Pediatrics – Advisory Committee on Vaccines and Immunization Practices
(IAP-ACVIP) would urge the manufacturers to provide an affordable
vaccine to prevent pertussis in adolescents and adults. One Indian
manufacturer is likely to come up with a Tdap vaccine that may bring
down the cost. Moreover, when vaccines (or any other drugs) are used in
large quantities, their cost go down markedly. IAP-ACVIP thus recommends
Tdap vaccination in all adolescents , and would recommend it in
routine immunization program too.
Typhoid vaccine has emerged as an effective tool to
control typhoid fever especially in communities with high incidence of
disease. TCV is better than Typhoid Polysaccharide Vaccines (TPV) as it
can be administered in children aged between 6 months and 2 years, and
has longer duration of action . Repeated doses of TPV do not boost
immune response and natural infection does not always boost immune
response to TPV. TCV has been found to have efficacy not-inferior to
that of TPV in human exposure trial in adults where efficacy of TCV was
54.6% (95%CI 26.8-71.8) and that of TPV was 52.0% (95%CI 23.2-70.0) .
When TCV is recommended at 6 months of age there will
not be any need of TPV. However, those who have received the TPV earlier
can also be given TCV after a minimum of 4 weeks after TPV
administration. Although no such studies are available in this regard,
this interval is likely to avoid any interference with immune response
Benefits of vaccines should not be denied to any
individual for lack of resources and the need of the affordable vaccines
cannot be over emphasized in the current time. New recommendation on TCV
is not likely to reduce the coverage as only single dose is recommended
as of now whereas TPV needs to be given every 3 years. Moreover, TPV
cannot be used to provide protection in children up to 2 years of age.
Rather, the number of people receiving typhoid vaccine will become
higher as new recipients (children up to 2 years of age) will receive
TCV. Typhoid vaccination is also expected to serve as an important tool
to curb antimicrobial resistance. Large-scale, more aggressive typhoid
vaccination programs in children up to 15 years of age have the
potential to reduce the overuse of antimicrobials, thereby reducing
antimicrobial, resistance in many bacterial pathogens .
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Shivananda S, Guduru VK, et al. Indian Academy of Pediatrics
(IAP) Advisory Committee on Vaccines and Immunization Practices (ACVIP)
Recommended Immunization Schedule (2018-19) and Update on Immunization
for Children Aged 0 through 18 years. Indian Pediatr. 2018;55:1066-74.
2. Michel R, Garnotel E, Spiegel A, Morillon M,
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3. Jin C, Gibani MM, Moore M, Juel HB, Jones E,
Meiring J, et al. Efficacy and immunogenicity of a Vi-tetanus
toxoid conjugate vaccine in the prevention of typhoid fever using a
controlled human infection model of Salmonella Typhi: a randomised
controlled, phase 2b trial. Lancet. 2017;390(10111):2472-80.
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Gellin BG, et al. Typhoid conjugate vaccines: a new tool in the
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