The two articles on typhoid vaccination(1,2) published in the February
2009 issue of Indian Pediatrics raise some pertinent questions.
The author of the first article(1) does not consider
the burden of typhoid in India high enough to merit this being included in
the national immunization program or, for that matter, even important for
individual immunization. On the other hand, the very study that has been
quoted(3) not only makes out that India is a country with a high incidence
of typhoid disease but also makes a case for conjugate vaccine to enable
this to be given to children below 5 years.
The author has based his assessment of disease burden
entirely on culture positive cases. However, majority of cases in India
are diagnosed and treated without opting for blood culture and sensitivity
report which is not routinely available at all places. There are many
reports emanating from different parts that incidence of typhoid is even
going up even in children around two years of age(4,5). The author also
challenges the Cochrane review in this regard, which is considered to be a
robust evidence pertaining to any clinical entity, interventions and
therapy. They are not based on "assumption by extrapolation". The
conclusion reached by the author that typhoid is not a major public health
problem in India, therefore, needs clarification. It may not have high
mortality burden but definitely has high morbidity. Further, the author
states that the two dose typhoid vaccine was abandoned from the national
immunization schedule because of "lack of robust evidence". However, the
reasons for withdrawing this vaccine were the "reports of severe drug
reaction including the reports of septic shock like picture and sudden
deaths following these vaccines"(6).
In response to the second article(2), we have several
queries. Which evidence on vaccines should be considered as acceptable and
which one as non acceptable? What are the minimum standards laid down for
accepting studies on vaccines as authentic in terms of the place of study,
the authors, the number of cases undertaken in the study, the number and
type of publications, the manufacturers etc? What is the status of data
from our own country? Do we have ICMR data or any other data which we
would be willing to accept? On this count of lack of indigenous data, even
licensure of many new vaccines such as Rotavirus, JE SA-14-14-2 etc can
also be challenged.
What is the procedure of licensing a vaccine for use in
our country? Does not the national licensing/regulatory authority satisfy
itself on all accounts before granting permission for its use? What is the
liability/accountability of the regulatory authority if vaccines
supposedly not meeting the standards are licensed? What is the liability
of medical practitioners in case they decide to give or not to give the
vaccine on the basis of conflicting opinions? What is the liability of
academic forums from where these vaccines are launched to give them a
degree of credibility?
The IAP needs to address these questions and lay
down guidelines in respect to all vaccines as a matter of ethical
importance.
References
1. Mathew JL. Conjugate typhoid vaccine(s) in the
Indian context. Indian Pediatr 2009; 46: 182-184.
2. Shah NK. Indian conjugate Vi typhoid vaccine: Do we
have enough evidence? Indian Pediatr 2009; 46: 181-182.
3. Ochiai RL, Acosta CJ, Danovaro – Holiday MC, Baiqing
D, Bhattacharya SK, Agtini MD, et al. A study of typhoid fever in
five Asian countries: disease burden and implications for controls. Bull
WHO 2008; 86: 260 - 268.
4. Sinha A, Sazawal S, Kumar R, Sood S, Reddaiah VP,
Singh B, et al. Typhoid fever in children aged less than 5 years.
Lancet 1999; 354: 734-737.
5. Saha MR, Dutta P, Palit A, Dutta D, Bhattacharya MK,
Mitra U, et al. A note on incidence of typhoid fever in diverse age
groups in Kolkata, India. Japanese Journ Infect Dis 2003; 56: 121 – 122.
6. Shah NK. Typhoid vaccines revisited. In: Ganguly N,
Kundu R, Ghosh TK, editors. Common MDR infections in children. New Delhi:
CBS Publishers; 2005. p. 36-47.