Indian Academy of Pediatrics

Current Edition : Oct - Dec, 2001

"IAP BOOK ON IMMUNIZATION 2001"

Letter to the Editor

Sir,

We have gone through the "IAP BOOK ON IMMUNIZATION 2001" published by IAP. In this book under the heading of "IAP Immunization Time Table" (page 47) two different immunization options are given for Hepatitis B Vaccine. In the second option, IAP Immunization Committee recommends three doses of Hepatitis B Vaccie at six, ten and fourteen weeks respectively.

To our knowledge, there is no scientific data to recommend first dose of Hepatitis B Vaccine at six weeks. As we are all aware that for prevention of vertical transmission of Hepatitis B, it is absolutely essential to give first dose of Hepatitis B vaccine within twenty-four hours of birth. Also since, we really do not know the Hepatitis B carrier status in pregnant women all over India, it is prudent to recommend first dose at birth. Horizontal transmission of Hepatitis B is more commonly an adult disease. We as paediatricians have much greater role to play for prevention of vertical transmission and should be more concerned about it.

We only hope and pray that this recommendation has not come to accommodate a combination vaccine (Hep B vaccine + DPT vaccine) marketed by a pharmaceutical company. There is a foot note in this time table "to prevent perinatal transmission, birth dose of within 12 hours is essential." This is absurd. This is like telling that give polio vaccine at five years but if you want to prevent it earlier, give it at birth. This can be said for any vaccine. Please note that here we are not discussing anything about second and third dose of Hepatitis B Vaccine. Our objection is for IAP recommendation in the (second option) of 1st dose of Hepatitis B at 6 weeks.

By giving official option of giving first dose of Hepatitis B Vaccine at 6 weeks, IAP have given a free hand to pharmaceutical companies to promote combination vaccine to large number of unsuspecting general practitioners saying that "IAP has recommended first dose of Hepatitis B Vaccine at 6 weeks." We are not against combination vaccines but surely not this way. We know that there are many children who do not take Hepatitis B Vaccine at birth but this cannot go as official recommendation of IAP.

In fact IAP as an ambassador of child health, should have scuttled any attempt by pharmaceutical company to recommend first dose of Hepatitis B at 6 weeks. We believe, two options creates confusions. And why two options in case of Hepatitis B Vaccine only? Why can't the best option only be recommended?

By Dr. Bipin Shah, Dr. Bharat Parekh, Dr. Sanjay Pathak, Dr. Pravin Mehta

CLARIFICATION ON "IAP GUIDE BOOK ON IMMUNIZATION - 2001"

DR. A. PARTHASARATHY
CHAIRMAN, IAP COMMITTEE ON IMMUNIZATION

It is the global practice and known scientific procedure, to design a National Immunization Schedule based on the following:

Epidemiological relevance
Immunological appropriateness
Early Protection and Compliance
Economical Viability and
Socio Cultural Acceptibility.

The EPI schedule thus designed by the WHO has been adapted by different countries with reference to the above factors. India has adopted the EPI schedule in toto ever since 1978 and later in 1985 under UIP and has done extremely well with regard to high coverage and elimination of the targeted Vaccine Preventable diseases with appreciable success. Efforts are now on to introduce a few more antigens in the National Immunization Schedule due to the repeated recommendations of professional bodies like IAP, IMA, FOGSI, INASL etc like Hepatitis B, MMR, Typhoid and Hib in that order of priority.

World over the feasibility of using Combined Vaccines like DPT/HB, DPT/Hib or DPT/HB/Hib etc. has been recommended by the respective professional bodies, once such vaccines are licensed for use in a particular country. The 'IAP Policies, Guidelines and Recommendations 2001' was updated in April 2001. Prior to updation, the IAPCOI carefully examined all the existing recommendations of the Immunization Practices in the South East Asia Region, America, Canada, UK and the updated recommendations of the World Health Organization, finally decided to arrive at a consensus on 'IAP Immunization Time Table' and 'Immunization Time Tables in special Circumstances'. The whole idea of the IAP Immunization Guide Book 2001 was to present the consensus statements of IAPCOI 2001.

Since you have raised some queries on the contents of the Guide Book and preferred to call the currently, recommended IAP Hepatitis B Immunization Schedule as a "Controversial Schedule". I have preferred to offer the following explanations.

On scheduling immunization the Red Book 2000, updated in January 2001 observes: "The Immunization schedule used in the United States may not be appropriate for developing countries because of different risks, age specific immune responses, and vaccine availability. The schedule recommended by the Expanded Programme on Immunization of the World Health Organization should be consulted (http://www.who.org). Modifications may be made by the Ministries of Health in individual countries, based on local consideration".

I will now detail the various recommendations of the AAP and ACIP for HepatitisB Immunization in the US:

Hepatitis B Vaccine - Pre exposure Universal Immunization

"Routine Pre exposure Immunization is recommended for all infants at or soon after Birth (0 to 2 months), for all children 11 - 12 years of age and older persons in certain high risk groups".
"High seroconversion rates and protective concentrations of anti-HBs (>=10mIU/ml) are achieved when Hepatitis B Vaccine is administered in any of the various dose schedules, including those begun soon after Birth in term infants. Guidelines for minimum scheduling time between vaccine doses for infants are as follows:

Dose 1, at or soon after Birth
Dose 2, at least 1 month after dose 1
Dose 3, at least 2 months after dose 2

"The choice of schedule should be used to facilitate high rates of compliance with a 3 dose primary vaccine schedule".
The AAP schedule is flexible:

Dose 1: Birth to 2 months        Dose 1: Birth
Dose 2: 1 month to 4 months       (OR)        Dose 2: 2 months
Dose 3: 6 months to 18 months        Dose 3: 4 months

We in India (being in an Intermediate Zone of HBsAg carriers) cannot afford to be so flexible regarding HB vaccination. Hence, the IAP recommendation 2001 is as:

Dose 1 - Birth
Dose 2 - 6 weeks - More than 4 weeks interval before dose 1 and 2
Dose 3 - 14 weeks - 8 weeks interval between dose 2 and 3 and 3 ½ months
interval between dose 1 and 3
If HBIG is not available for babies born to HBsAg positive mothers a 4th dose of HB vaccine at 12 months of age
0,1 and 6 months schedule for older children, adolescents and adults. Immunogenicity-wise these schedules are well placed.

Most of the Indian trials with various brands of HB vaccination at 0,1 and 2 months schedule in all have recorded a protective value of more than 10mIU/L with high geometric titre (GMT) after 3rd dose. However, they suggest a booster at 5-6 years. Kindly refer to the product monographs of: (1) Shanvac / Hepashield,(2) Bevac, (3) Revac, (4) Hbvac etc.,
Unpublished data on studies carried out at CMC,Vellore, University College of Delhi and MAMC, Delhi have suggested high immunogenicity to HB vaccine at 6, 10 and 14 weeks schedule when combined DPT/HB vaccine formulation was given. In fact, 13 different schedules have been tried for HB vaccine at Global level.
WHO has recommended two different schedules in 1992:
For High Endemic areas - Birth, 6,10 and 14 weeks
For Low Endemic areas - 6, 10 and 14 weeks
The SAGE of CVI (Special Advisory Group of Experts of Children's Vaccine Initiative) had confirmed in 1996 high immunogenicity to HB vaccine when given at EPI schedule of 6, 10 and 14 weeks. Also, they recommend the use of combined vaccine formulation in countries where Universal HB vaccination is introduced to go ahead with the EPI schedule of 6, 10 and 14 weeks. SAGE felt that a booster may be needed 1 year later.
Hence, the IAP Time Table scheduling of HB vaccination at Birth, 6 and 14 weeks or at 6, 10 and 14 weeks (preferably with a combined vaccine formulation) is well thought out futuristic schedule for all developing countries where Universal HB immunization is contemplated. Whether a booster dose may be needed at 5-6 years with this schedule, will depend on the global recommendations for a booster of HB vaccine either with 0,1,2 or 0,1 and 6 months schedule.
Since AAP recommends the first dose of HB vaccine at 2 months (being in a low endemic HBsAg carrier state zone) the 2nd and 3rd dose are given at 2 months interval to fit in with their DPT+IPV schedule. Hence the recommendation 'the infant should least 6 months old for the 3rd dose'.
Though Universal HB Immunization is not practised in UK, the British Pediatric Association recommends the schedule of 0, 1 and 2 months for high risk group individuals and children travelling to intermediate and high endemic zones.

Hope you will appreciate that the IAP HB schedule which maintains a 6 weeks interval between dose I and II and an 8 weeks interval between dose II and III and an overall interval of 3½ months between the I and III dose is almost equivalent to the 8 weeks interval between subsequent HB vaccine doses even in the American Schedule viz. 2, 4, 6 months. The US Schedule does not speak of 5 months interval between dose II and III as mandatory.