December 1998, Volume 48, Issue 12

Original Article

Efficacy of Low Dose Intra-Dermal Hepatitis B Vaccination Schedule

Bader Faiyaz Zuberi  ( Department of Medicine, Chandka Medical College, Larkana. )
Muhammad Ramzan Rajput  ( Department of Medicine, Chandka Medical College, Larkana. )
Lala Muzaffar  ( Department of Medicine, Chandka Medical College, Larkana. )
Noorunisa Jatoi  ( Department of Medicine, Chandka Medical College, Larkana. )
Wazir Muhammad Shaikh  ( Department of Medicine, Chandka Medical College, Larkana. )

Abstract

Efficacy of low-dose, intra-dermal hepatitis B vaccination was assessed among sixty-one doctors and paramedical staff of Chandka Medical College Hospital, Larkana. Subjects were randomly divided into two groups. Group-A (n=25) received 20 ug of purified Hepatitis B Surface Antigen (Euvax B, LG Chemicals) by i.m. injection in the deltoid by 0,1 and 6 schedule while group B (n=36) received 5 U8 intra-dermally by same schedule. The mean value of HBsAb titers checked 4 weeks after the last dose in group A were 158.6±51.8 mlU/ml and that in Group B were 68.2±26.6 mlU/ml (p<0.0001; 95% C.!. 69.2 and 111.5). Number of subjects attaining the protective titers of 10 mlU/ml in group A was 95.7% and that in group B was 90.9% (p=O.5). We conclude that 5 ug intradermal hepatitis B vaccination is effective (JPMA 48:377,1998).

Introduction

Massive increase is reported in cases of Hepatitis B all over the world in the last decade. The programs of targeted immunization of high-risk groups have failed to check the inereasing rate of infection. In USA alone, 300,000 new cases of hepatitis B infection occur each year leading to 350-450 fulminant deaths, 27000-42000 chmnic carriers and ultimately 4000-5500 deaths per year from cirrhosis and primary liver cancer1. In Pakistan the hepatitis B carrier state has been reported to be 10.7~11.3%2,3. The World Health Organization (WHO) recommends that hepatitis B vaccine should be incorporated into national universal vaccination programs by 1997. The Viral Hepatitis Prevention Board (VHPB) supported the recommendation of the World Health Organization (WHO) that hepatitis B vaccine should be incorporated into national universal vaccination programs by 19974,5. The cost of vaccination is an important issue in a developing country like Pakistan, as majority of the population at risk is not inapositionto afford it. Recently some workers have reported the successful protection achieved by low dose vaccination6. Keeping in view the WHO recommendations of universal vaccination and poverty of our country we decided to check the response to the low dose vaccination against hepatitis B in our setting.

Subjects and Methods

Doctors and paramedical staff of Chandka Medical College, Larkana, without previous history of jaundice who were negative to HBsAg were inducted after informed consent. Complete blood counts and liver chemistries were done in all the selected subjects. Subjects were divided into two groups with the help of random tables. Group-A received 20 ug of purified Hepatitis B Surface Antigen (Euvax B, LG Chemicals) by i.m. injection in deltoid at 0,1 and 6 month schedule and group-B received 5 p.g of same vaccine same schedule butby intra-dermal injection in forearm. HBsAb was done 4 weeks after the third dose to assess the efficacy of vaccination. Titers of 10 mlU/ml or more were considered protective7’8. HBsAg and HBsAb were done utilizing standard ELISA kit, Complete blood counts were done on Sysmex K-4500 automated cell counter while liver chemistries were done on BM Photometer 5010 using Boehringer Mannheini reagents.
Statistical analysis
All results for continuous variables are expressed as means±SD. The Mann-Whitney U test and t-test were used to compare continuous variables between different groups. The p values for comparisons of categorical variables were generated by the chi- square test for proportions and values of less than 0.05 were considered statistically significant. The values of HBsAb were re-coded into a different variable with values <10 mlU/ml re- coded as ‘0’ and values of>10 mlU/ml re-codedas ‘1’ for non-parametnc analysisby Mann-Whitney U test. All calculations were done with SPSS 7.0 (SPSS, Chicago).

Results

Sixty-one subjects were selected fulfilling the criteria described earlier and were allotted randomly into two groups.
Twenty-five were allotted to group-A and thirty-six to group B. Mean age of subjects in group-A was 28±3.1 years and that in group-B was 30±2.8 years. Two subjects from group-A and three from group-B did not report forHBsAb testing and were excluded. The mean value of HBsAb titers in Group-A was 158.6±5 1.8 mlU/ml and that in group-B was 68.2±26.6 mlU/ml. The difference in the antibody titers was statistically significant (p<0.0001; 95% C.I. 69.2 and 111.5). Number of subjects attaining the protective titers of_10 mlU/ml in group A was 22/23(95.7%) and that in group-B was 30/33(90.9%). Using Mann-Whitney U test to see significance of difference between the subjects of two groups attaining the protective antibody titers, the mean and sum of ranks in group-A was 29.28 and 673.5 respectively and that in group-B was 27.95 and 922.5 respectively. The 2-tail significance was found 0.5 showing that the difference in number of subjects attaining protective titers of antibodies in two groups was not significant.

Discussion

Hepatitis B is emerging as amajorhealthprobleminour country. About 30% of acute viral hepatitis inPakistan are due to hepatitis B9. The consequences of the infection could be fatal and require lot of national resources and individual expenses on the management of its sequelae without much favourable results. It has been shown that the hepatitis B vaccination is extremely cost effective in terms of the cost incurred on the management, hospitalization and work loss10-12. The present study shows that the low dose of 5 ug is effective in mounting the immune protective response in 90.9% aM in reducing the cost of immunization by 75%. Different centres are experimenting with different ages and schedule13-15. Adequate immune responses are reported with doses as small as 2 ug15,16. Inthis study, the mean HBsAb titers were higher in group A (158.6 mlU/ml) than those in group B (68.2 mlU/ml), but still they were much higher than the 10 mlU/ml which is taken as level of protection7,8. The protective levels were attained in 90.9% of subjects in low dose group showing good efficacy of this schedule. The non-responders to primary immunization are benefited by an extra dose of vaccine17. Due to the presence of anamnestic response, the booster dose of hepatitis B vaccine is- currently not recommended18.

References

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