RECONSIDERATION OF EARLY CHILDHOOD VACCINATION (AN EPIDEMIOLOGICAL STUDY ON RELATIONSHIPS BETWEEN VACCINATION AND AUTISM )

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1 RECONSIDERATION OF EARLY CHILDHOOD VACCINATION (AN EPIDEMIOLOGICAL STUDY ON RELATIONSHIPS BETWEEN VACCINATION AND AUTISM ) Fuad Amsyari* and Nur Mukarromah** ABSTRACT It has been an existing trend in health services management to vaccinate children at the earliest age possible in order to protect the children better from various serious diseases. Diphtheria, Pertusis, and Tetanus (DPT) vaccine for instance, has been recommended to be provided at less than three months old baby, as for BCG vaccine is even recommended at earlier age, i.e. at birth. However, whether such a health technology is in fact beneficial for the children is still hypothetical. On the other hand, the provision of multiple vaccines to early childhood might even be less effective since the immune system of the children is not yet well developed. Moreover, the response of smaller children in neutralizing toxic materials exposed to them might also still be weak. Provision of vaccines to children means not only providing the children with active materials of the vaccine, but also at the same time exposing the children to toxic substances available within the vaccine. Most vaccines in fact contain heavy metals mercury for preservative purposes and it has been well recognized that mercury is toxicant to human body. Therefore, possible health risk of giving multiple vaccines to early childhood should have more medical concern due two consideration, i.e. less developed immune system and higher risk of intoxication as the ratio of toxic material concentration exposure and the body weight of children is relatively greater. Findings of an epidemiological study conducted in Airlangga University in 2002, entitled Effect of Mercury containing Vaccine to the Prevalence of Autism", seem supporting such a concern. A case-control method has been used. A sample of 81 children under five who suffer from acquired autism has been compared to 81 children without autism. Variables related to autism such as age, pollution, delivery trauma, genetic endowment, and convulsion have been eliminated either by design or by statistical analysis. The result of the study clearly indicated that children with autism have been exposed higher level of mercury containing vaccines compared to those without autism. Odd Ratio was 9.69 with p=<.000. Dose-response relationship analysis also confirm the result. Logistic regression analysis indicated that more frequencies of getting mercury containing vaccine is related to higher risk of getting autism. The regression showed that risk of getting autism with 6 vaccination or more during early childhood will be.09 if other confounding variables are excluded. As the conclusion, it is suggested to reconsider seriously the use of mercury containing vaccines in early childhood as the risk of getting side effect of such soft technology in health care system is relatively clear. More scientific evidence is yet to be required to support vaccination in earlier childhood. Keywords: early childhood, vaccination, autism, epidemiology INTRODUCTION It has been an existing trend in health services management to vaccinate children at the earliest age possible in order to protect the children better from various serious diseases. Diphtheria, Pertusis, and Tetanus (DPT) vaccine for instance, has been recommended to be provided at less than three months old baby, while previously it was provided at least at three month age. BCG vaccine that was given previously at the age of one month or older is even recommended at earlier age, i.e. at birth. In addition, recently more various vaccines has been introduced to the children, such as hepatitis B, HiB, and MMR vaccines. *Department of Public Health and Preventive Medicine Airlangga University School of Medicine, Surabaya **Nursing Academy, Muhammadiyah University, Surabaya Vaccination in terms of how and when to be provided is certainly an important modern health technology. However, whether such a health technology, i.e. giving vaccination in earlier age, is in fact beneficial for the children is still hypothetical. On the other hand, the provision of multiple vaccines to early childhood might even be less effective since the immune system of the children is not yet well developed. Moreover, the response of smaller children in neutralizing toxic materials exposed to them might also still be weak. Provision of vaccines to children means not only providing the children with active materials of the vaccine, but also at the same time exposing the children to toxic substances available within the vaccine. Most vaccines, in fact, contain heavy metals mercury for preservative purposes and it has been well recognized that mercury is toxicant to human body. Therefore, possible health risk of giving multiple vaccines to early childhood should have more medical concern due two consideration, i.e. 1). less developed immune system; and 2). higher risk of intoxication as the ratio of toxic material concentration exposure and the body weight of Folia Medica Indonesiana 102

2 children is relatively greater. One of serious health problems related to the toxicity of heavy metals mercury that has been discussed recently is autism. The pathophysiology of autism is relatively welldeveloped, i.e. it is caused by brain development disorder or damage. The proses may start even from the early embryonic state. This may be happened due to infection during pregnancy by rubella, toxoplasm, cytomegalo virus, herpes simplex, and candida. In addition, it can also be caused by any traumatic brain haemorrhagic, food poisoning, and introduction of toxic chemical substances such as lead, mercury, cadmium and arsen during pregnancy. In postnatal period autism may be induced by infantile spasm, epilepsy, fenilketonuria, meningitis, encephalytis, and environmental induced toxicity, such as pollution, food, and possibly vaccination. Griggs (2001) mentioned that until this time many vaccines contain of thiomersal which contains of heavy metal of mercury. A baby aged 4 until 6 month with mercury in its body can not exclude this substance from the body, so the toxic material will be accumulated and cause various health problems. The mercury will affect the structure of cerebellum, amygdala, and hippocampus tissues. This part of the brain control movement, emotion, and memory coordination. Mercury also cause the change of body immunity and digestive system. Rusmil (2001) states that every dose of hepatitis B and DPT vaccine contains of 25 microgram of methylhg each. So a 6 month baby who gets a complete series of hepatitis B and DPT vaccines will get 3 times 25 microgram for hepatitis B vaccine and 3 times 25 microgram for DPT vaccine. So the total amount is 150 microgram methylhg, but it is still categorized below the tolerable dose defined by WHO. According to WHO, methylhg content is considered toxic if a baby receives Hg > 5 mg/weight/week. However such a dose of methylhg received by early aged babies has widely been questioned and recently related to the development of a pandemic phenomenon of autism. Does WHO recommendation for methylhg need to be reviewed (as happened to some other toxic materials)? Cave et al. in his book entitled What your doctor may not be telling you about children s vaccination stated the relationship between baby and autism cases, asthma, diabetes, and difficulty in learning. They tried to answer parents question about vaccination safety, immunization schedule and the way parents save their babies. It was mentioned that there is a direct line in increasing autism in children. The amount of vaccination which have to be recommended to baby have increased 3 times since As the realtionships between autism and vaccination is still in a controvercy, an epidemiological study has been conducted in Surabaya, from June to November Its objective is to study the correlation between vaccination and autism in relation to the policy of vaccination as a health technology. MATERIAL AND METHOD The design of the study was using a case-control method. Population that will be refered in the study were children aged 1 until 5 years old who have been diagnosed by neurologist in various medical clinics with an acquired autism. Eighty one autism cases as samples of the study are obtained from the total population of cases available in Surabaya using statistical formula as follows: n 1 = ((Z 2 1-α/2 + Z β ) 2.P.Q)/d 2 Another 81 children without autism from the same medical clinic were selected as control group and they were matched in age, sex, home location, and socioeconomic state of the family. Variables observed in this study were : 1. Independent variables : DPT, DT, MMR, Hepatitis B, HiB vaccines 2. Dependent variables : autism 3. Confounding variables : pregnancy history, birth trauma, breastfeeding history, previous medical history, genetic history, and home location related to pollution. Data are gathered by giving open and structured questionares to the mother of both autism and control children. Laboratorium analysis is used to get the primary data of mercury content in sample vaccines of MMR, DPT, Hepatitis B, HiB using Atomic Absorbtion Spectrophotometer (AAS) method. Data analysis is based upon comparation between cases and control group on various independent variables under observation using Chi Square test, Bartolomeus Test of Trend, and Logistic Regression. FINDINGS AND DISCUSSION 1. Mercury Content in Vaccine The followings are content of Hg in the vaccine used in the area of study. Folia Medica Indonesiana 103

3 Table 1. Mercury Content in Vaccine No Vaccine Observed HgContent HgContent In Label 1. DPT µg/5ml 500 µg/5ml 2. Morbilli < 1 µg/l 25 µg/0.5ml 3. Meningitis < 1 µg/l 25 µg/0.5ml 4. Hep-B Rekomb µg/0.5ml 25 µg/0.5ml 5. HB Vax II Rekomb µg/0.5ml <0.5 µg/0.5ml The table showed that there were Hg content in the samples of vaccine although the concentration was lower than what was stated in the label except for HB- Vax II Recombinant. The findings were only interpreted qualitatively and not tested statistically as sample size was minimal. 2. Relationship Between Autism and Exposure to Vaccine The followings is cross tabulation showing relationships between autism and frequency of vaccination in children: Table 2. Frequency Distribution of Respondents based on Exposure To Vaccination Exposure To Vaccination Observation Group (Frequency) Cases Control 6 X 22 (27.2%) 3 (3.7%) < 6 X (72.8% (96.3%) Total (100%) (100%) X P-Value Total 25 (15.3%) 137 (84.7%) 162 (100%) The table indicate that there is significant different between frequency of vaccination in children with autism (case) and non-autism (control). Chi-square result is x 2 = , p-value = Odd ratio is relatively big, i.e The frequency of vaccination is then classified into three categories, namely less than 5 times, 5 to 6 times, 7 times and more. Test of trend (Bartholomew s test) has been conducted and the result indicate a significant increasing trend, namely value of x 2 = , p-value = Table 3. Frequency Distribution of Respondents based on Exposure To Vaccination Exposure To Group Vaccination Cases Control Total 2 4 X 11 (13.6 %) 19 (23.5 %) 30 (18.5 %) 5 6 X 48 (59.3 %) 59 (72.8 %) 107 (66.0 %) 7 8 X 22 (27.2 %) 3 (3.7 %) 25 (15.4 %) Total 81 (100 %) 81 (100%) 162 (100 %) Folia Medica Indonesiana 104

4 The following graph indicates the relationship between autism and frequency to vaccination received by the children. Autism Proporsional 1 0,8 0,6 0,4 0,2 0 2 s/d 4 5 s/d 6 7 s/d 8 Exposure vaccine Figure 1. Relationship between frequency of vaccination and autism This result shows that more vaccine contains of mercury, the higher risk of autism will occur. 3. Modeling in Autism Incidence Some variables that usually are related to autism have also been evaluated in the study. As several variables have been excluded through research design such as age, sex, and socio-economic of families the other confounding variables are analyzed using statistical test. These variables were pregnancy and delivery history, breastfeeding, previous medical history of children, genetic aspect in terms of history of autism in family, and home location related to pollution in the area. The result of analysis is shown in the following table. Table 4 Chi-Square Analysis of Confounding Variables No. Confounding Variable X 2 P-Value 1. Pregnancy History Delivery History Breastfeeding Duration of Breastfeeding Previous Medical History Genetic History Home Location From aboved tables it was found that medical history, genetic aspect, and home location related to pollution was found significantly different between cases and control group. Therefore further statustical analysis was done to know the effect of vaccination on autism using logistic regression involving those 3 variables. The following table is the results of logistic regression analysis. From 4 variables involved in the multivariate analysis the three varibles were found significant in relation to autism, namely frequency of vaccination which were categorized into frequency 1 and 2, previous medical history of the children, and home location related to pollution. As for genetic history was excluded to the model as it was found statistically not significant. Folia Medica Indonesiana 105

5 Table 5 The Result of Multiple Logistic Regression Analysis of Autism Variable B Wald P-Wald Exp B Exposured Vaccine Frequency Exposured Vaccine Frequency Previous Medical History Home Location Constant From the logistic regression analysis it can be developed a quantitative model of factors determining the incidence of autism. The following is the mathematical P(X) = 1 + e model of incidence of autism. A multiple regression logistic analysis model : 1 ( frek frek rpt lrb) From the model it can be calculated the risk of getting autism if those 3 status of variables is known. It was found that autism risk after children received 5-6 vaccination containing methylhg during infancies with good medical history and living in unpolluted location is 9%. CONCLUSION The result of the study clearly indicated that children with autism have been exposed higher level of mercury containing vaccines compared to those without autism. Odd Ratio was 9.69 with p=<.000. Dose-response relationship analysis also confirm the result. Logistic regression analysis indicated that more frequencies of getting mercury containing vaccine is related to higher risk of getting autism. The regression showed that risk of getting autism after 5-6 vaccination containing methylhg during early childhood will be.09 if other confounding variables are controlled. RECOMMENDATION It is suggested to reconsider seriously the use of mercury containing vaccines in early childhood as the risk of getting side effect of such soft technology in health care system is relatively clear. More scientific evidence is yet to be required to support vaccination in earlier childhood. REFERENCES Dagg P, 2001, Pervasive Developmental Disorder : Autism in Schmetzer AD et al (Eds) htm (29/10/2002) Fleiss J, 1972, Statistical Methods for Rates and Proportions, a Willey Interscience Publication Frith, Uta, 1994, Autism Explaining the Enigma, BlackWell, Oxford UK & Cambridge USA Frank C. Lu, 1995, Toksikologi Dasar, Penerbit Universitas Indonesia Grigg, Ted; 2001, Silent Epidemic : Autism, Artickel, The Advocate Holmes. A, 2000, Autism Treatments, holmes.htm Shaw. W, 2002, Biological Treatments for Autism and PDD, The Great Plains Laboratory, Inc Schaffer,Lenny ; 2001, Harvard Clinic Scientist finds, gutautism link, like Wakefield findings, FEAT Newsletter Tsai LY, 2002, What you should know in medication treatment of Autism Spectrum Disorders In: Autism Society of America National Conference on Autism, Atlanta, Georgia, 2-5 July 2002 Folia Medica Indonesiana 106