Avaliação da resposta imunologica a vacina contra a hepatite B aplicada pelas vias intradermica ou intramuscular em profissionais da saude de hospital universitario : seguimento de cinco anos

AUTOR(ES)
DATA DE PUBLICAÇÃO

1996

RESUMO

Health care workers (HCW) present HBV risk of infection three to five times higher than the population in general. However, high vaccine cost is an obstacle to assure fulI vaccinal coverage. Several studies have been made in order to try to make the vaccinal scheme more economical but effective. Intradermic HBV vaccine reduces seven to ten times the cost of vaccination and in certain population groups its effectiveness is similar to intramuscular application. In order to find altemate and more economic schemes for vaccination against HBV in HCW, we have selected a group of health care workers at Unicamp to receive the HBV vaccine. These workers have been divided into two groups, according to the application route: intradermic (ID) or intramuscular (1M). All the workers who received ID application and part of those who received the vaccine via 1M were followed up for evaluation of the immunologic response to the vaccine through both quantitative and qualitative anti-HBs investigation. The proposed vaccination scheme was of three doses, at O, 1 and 6 months intervals. The vaccine used was the Belgium recombinant vaccine (Engerix B, SmithKline), with 20 ? g (1 ml) dose for 1M application and 0.2 ? g (0.1 ml) dose for ID application (ventral side of the left forearm). AlI the workers receiving the first vaccine dose were submitted to a blood test to determine the prevalence of anti-HBc as a marker of the previous HBV infection. New blood samples were collected at the time the 2nd and 3rd doses were applied and 6 months after the last one for anti-HBs survey. The workers who completed the program and who were stilI with the university, were called after 5 years for a new title of anti-HBs and survey on anti-HBc. At that time, the subjects who had anti-HBs titles <10 mUI/ml after having shown seroconversion with the first scheme were administered a booster dose of the vaccine (20 ? g), via 1M. After two to four weeks a new anti-HBs title was made. Of the 1,117 subjects receiving the first dose, 463 (41.5%) received the vaccine via ID and from the remaining 654 (58.5%) receiving the vaccine via 1M, 228 were further divided into a seroconversion follow-up subgroup. The prevalence ofthe Anti-HBs among the 1,117 HCW was of 10.3%. Certain professional categories or specialties have shown higher prevalences, such as laboratorians (14.4%), surgeons (16.2%) and orthopedists (16.7%). There were no anti-HBc reagent cases among anesthetists, anatomopathologists and radiologists. We have also noted higher prevalence of anti-HBc on subjects over 35 years old and on those who have been working in the health care area for more than 10 years. Among the 115 anti-HBc reagent HCW, 2 have shown to be HBsAg reagent and the remaining were positive for anti-HBs, indicating a prevalence ofHBV ofO.2%. Attendance between the first and the second doses was of 81.8% and between the second and third 79.4%. ln the intradermic group, however, absenteism was of 29.3%. VBH vaccination was safe and well tolerated, with no adverse reactions in 77.4% of the subjects. Reactions were more frequent in the ID group than in the 1M group (31.4%, 15.7%; p=0,000). ln the ID group, local reactions prevailed (hyperemia, pruritus and edema) and in the 1M group, systemic reactions (drowsiness, myalgia, nausea). There was one case of anaphylactic reaction after intradermic application of the second dose of the vaccine. After three doses of the vaccine, the seroconversion for anti-HBs was of 92.2% in the 1M group and 59.9% in the ID group. lu the 1M group, we have achieved anti-HBs <10 mUI/ml titles in 24.5%, titles between 10 and 100 mUI/ml in 13.7% and titles above 100 mUI/ml in 61.8%. ln the ID group, these titles were found in 46.4%; 34.3% and 19.3%, respectively. Age below 30 years and being female were the factors associated with an adequate vaccinal response. Five years after the vaccinal scheme, we found titles of anti-HBs >= 10 mUI/ml in 73.7% and 43.2% ofsubjects from groups 1M and ID, respectively. After administering a booster dose in 36 subjects with anti-HBs <10 mUI/ml, 88.9% have shown titles of anti-HBs protectors; 83.3% have shown titles above 150 mUI/m1

ASSUNTO(S)

imunização hepatite b hepatite - vacina

ACESSO AO ARTIGO

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