Reactogenicity and immunogenicity of three different lots of a hepatitis A vaccine L. Theilmann *l, B. Kallinowski*, K. Gmelin t, F. Hofmann;, N. Scheiermann~, B. Wohland ~, H. Stickl II, H. Maiwald, F. K. Moriabadi', H. L. Bock +, R. Clemens+, A. Safary ° and F. E. Andr~ ° To study the immunogeniciO' and reactogeniciO, (~['an inactivated hepatitis A vaccine, 204 health), individuals were randomized into three equal groups, each to receive a d(fferent vaccine lot. Each subject received a total of three dose, each (~[ 720 E L I S A units o / hepatitis' A vaccine HM175, according to a 0 and 1 month primart' vaccination schedule, with a booster dose given at month 6. Side effects were low and were < 30% after the second injection. All subjects but one had antibodies to hepatitis" A virus two months q[ter the first dose o f vaccine.At month 6 all vaccinees had seroconverted. There were no d(fferences between the three vaccine lots with respect to side effects, seroconversion rates and geometric mean titre oJ antibodies. We conclude that the three lots 0[ inactivated hepatitis A vaccine are safe, well tolerated and equally immunogenic.
Keywords: Activehepatitis A vaccination: immunogenicity: safety
INTRODUCTION Hepatitis A virus (HAV) is the causative agent for most cases of travellers' hepatitis, an infectious disease which is usually acquired during travels to areas where hepatitis A virus infection is endemic ~. In the Federal Republic of Germany, up to 50% of all reported cases of viral hepatitis are due to HAV infection. Although infection with HAV usually is limited and does not develop into chronicity, 20% of all patients experience hepatitis for several months 2. In contrast to Western Europe and the USA, where a decrease of HAV infection has been observed in the last two decades due to an increase in hygienic standards, HAV infection is common in Africa, Asia and South America, as determined by the presence of anti-HAV antibodies in serum 3. In Germany, < 20% of people aged 20 30 years are positive for anti-HAV 4, and thus run a high risk of getting infected with HAV when travelling to endemic areas. At present, specific prophylaxis against HAV infection is obtained by the administration of immunoglobulins. *Medizinische Universit&tsklink, Heidelberg, Germany. tLuitpoldkliniken, Bad Kissingen, Germany. :Universit&tsklinik, Freiburg, Germany. §St. Markus Krankenhaus, Frankfurt, Germany. y- Kreiskrankenhaus, Reutlingen, Germany. Institut for Toxikologie und Umwelthygiene, M0nchen, Germany. 'St~.dtisches Krankenaus, Passau, Germany. +SmithKline Beecham, Munich, Germany. 0SmithKline Beecham Biologicals, Rixensart, Belgium. 1To whom correspondence should be addressed
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Vaccine, Vol. 10, Suppl. 1, 1992
Although the rate of infection is decreased significantly by this procedure, its protective effect only lasts for 3-4 months due to the short half-life of the passively acquired immunoglobulins. Recently, a newly developed HAV vaccine became available for active immunization ~. In this study, we tested the reactogenicity and immunogenicity of three consecutive vaccine lots in order to evaluate the use of this vaccine for the prophylaxis of HAV infection. MATERIALS
AND METHODS
Vaccine The vaccine used was the inactivated HAV vaccine strain H M I 7 5 (SmithKline Beecham Biologicals)containing 720 ELISA units (El.U), adsorbed on to aluminium hydroxide in a total volume of 1 mP. Three consecutive lots of vaccine were studied.
Study design Alter approval of the study by the ethical review committee of the Heidelberg University, healthy volunteers 20-40 years of age were recruited in five German centres. In all cases informed consent and a medical history were obtained and a physical examination performed. Volunteers meeting one or more of the following criteria were excluded: chronic liver disease, chronic hepatitis B virus infection, diabetes mellitus, malignant diseases, alcoholism, elevated liver enzymes, regular intake of drugs except oral contraceptives, pregnancy, intention to travel 0264-410X/92/100S132-03 ,~ 1992 Butterworth-Heinemann Ltd
Reactogenicity and immunogenicity of hepatitis A vaccine: L. Theilmann
et al.
during the study to areas known to be endemic for HAV, positive test for anti-HAV antibodies. Volunteers accepted for the study were randomized into three groups, each receiving vaccine from one of three lots. The vaccine was administered into the deltoid muscle at months 0, 1 and 6. y-Glutamyltransferase, alanine aminotransferase, aspartate aminotransferase (AST) and antibodies to HAV were tested prior to the study and at months 1, 2, 6 and 7. Quantitative determination of anti-HAV antibodies was performed by SmithKline Beecham Biologicals (Rixensart, Belgium), using a sensitive ELISA 6. Side effects were recorded after each vaccination using a questionnaire, which had to be filled out by the vaccinee for the first three days after each vaccination. Statistical analysis was performed using Z-~ analysis and Fisher's exact test.
Table 1 Seroconversion rate and geometric mean titre of anti-HAY antibodies using three consecutive lots of vaccine
RESULTS
Pre: before vaccination; M1, M2, M6, M7: months; 1, 2, 6 or 7, respectively, after the first vaccination. A second immunization was given at month 2 and a booster injection at month 6. There were no significant differences between the three groups with respect to seroconversion or height of antibody titres
A total of 213 volunteers were included in the study and 204 persons completed the study. Four subjects were excluded because they were older than 40 years, one had elevated serum liver enzymes before the study, one woman was pregnant, one person had received immunoglobulins, one was positive for anti-HAV antibodies and one person refused further participation after the first injection for undisclosed reasons. The average age of the participants was 27.2 years and all three groups were comparable in respect to age and sex ratio. During the study, two participants showed a transient elevation of AST up to 45 IU/1, which were not considered to be related to the vaccination. Side effects were divided into local (soreness, swelling, induration) and systemic (fever, nausea, headache). Incidence of overall side effects was 49.7% after the first injection and decreased after the second and third injection to < 30% (Figure 1). Pain at the site of injection was most commonly reported with symptoms disappearing usually after one day. The highest rate of systemic side effects reported, mainly headache, was 6.6%. Only two vaccinees complained of symptoms lasting longer than 2 days. These disappeared at the end of the third day. The vaccine proved to be highly immunogenic. One month after the first injection, > 90% of all vaccinees 100 oo
90
~
8o
~
70
.~
6o
"~
50
.E
40
o
x: m
30
~
2o
¢-
"~ ~
10
o
First
Second
Third
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Figure 1 Incidence of side effects, reported after the first three days after each vaccination. I , Local; [], Systemic
Seroconversion Lot
Time
n
n
1
Pre M1 M2 M6 M7 Pre M1 M2 M6 M7 Pre M1 M2 M6 M7
67 67 66 66 64 62 62 62 59 56 68 68 67 65 65
0 62 66 66 64 0 57 61 59 56 0 65 67 65 65
2
3
%
GMT (mlU/ml)
92.5 100.0 100.0 100.0
244 532 410 4257
91.9 98.4 100.0 100.0
304 498 368 4097
95.6 100.0 100.0 100.0
281 577 427 4387
had developed anti-HAV antibodies and one month after the second injection all but one vaccinee had seroconverted (Table 1). The latter subject had seroconverted by month 6. After month 2, one month after the second injection, the titre of antibodies decreased only slightly until month 6. The booster injection given at that time resulted in a more than tenfold increase in antibody titre. There was no difference with respect to side effects or immunogenicity of the three lots of vaccine.
DISCUSSION The prevalence of anti-HAV antibodies in sera from Western European individuals has decreased significantly in recent years 7. More than 90% of individuals younger than 30 years lack protective antibodies. As this age group comprises the most active travellers to areas in which HAV infection is endemic, long-term and reliable protection appears to be necessary. Active immunization would be the most suitable protection against HAV infection for such individuals. Our study shows that the newly developed HAV vaccine is a good candidate for this purpose. As early as one month after the second injection, all but one vaccinee had protective anti-HAV antibodies. This person had, however, developed antibodies by month 6. Thus, all vaccinees responded to the vaccine, irrespective of the lot used, and all lots studied appeared to be comparable with respect to immunogenicity and reactogenicity. Side effects were minor in all three groups, although a rate of 30% appears at first sight to be high. It has to be stressed, however, that all participants were asked thoroughly for all possible side effects, thus probably leading to an overestimation. Discomfort and pain at the site of injection were the most frequent complaints. The observed rate, however, appears to be comparable to rates recorded in studies using other similar vaccines, as for example hepatitis B vaccines 8. Two individuals showed a transient rise in serum transaminases. This cannot be attributed to the vaccine, as such events are
Vaccine, Vol. 10, Suppl. 1, 1992
$133
R e a c t o g e n i c i t y a n d i m m u n o g e n i c i t y o f hepatitis A vaccine: L. T h e i l m a n n et al.
observed with a similar frequency in the general population ~. In summary, the three consecutive lots of the HAV vaccine tested, were all equally highly immunogenic and vaccination was accompanied by only minor side effects. We therefore conclude that the vaccine is safe, well tolerated and suitable for the prophylaxis of HAV infection.
REFERENCES Steffen, R. Reisemedizin. Springer, Heidelberg, 1984, pp. 90-96 Lemon, S. Type A viral hepatitis. N EngL J. Med. 1985, 313, 1059-1067 Szmuness, W., Dienstag, J., Purcell, R.H., Stevens, C., Wong, D.C., Ikram, H., Bar-Shangs, S., Beasley, R.P., Desmyter, J. and Gaon, J.A. The prevalence of antibody to hepatitis A antigen in various of the world: a pilot study. Am. J. EpidemioL 1977, 106, 392~.398
S134
Vaccine, Vol. 10, Suppl. 1, 1992
Fr6sner, G.G. Epidemiology of hepatitis A. Viral Hepatitis (Ed Deinhardt, F.) Marcel Dekker, New York, 1983, pp. 201-212 5 Andre, F., Hepburn, A. and D'Hondt, E. Inactivated candidate vaccines for hepatitis A. Prog. Med. ViroL 1990, 37, 72-95 6 Delem, A., Denamur, F. and D'Hondt, E. Serum antibodies response to HAV-killed vaccine: correlation between three methods of titration. International Symposium on Viral Hepatitis and Liver Disease, Houston, USA, 4-8 Apr 1990 (abstract) 7 Fr6sner, G.G., Papaevangelou, G., Butler,R, Iwarson, S., Linholm, A., Courource-Pauty, A., Haas, H. and Deinhardt, F. Antibody against hepatitis A in seven European countries. Am. J. EpidemioL 1979, 110, 63q38 8 Andre, F. Overview of a 5--year clinical experience with yeast derived hepatitis B vaccines. Vaccine 1990, 8 (Suppl.), 74.-78 9 Sherman, K.E., Dodd, R.Y. and the American Red Cross Aminotransferase Study Group. Alanine aminotransferase levels among volunteer blood donors: geographic variation and risk factors: J. Infect. Dis. 1982, 145, 383-386 4
Keywords: Activehepatitis A vaccination: immunogenicity: safety
INTRODUCTION Hepatitis A virus (HAV) is the causative agent for most cases of travellers' hepatitis, an infectious disease which is usually acquired during travels to areas where hepatitis A virus infection is endemic ~. In the Federal Republic of Germany, up to 50% of all reported cases of viral hepatitis are due to HAV infection. Although infection with HAV usually is limited and does not develop into chronicity, 20% of all patients experience hepatitis for several months 2. In contrast to Western Europe and the USA, where a decrease of HAV infection has been observed in the last two decades due to an increase in hygienic standards, HAV infection is common in Africa, Asia and South America, as determined by the presence of anti-HAV antibodies in serum 3. In Germany, < 20% of people aged 20 30 years are positive for anti-HAV 4, and thus run a high risk of getting infected with HAV when travelling to endemic areas. At present, specific prophylaxis against HAV infection is obtained by the administration of immunoglobulins. *Medizinische Universit&tsklink, Heidelberg, Germany. tLuitpoldkliniken, Bad Kissingen, Germany. :Universit&tsklinik, Freiburg, Germany. §St. Markus Krankenhaus, Frankfurt, Germany. y- Kreiskrankenhaus, Reutlingen, Germany. Institut for Toxikologie und Umwelthygiene, M0nchen, Germany. 'St~.dtisches Krankenaus, Passau, Germany. +SmithKline Beecham, Munich, Germany. 0SmithKline Beecham Biologicals, Rixensart, Belgium. 1To whom correspondence should be addressed
$132
Vaccine, Vol. 10, Suppl. 1, 1992
Although the rate of infection is decreased significantly by this procedure, its protective effect only lasts for 3-4 months due to the short half-life of the passively acquired immunoglobulins. Recently, a newly developed HAV vaccine became available for active immunization ~. In this study, we tested the reactogenicity and immunogenicity of three consecutive vaccine lots in order to evaluate the use of this vaccine for the prophylaxis of HAV infection. MATERIALS
AND METHODS
Vaccine The vaccine used was the inactivated HAV vaccine strain H M I 7 5 (SmithKline Beecham Biologicals)containing 720 ELISA units (El.U), adsorbed on to aluminium hydroxide in a total volume of 1 mP. Three consecutive lots of vaccine were studied.
Study design Alter approval of the study by the ethical review committee of the Heidelberg University, healthy volunteers 20-40 years of age were recruited in five German centres. In all cases informed consent and a medical history were obtained and a physical examination performed. Volunteers meeting one or more of the following criteria were excluded: chronic liver disease, chronic hepatitis B virus infection, diabetes mellitus, malignant diseases, alcoholism, elevated liver enzymes, regular intake of drugs except oral contraceptives, pregnancy, intention to travel 0264-410X/92/100S132-03 ,~ 1992 Butterworth-Heinemann Ltd
Reactogenicity and immunogenicity of hepatitis A vaccine: L. Theilmann
et al.
during the study to areas known to be endemic for HAV, positive test for anti-HAV antibodies. Volunteers accepted for the study were randomized into three groups, each receiving vaccine from one of three lots. The vaccine was administered into the deltoid muscle at months 0, 1 and 6. y-Glutamyltransferase, alanine aminotransferase, aspartate aminotransferase (AST) and antibodies to HAV were tested prior to the study and at months 1, 2, 6 and 7. Quantitative determination of anti-HAV antibodies was performed by SmithKline Beecham Biologicals (Rixensart, Belgium), using a sensitive ELISA 6. Side effects were recorded after each vaccination using a questionnaire, which had to be filled out by the vaccinee for the first three days after each vaccination. Statistical analysis was performed using Z-~ analysis and Fisher's exact test.
Table 1 Seroconversion rate and geometric mean titre of anti-HAY antibodies using three consecutive lots of vaccine
RESULTS
Pre: before vaccination; M1, M2, M6, M7: months; 1, 2, 6 or 7, respectively, after the first vaccination. A second immunization was given at month 2 and a booster injection at month 6. There were no significant differences between the three groups with respect to seroconversion or height of antibody titres
A total of 213 volunteers were included in the study and 204 persons completed the study. Four subjects were excluded because they were older than 40 years, one had elevated serum liver enzymes before the study, one woman was pregnant, one person had received immunoglobulins, one was positive for anti-HAV antibodies and one person refused further participation after the first injection for undisclosed reasons. The average age of the participants was 27.2 years and all three groups were comparable in respect to age and sex ratio. During the study, two participants showed a transient elevation of AST up to 45 IU/1, which were not considered to be related to the vaccination. Side effects were divided into local (soreness, swelling, induration) and systemic (fever, nausea, headache). Incidence of overall side effects was 49.7% after the first injection and decreased after the second and third injection to < 30% (Figure 1). Pain at the site of injection was most commonly reported with symptoms disappearing usually after one day. The highest rate of systemic side effects reported, mainly headache, was 6.6%. Only two vaccinees complained of symptoms lasting longer than 2 days. These disappeared at the end of the third day. The vaccine proved to be highly immunogenic. One month after the first injection, > 90% of all vaccinees 100 oo
90
~
8o
~
70
.~
6o
"~
50
.E
40
o
x: m
30
~
2o
¢-
"~ ~
10
o
First
Second
Third
Vaccination
Figure 1 Incidence of side effects, reported after the first three days after each vaccination. I , Local; [], Systemic
Seroconversion Lot
Time
n
n
1
Pre M1 M2 M6 M7 Pre M1 M2 M6 M7 Pre M1 M2 M6 M7
67 67 66 66 64 62 62 62 59 56 68 68 67 65 65
0 62 66 66 64 0 57 61 59 56 0 65 67 65 65
2
3
%
GMT (mlU/ml)
92.5 100.0 100.0 100.0
244 532 410 4257
91.9 98.4 100.0 100.0
304 498 368 4097
95.6 100.0 100.0 100.0
281 577 427 4387
had developed anti-HAV antibodies and one month after the second injection all but one vaccinee had seroconverted (Table 1). The latter subject had seroconverted by month 6. After month 2, one month after the second injection, the titre of antibodies decreased only slightly until month 6. The booster injection given at that time resulted in a more than tenfold increase in antibody titre. There was no difference with respect to side effects or immunogenicity of the three lots of vaccine.
DISCUSSION The prevalence of anti-HAV antibodies in sera from Western European individuals has decreased significantly in recent years 7. More than 90% of individuals younger than 30 years lack protective antibodies. As this age group comprises the most active travellers to areas in which HAV infection is endemic, long-term and reliable protection appears to be necessary. Active immunization would be the most suitable protection against HAV infection for such individuals. Our study shows that the newly developed HAV vaccine is a good candidate for this purpose. As early as one month after the second injection, all but one vaccinee had protective anti-HAV antibodies. This person had, however, developed antibodies by month 6. Thus, all vaccinees responded to the vaccine, irrespective of the lot used, and all lots studied appeared to be comparable with respect to immunogenicity and reactogenicity. Side effects were minor in all three groups, although a rate of 30% appears at first sight to be high. It has to be stressed, however, that all participants were asked thoroughly for all possible side effects, thus probably leading to an overestimation. Discomfort and pain at the site of injection were the most frequent complaints. The observed rate, however, appears to be comparable to rates recorded in studies using other similar vaccines, as for example hepatitis B vaccines 8. Two individuals showed a transient rise in serum transaminases. This cannot be attributed to the vaccine, as such events are
Vaccine, Vol. 10, Suppl. 1, 1992
$133
R e a c t o g e n i c i t y a n d i m m u n o g e n i c i t y o f hepatitis A vaccine: L. T h e i l m a n n et al.
observed with a similar frequency in the general population ~. In summary, the three consecutive lots of the HAV vaccine tested, were all equally highly immunogenic and vaccination was accompanied by only minor side effects. We therefore conclude that the vaccine is safe, well tolerated and suitable for the prophylaxis of HAV infection.
REFERENCES Steffen, R. Reisemedizin. Springer, Heidelberg, 1984, pp. 90-96 Lemon, S. Type A viral hepatitis. N EngL J. Med. 1985, 313, 1059-1067 Szmuness, W., Dienstag, J., Purcell, R.H., Stevens, C., Wong, D.C., Ikram, H., Bar-Shangs, S., Beasley, R.P., Desmyter, J. and Gaon, J.A. The prevalence of antibody to hepatitis A antigen in various of the world: a pilot study. Am. J. EpidemioL 1977, 106, 392~.398
S134
Vaccine, Vol. 10, Suppl. 1, 1992
Fr6sner, G.G. Epidemiology of hepatitis A. Viral Hepatitis (Ed Deinhardt, F.) Marcel Dekker, New York, 1983, pp. 201-212 5 Andre, F., Hepburn, A. and D'Hondt, E. Inactivated candidate vaccines for hepatitis A. Prog. Med. ViroL 1990, 37, 72-95 6 Delem, A., Denamur, F. and D'Hondt, E. Serum antibodies response to HAV-killed vaccine: correlation between three methods of titration. International Symposium on Viral Hepatitis and Liver Disease, Houston, USA, 4-8 Apr 1990 (abstract) 7 Fr6sner, G.G., Papaevangelou, G., Butler,R, Iwarson, S., Linholm, A., Courource-Pauty, A., Haas, H. and Deinhardt, F. Antibody against hepatitis A in seven European countries. Am. J. EpidemioL 1979, 110, 63q38 8 Andre, F. Overview of a 5--year clinical experience with yeast derived hepatitis B vaccines. Vaccine 1990, 8 (Suppl.), 74.-78 9 Sherman, K.E., Dodd, R.Y. and the American Red Cross Aminotransferase Study Group. Alanine aminotransferase levels among volunteer blood donors: geographic variation and risk factors: J. Infect. Dis. 1982, 145, 383-386 4
