THE JOURNAL OF INFECTIOUS DISEASE. VOL. 136, SUPPLEMENT. DECEl\1BER 1977 © 1977 by the University of Chicago. All rights reserved.
Reactions and Serologic Responses after Administration of Inactivated Monovalent Influenza A/Swine Virus Vaccines. I. Immunization of Children and Adults with Influenza A/Shope Virus Vaccines Paul B. Welty, Jr., Bruce Epstein, John O'Brien, Robert G. Brackett, Frank B. Brandon, and Joan L. Shillis
From Welty, Epstein, and O'Brien, M.D.'s, P.A., St. Petersburg, Florida; and the Department of Biological Research and Development, Parke, Davis and Company, Detroit, Michigan
In the past, routine immunization against influenza virus was not recommended for healthy children because vaccines were variably effective. Also, there were unacceptably high levels of febrile and other systemic reactions in relation to low rates of morbidity and mortality in children infected with influenza virus [1]. To counter these problems, workers at Parke, Davis and Company (PD; Detroit, Mich.) developed a procedure using ether to remove lipid from the virion and to disrupt the particle, combined with zonal centrifugation and molecular sieving [2]. Subunit or split-virus vaccines prepared by this process exhibited significantly fewer systemic and local reactions in adults [3] and impressively reduced febrile reactions in children [4]. Although the reactivity differential between whole-virus and subunit virus vaccines was beWe acknowledge Dr. William Beardmore's contribution in the preparation of the experimental vaccines used in this study. Please address requests for reprints to Dr. Robert G. Brackett, Clinical Immunology, Parke, Davis and Company, Joseph Campau at the River, Detroit, Michigan
48232.
ing studied in the National Influenza Vaccine Test Program (IVTP) [5], the vaccines used in the IVTP were provided by different manufacturers, and administration of only a single dose of vaccine to each subject had been planned. It seemed important, therefore, to compare in children given a two-dose regimen the two types of vaccine derived from aliquots of a single pool of parent virus. Such vaccines were prepared by PD from a single pool, and acorn parative study was initiated in unison with, but independent of, the IVTP. Materials and Methods
Vaccines. The first series of influenza A/swine virus vaccines was prepared by PD from the A / New Jersey /8/76 virus seed. This virus, when cultured through a total of 10 egg passages, proved to be antigenically more like the influenza A/ swine /1976/31 (HswlNl) virus isolated from pigs by Dr. R. E. Shope in 1931 [6] than the influenza A/New Jersey virus isolated from recruits at Fort Dix, N. ]. [5]. This virus will be referred to throughout this paper as A/Shope.
8604
Downloaded from http://jid.oxfordjournals.org/ by guest on August 11, 2015
Reactivity and immunogenicity of three inactivated, zonally purified, monovalent influenza A/swine virus vaccines were studied in children and adults. Each dose of vaccine contained either 400 chick cell-agglutinating (CCA) units/O.5 ml or 200 CCA units/O.25 ml. The vaccines contained either whole virus or ether-extracted, subunit virus with or without 1.5 mg of AIP0 4/O.5 ml. Children younger than 10 years of age received a half dose. Substantial systemic reactions, including temperature increases of 2.2 F-4.9 F, were observed in all children who received wholevirus vaccines. In contrast, ether-extracted, subunit vaccines (with or without AIP0 4 ) were minimally pyrogenic in 185 subjects. Two doses of subunit vaccine in subjects younger than 25 years of age were immunologically equivalent to a single dose in older subjects. We concluded that two doses of ether-extracted, subunit virus vaccine with Hsw l Nl antigen, administered at least four weeks apart, are serologically effective for immunization of seronegative subjects of any age and that this dosage regimen should be used in young children in whom whole-virus vaccines are unacceptably reactive.
Reactions and Serologic Response to A / Swine 1
5605
°
Table 1. Distribution of subjects by age and type of vaccine administered.
Age in years (no. of subjects) 6-9 (37) 10-20 (66) 21-30 (16) 31-40 (59) 41-50 (13) ~51 (4) Total (195)
A/Shope subunit virus vaccine Fluid
A/Shope whole-virus, fluid vaccine A1P04
21 33 6 26 6 1
13 31 32 5 3
3 2 2 1 2 0
93
92
10
8
NOTE. Data given are number of subjects. The vaccines contained either no adjuvant (fluid) or the adjuvant A1P04' Vaccines were administered im to the six- to nine-year-old children in doses of 0.25 ml (200 chick cell-agglutinating [CCA] units) and to those 10 years old or older in doses of 0.5 ml (400 CCA units).
tered im: doses of 0.25 ml (200 CCA units) to the six- to nine-year-old children and 0.5 ml (400 CCA units) to those 10 years old or older. Four weeks after administration of the first dose, identical doses of the same vaccine were given as a booster. Observations. All subjects were observed for both objective and subjective reactions to the vaccine. Parents were advised to call the physician in the event of an elevated temperature or any other "disturbing reaction." Oral temperatures were taken prior to immunization. Measurements of erythema and induration at the site of injection were made by the parents, who also recorded oral temperatures 24 and 48 hr after each immunization. Other information sought was the presence of pain or tenderness at the injection site, fever, aching, chills, headache, nausea, vomiting, and "other" symptoms. Serology. A l O-ml sample of blood was drawn at the start of the study and four and six weeks later. Serum was stored frozen at -20 C until tested. Following treatment with a receptor-destroying enzyme for removal of nonspecific inhibitors, samples of serum were assayed at PD for specific HAl antibodies to influenza A/ Shope and A/New Jersey /76/X-53 (A/NJ / X-53) viruses [7]. Only subjects from whom three samples of serum were obtained contributed to the data. Samples of sera from a portion of the subjects were submitted to the Center for Disease Control (CDC; Atlanta, Ga.) for confirmatory assays of HAl antibody. The identity of challenge antigens used in the HAl antibody assay was confirmed by tests with strain-specific ferret antisera. Results
Reactions to uihole-virus vaccine. Of approximately 30 subjects immunized during the first two days of the study, 10 received the fluid, wholevirus vaccine. Five of 10 subjects were adults older than 25 years whose reactions were unremarkable. The remaining five were children aged seven to 13 years. At some time during the 24-hr interval after vaccination, all five exhibited substantial increases in temperature (range, 2.2 F4.9 F), accompanied by mild-to-severe headache, nausea, and aching. All reactions were consid-
Downloaded from http://jid.oxfordjournals.org/ by guest on August 11, 2015
Three inactivated monovalent vaccines were studied, and each dose contained 400 chick cellagglutinating (CCA) units of antigen/O.5 ml. These vaccines were as follows: a zonally purified, whole-virus vaccine; and two zonally purified, ether-extracted, subunit virus vaccines, one with 1.5 mg of AIP0 4/ml and the other without the adjuvant, hereafter called the fluid, subunit vaccine. All vaccines were prepared from the same active pool of virus. Subjects. Healthy boys and girls, aged six to 18 years, from the private pediatric practice of Drs. P. B. Welty, Jr., B. Epstein, and J. O'Brien (St. Petersburg, Fla.), were the principal subjects. Any child who had a history of sensitivity to egg protein, who was experiencing an acute febrile illness, or who was receiving immunosuppressive drugs was excluded. Recruitment was by families; therefore, older siblings and parents participated in the study. Subjects ranged in age from six to 69 years, with 19% of them younger than 1 years. The distribution of subjects by age and type of vaccine administered is shown in table 1. There were 103 female and 92 male subjects. The parents of subjects who were minors and other adults were given an investigator's statement describing the study, and after an opportunity for discussion, a written informed consent was obtained from each of them. Subjects were assigned at random to one of the three vaccine groups. Vaccines were adminis-
Welty et al.
S606
the number of reports of fever decreased from 10 to two; of aching, from 17 to five; and of headache, from 23 to seven. Fewer subjects reported systemic reactions after 48 hr than did subjects 24 hr following both the first and second injections. Serological response to immunization with subunit vaccines. Complete sets of three samples of sera each were available from 173 subjects, including 34 aged six to nine years, who had received two 0.25-ml doses of vaccine (200 CCA units each), and 63 aged 10-24 years and 76 aged 25 years or older, who had received two 0.5-ml doses of vaccine (400 CCA units). Within each age group, the homologous HAl antibody response to fluid and AIP0 4 vaccines have been combined because no statistically significant difference between the two was observed. However, the GMT of HAl antibody in the sera of those subjects who received the AIP0 4 vaccine was higher than in those who received the fluid preparation. Figure 1 shows, by age group, the GMT of homologous antibody before, after the first, and after the second immunizations, combining both subunit vaccine groups. None of the subjects six to nine years old or 10-24 years old had titers of HAl antibody to influenza A/Shope
c:::::JP",nt., 160
~ Post 1st Voccinalion _Post2ndVoccinotion
80
10- 24 yeanln.63j AGE GROUP
Figure 1. Geometric mean titers of HAl antibody to influenza A/Shope virus in subjects aged six to nine years who were given 0.25-ml doses containing 200 chick cell-agglutinating (CCA) units and in subjects 10 years old or older who were given 0.5-ml doses containing 400 CCA units. Data are values before, after the first, and after the second immunization.
Downloaded from http://jid.oxfordjournals.org/ by guest on August 11, 2015
ered by the parents to be of sufficient severity to warrant notification of the physician. In view of these alarming observations, the investigators and the sponsors unanimously agreed to withdraw the whole-virus vaccine from the study. The geometric mean titer (GMT) of HAl antibody to influenza A/Shope virus in children after one immunization with whole-virus vaccine was 1:13, with titers of ~1:20 in two of five of these children. Reactions to subunit vaccine. One hundred eighty-five initial doses of fluid, subunit vaccine and subunit vaccine with the AIP0 4 adjuvant were administered, including 34 half doses to children younger than 10 years. Not a single reaction was reported to the physician. The statistical parameters of temperature change (from values before injection) after the first dose were analyzed. The subunit vaccines were minimally pyrogenic. The highest temperature attained (100.0 F) occurred in a sevenyear-old boy 48 hr after administration of the first dose. Febrile responses to fluid and AIP0 4 vaccines were not statistically different in any age group. Although not all parents provided 24and 48-hr temperature data, none of the missing reports were associated with reaction complaints; therefore, it seems reasonable to assume that the data available are representative of the overall response. With the exception of a relatively high rate of pain and/or tenderness at the site of injection, reactions were mild and infrequent. Soreness of the arm persisted longer and frequency of soreness was statistically greater in the subjects receiving AIP0 4 vaccine than in those receiving fluid vaccine. Otherwise, reactions to the vaccines were statistically equivalent. Two women, aged 36 and 37 years, respectively, had brief "asthma-like" reactions a few hours after immunization; one had received fluid and the other AIP0 4 vaccine. Both denied sensitivity to eggs. One had a childhood, but not a recent, history of asthma. The other had occasional episodes of mild asthmatic attacks. Both recovered spontaneously without medication. Within all age groups, local reactivity after the second dose was essentially equivalent to that after the first dose; however, reports of systemic reactions decreased sharply. For example,
5607
Reactions and Serologic Response to A / Swine I
Although reactivity limited administration of the whole-virus vaccine to a very small group, intolerance of the children to this product was in sharp contrast to the reaction of vaccinees who received the ether-extracted subunit vaccines, none of whom reported systemic reactions of clinical significance. This result with vaccines derived from a single pool of virus confirms earlier results with influenza virus type A (H2) and type B strains [4] and the finding of unacceptable reactivity, i.e., fever and other systemic reactions, that was observed in the governmentsponsored trials of whole-virus vaccines (A/NJ / 76) administered at levels of CCA units even lower thanthose used in our study [5]. The highest temperature reported for any subject inoculated with a subunit vaccine, 100.0 F, was in a child who had no other systemic symptoms. Whether it is significant that two adults developed wheezing a few hours after immu'nization with a subunit vaccine is not known. Parkman et al. [5] reported that only two of 3,982 adults exhibited expiratory wheezing in their studies of whole- and subunit virus vaccines. Follow-up results in December revealed no instance of central nervous system dysfunction in any vaccinee. c=JPreTiter
160
~PoltlJ.'VQ
Reactions and Serologic Responses after Administration of Inactivated Monovalent Influenza A/Swine Virus Vaccines. I. Immunization of Children and Adults with Influenza A/Shope Virus Vaccines Paul B. Welty, Jr., Bruce Epstein, John O'Brien, Robert G. Brackett, Frank B. Brandon, and Joan L. Shillis
From Welty, Epstein, and O'Brien, M.D.'s, P.A., St. Petersburg, Florida; and the Department of Biological Research and Development, Parke, Davis and Company, Detroit, Michigan
In the past, routine immunization against influenza virus was not recommended for healthy children because vaccines were variably effective. Also, there were unacceptably high levels of febrile and other systemic reactions in relation to low rates of morbidity and mortality in children infected with influenza virus [1]. To counter these problems, workers at Parke, Davis and Company (PD; Detroit, Mich.) developed a procedure using ether to remove lipid from the virion and to disrupt the particle, combined with zonal centrifugation and molecular sieving [2]. Subunit or split-virus vaccines prepared by this process exhibited significantly fewer systemic and local reactions in adults [3] and impressively reduced febrile reactions in children [4]. Although the reactivity differential between whole-virus and subunit virus vaccines was beWe acknowledge Dr. William Beardmore's contribution in the preparation of the experimental vaccines used in this study. Please address requests for reprints to Dr. Robert G. Brackett, Clinical Immunology, Parke, Davis and Company, Joseph Campau at the River, Detroit, Michigan
48232.
ing studied in the National Influenza Vaccine Test Program (IVTP) [5], the vaccines used in the IVTP were provided by different manufacturers, and administration of only a single dose of vaccine to each subject had been planned. It seemed important, therefore, to compare in children given a two-dose regimen the two types of vaccine derived from aliquots of a single pool of parent virus. Such vaccines were prepared by PD from a single pool, and acorn parative study was initiated in unison with, but independent of, the IVTP. Materials and Methods
Vaccines. The first series of influenza A/swine virus vaccines was prepared by PD from the A / New Jersey /8/76 virus seed. This virus, when cultured through a total of 10 egg passages, proved to be antigenically more like the influenza A/ swine /1976/31 (HswlNl) virus isolated from pigs by Dr. R. E. Shope in 1931 [6] than the influenza A/New Jersey virus isolated from recruits at Fort Dix, N. ]. [5]. This virus will be referred to throughout this paper as A/Shope.
8604
Downloaded from http://jid.oxfordjournals.org/ by guest on August 11, 2015
Reactivity and immunogenicity of three inactivated, zonally purified, monovalent influenza A/swine virus vaccines were studied in children and adults. Each dose of vaccine contained either 400 chick cell-agglutinating (CCA) units/O.5 ml or 200 CCA units/O.25 ml. The vaccines contained either whole virus or ether-extracted, subunit virus with or without 1.5 mg of AIP0 4/O.5 ml. Children younger than 10 years of age received a half dose. Substantial systemic reactions, including temperature increases of 2.2 F-4.9 F, were observed in all children who received wholevirus vaccines. In contrast, ether-extracted, subunit vaccines (with or without AIP0 4 ) were minimally pyrogenic in 185 subjects. Two doses of subunit vaccine in subjects younger than 25 years of age were immunologically equivalent to a single dose in older subjects. We concluded that two doses of ether-extracted, subunit virus vaccine with Hsw l Nl antigen, administered at least four weeks apart, are serologically effective for immunization of seronegative subjects of any age and that this dosage regimen should be used in young children in whom whole-virus vaccines are unacceptably reactive.
Reactions and Serologic Response to A / Swine 1
5605
°
Table 1. Distribution of subjects by age and type of vaccine administered.
Age in years (no. of subjects) 6-9 (37) 10-20 (66) 21-30 (16) 31-40 (59) 41-50 (13) ~51 (4) Total (195)
A/Shope subunit virus vaccine Fluid
A/Shope whole-virus, fluid vaccine A1P04
21 33 6 26 6 1
13 31 32 5 3
3 2 2 1 2 0
93
92
10
8
NOTE. Data given are number of subjects. The vaccines contained either no adjuvant (fluid) or the adjuvant A1P04' Vaccines were administered im to the six- to nine-year-old children in doses of 0.25 ml (200 chick cell-agglutinating [CCA] units) and to those 10 years old or older in doses of 0.5 ml (400 CCA units).
tered im: doses of 0.25 ml (200 CCA units) to the six- to nine-year-old children and 0.5 ml (400 CCA units) to those 10 years old or older. Four weeks after administration of the first dose, identical doses of the same vaccine were given as a booster. Observations. All subjects were observed for both objective and subjective reactions to the vaccine. Parents were advised to call the physician in the event of an elevated temperature or any other "disturbing reaction." Oral temperatures were taken prior to immunization. Measurements of erythema and induration at the site of injection were made by the parents, who also recorded oral temperatures 24 and 48 hr after each immunization. Other information sought was the presence of pain or tenderness at the injection site, fever, aching, chills, headache, nausea, vomiting, and "other" symptoms. Serology. A l O-ml sample of blood was drawn at the start of the study and four and six weeks later. Serum was stored frozen at -20 C until tested. Following treatment with a receptor-destroying enzyme for removal of nonspecific inhibitors, samples of serum were assayed at PD for specific HAl antibodies to influenza A/ Shope and A/New Jersey /76/X-53 (A/NJ / X-53) viruses [7]. Only subjects from whom three samples of serum were obtained contributed to the data. Samples of sera from a portion of the subjects were submitted to the Center for Disease Control (CDC; Atlanta, Ga.) for confirmatory assays of HAl antibody. The identity of challenge antigens used in the HAl antibody assay was confirmed by tests with strain-specific ferret antisera. Results
Reactions to uihole-virus vaccine. Of approximately 30 subjects immunized during the first two days of the study, 10 received the fluid, wholevirus vaccine. Five of 10 subjects were adults older than 25 years whose reactions were unremarkable. The remaining five were children aged seven to 13 years. At some time during the 24-hr interval after vaccination, all five exhibited substantial increases in temperature (range, 2.2 F4.9 F), accompanied by mild-to-severe headache, nausea, and aching. All reactions were consid-
Downloaded from http://jid.oxfordjournals.org/ by guest on August 11, 2015
Three inactivated monovalent vaccines were studied, and each dose contained 400 chick cellagglutinating (CCA) units of antigen/O.5 ml. These vaccines were as follows: a zonally purified, whole-virus vaccine; and two zonally purified, ether-extracted, subunit virus vaccines, one with 1.5 mg of AIP0 4/ml and the other without the adjuvant, hereafter called the fluid, subunit vaccine. All vaccines were prepared from the same active pool of virus. Subjects. Healthy boys and girls, aged six to 18 years, from the private pediatric practice of Drs. P. B. Welty, Jr., B. Epstein, and J. O'Brien (St. Petersburg, Fla.), were the principal subjects. Any child who had a history of sensitivity to egg protein, who was experiencing an acute febrile illness, or who was receiving immunosuppressive drugs was excluded. Recruitment was by families; therefore, older siblings and parents participated in the study. Subjects ranged in age from six to 69 years, with 19% of them younger than 1 years. The distribution of subjects by age and type of vaccine administered is shown in table 1. There were 103 female and 92 male subjects. The parents of subjects who were minors and other adults were given an investigator's statement describing the study, and after an opportunity for discussion, a written informed consent was obtained from each of them. Subjects were assigned at random to one of the three vaccine groups. Vaccines were adminis-
Welty et al.
S606
the number of reports of fever decreased from 10 to two; of aching, from 17 to five; and of headache, from 23 to seven. Fewer subjects reported systemic reactions after 48 hr than did subjects 24 hr following both the first and second injections. Serological response to immunization with subunit vaccines. Complete sets of three samples of sera each were available from 173 subjects, including 34 aged six to nine years, who had received two 0.25-ml doses of vaccine (200 CCA units each), and 63 aged 10-24 years and 76 aged 25 years or older, who had received two 0.5-ml doses of vaccine (400 CCA units). Within each age group, the homologous HAl antibody response to fluid and AIP0 4 vaccines have been combined because no statistically significant difference between the two was observed. However, the GMT of HAl antibody in the sera of those subjects who received the AIP0 4 vaccine was higher than in those who received the fluid preparation. Figure 1 shows, by age group, the GMT of homologous antibody before, after the first, and after the second immunizations, combining both subunit vaccine groups. None of the subjects six to nine years old or 10-24 years old had titers of HAl antibody to influenza A/Shope
c:::::JP",nt., 160
~ Post 1st Voccinalion _Post2ndVoccinotion
80
10- 24 yeanln.63j AGE GROUP
Figure 1. Geometric mean titers of HAl antibody to influenza A/Shope virus in subjects aged six to nine years who were given 0.25-ml doses containing 200 chick cell-agglutinating (CCA) units and in subjects 10 years old or older who were given 0.5-ml doses containing 400 CCA units. Data are values before, after the first, and after the second immunization.
Downloaded from http://jid.oxfordjournals.org/ by guest on August 11, 2015
ered by the parents to be of sufficient severity to warrant notification of the physician. In view of these alarming observations, the investigators and the sponsors unanimously agreed to withdraw the whole-virus vaccine from the study. The geometric mean titer (GMT) of HAl antibody to influenza A/Shope virus in children after one immunization with whole-virus vaccine was 1:13, with titers of ~1:20 in two of five of these children. Reactions to subunit vaccine. One hundred eighty-five initial doses of fluid, subunit vaccine and subunit vaccine with the AIP0 4 adjuvant were administered, including 34 half doses to children younger than 10 years. Not a single reaction was reported to the physician. The statistical parameters of temperature change (from values before injection) after the first dose were analyzed. The subunit vaccines were minimally pyrogenic. The highest temperature attained (100.0 F) occurred in a sevenyear-old boy 48 hr after administration of the first dose. Febrile responses to fluid and AIP0 4 vaccines were not statistically different in any age group. Although not all parents provided 24and 48-hr temperature data, none of the missing reports were associated with reaction complaints; therefore, it seems reasonable to assume that the data available are representative of the overall response. With the exception of a relatively high rate of pain and/or tenderness at the site of injection, reactions were mild and infrequent. Soreness of the arm persisted longer and frequency of soreness was statistically greater in the subjects receiving AIP0 4 vaccine than in those receiving fluid vaccine. Otherwise, reactions to the vaccines were statistically equivalent. Two women, aged 36 and 37 years, respectively, had brief "asthma-like" reactions a few hours after immunization; one had received fluid and the other AIP0 4 vaccine. Both denied sensitivity to eggs. One had a childhood, but not a recent, history of asthma. The other had occasional episodes of mild asthmatic attacks. Both recovered spontaneously without medication. Within all age groups, local reactivity after the second dose was essentially equivalent to that after the first dose; however, reports of systemic reactions decreased sharply. For example,
5607
Reactions and Serologic Response to A / Swine I
Although reactivity limited administration of the whole-virus vaccine to a very small group, intolerance of the children to this product was in sharp contrast to the reaction of vaccinees who received the ether-extracted subunit vaccines, none of whom reported systemic reactions of clinical significance. This result with vaccines derived from a single pool of virus confirms earlier results with influenza virus type A (H2) and type B strains [4] and the finding of unacceptable reactivity, i.e., fever and other systemic reactions, that was observed in the governmentsponsored trials of whole-virus vaccines (A/NJ / 76) administered at levels of CCA units even lower thanthose used in our study [5]. The highest temperature reported for any subject inoculated with a subunit vaccine, 100.0 F, was in a child who had no other systemic symptoms. Whether it is significant that two adults developed wheezing a few hours after immu'nization with a subunit vaccine is not known. Parkman et al. [5] reported that only two of 3,982 adults exhibited expiratory wheezing in their studies of whole- and subunit virus vaccines. Follow-up results in December revealed no instance of central nervous system dysfunction in any vaccinee. c=JPreTiter
160
~PoltlJ.'VQ
