Chapter 2 : History of Pneumococcal Immunization

MyBook is a cheap paperback edition of the original book and will be sold at uniform, low price.

Preview this chapter:
Zoom in

History of Pneumococcal Immunization, Page 1 of 2

| /docserver/preview/fulltext/10.1128/9781555815820/9781555814083_Chap02-1.gif /docserver/preview/fulltext/10.1128/9781555815820/9781555814083_Chap02-2.gif


By the year 1800, 200 years ago, the smallpox vaccine had established the principle of preventing serious disease by active immunization. In the 1940s, these whole-cell vaccines were supplanted by the next generation of pneumococcal vaccines, which consisted of the purified capsular polysaccharides (PS) of the bacteria. As early as 1891, animal experiments showed that killed pneumococci elicited protective immunity to subsequent challenge with virulent bacteria. The influenza pandemic of 1918 to 1919, together with the First World War, created a situation conducive to a highly increased incidence of pneumococcal pneumonia. Researchers administered a trivalent vaccine to 12,519 men in training at the United States. The results of the trials with the killed whole-cell vaccines were considered very encouraging at the time. Even a 30% reduction in numbers of cases of lobar pneumonia was welcomed because there were no alternative prevention measures. The experimental research of Avery, Heidelberger, and Goebel in the 1920s formed the essential links between pneumococcal capsules, their serotype specificity, and the identity of the capsules with PS that could be isolated from the bacterial cultures by chemical means. Despite recommendations for routine of pneumococcal immunization at-risk populations, the uptake of the vaccine was relatively slow. Nearly 10 years after the licensure of PS vaccine in the United States, only 10% of persons for whom the vaccine was recommended had ever been immunized. Protection against pneumococcal bacteremia, provided by the 23-valent PS vaccine, wanes over a period of 3 to 5 years, particularly in older people.

Citation: Mäkelä P, Butler J. 2008. History of Pneumococcal Immunization, p 19-29. In Siber G, Klugman K, Mäkelä P (ed), Pneumococcal Vaccines. ASM Press, Washington, DC. doi: 10.1128/9781555815820.ch2
Highlighted Text: Show | Hide
Loading full text...

Full text loading...


1. Austrian, R. 1984. A reassessment of pneumococcal vaccine. N. Engl. J. Med. 310: 651653.
2. Austrian, R.,, R. M. Douglas,, G. Schiffman,, A. M. Coetzee,, H. J. Koornhof,, S. Hayden-Smith, and, R. D. Reid. 1976. Prevention of pneumococcal pneumonia by vaccination. Trans. Assoc. Am. Physicians 89: 184194.
3. Austrian, R., and, J. Gold. 1964. Pneumococcal bacteremia with especial reference to bacteremic pneumococcal pneumonia. Ann. Intern. Med. 60: 759776.
4. Avery, O., and, M. Heidelberger. 1925. Immunological relationships of cell constituents of pneumococcus. J. Exp. Med. 42: 367376.
5. Avery, O., and, H. Morgan. 1925. Immunological reactions of the isolated carbohydrate and protein of pneumococcus. J. Exp. Med. 42: 347353.
6. Avery, O. T., and, W. F. Goebel. 1931. Chemo-immunological studies on conjugated carbohydrate-proteins. V. The immunological specificity of an antigen prepared by combining the capsular polysaccharide of type III pneumococcus with foreign protein. J. Exp. Med. 54: 437447.
7. Benin, A. L.,, K. L. O’Brien,, J. P. Watt,, R. Reid,, E. R. Zell,, S. Katz,, C. Donaldson,, A. Parkinson,, A. Schuchat,, M. Santosham, and, C. G. Whitney. 2003. Effectiveness of the 23-valent polysaccharide vaccine against invasive pneumococcal disease in Navajo adults. J. Infect. Dis. 188: 8189.
8. Breiman, R. F.,, D. W. Keller,, M. A. Phelan,, D. H. Sniadack,, D. S. Stephens,, D. Rimland,, M. M. Farley,, A. Schuchat, and, A. L. Reingold. 2000. Evaluation of effectiveness of the 23-valent pneumococcal capsular polysaccharide vaccine for HIV-infected patients. Arch. Intern. Med. 160: 26332638.
9. Brichacek, B.,, S. Swindells,, E. N. Janoff,, S. Pirruccello, and, M. Stevenson. 1996. Increased plasma human immunodeficiency virus type 1 burden following antigenic challenge with pneumococcal vaccine. J. Infect. Dis. 174: 11911199.
10. Broome, C. V. 1981. Efficacy of pneumococcal polysaccharide vaccines. Rev. Infect. Dis. 3 (Suppl.): S82S96.
11. Broome, C. V., and, R. R. Facklam. 1981. Epidemiology of clinically significant isolates of Streptococcus pneumoniae in the United States. Rev. Infect. Dis. 3: 277281.
12. Bush, C. E.,, R. M. Donovan,, N. P. Markowitz,, P. Kvale, and, L. D. Saravolatz. 1996. A study of HIV RNA viral load in AIDS patients with bacterial pneumonia. J. Acquir. Immune Defic. Syndr. Hum. Retrovirol. 13: 23–26.
13. Butler, J. C.,, R. F. Breiman,, J. F. Campbell,, H. B. Lipman,, C. V. Broome, and, R. R. Facklam. 1993. Pneumococcal polysaccharide vaccine efficacy. An evaluation of current recommendations. JAMA 270: 18261831.
14. Butler, J. C.,, R. F. Breiman,, J. F. Campbell,, H. B. Lipman,, C. V. Broome, and, R. R. Facklam. 1993. Pneumococcal polysaccharide vaccine efficacy. An evaluation of current recommendations. JAMA 270: 18261831.
15. Cecil, R. L., and, J. H. Austin. 1918. Results of prophylactic inoculation against pneumococcus in 12,519 men. J. Exp. Med. 28: 1941.
16. Cecil, R. L., and, H. F. Vaughan. 1919. Results of prophylactic vaccination against pneumonia at Camp Wheeler. J. Exp. Med. 29: 457483.
17. Centers for Disease Control and Prevention. 2006. Influenza and pneumococcal vaccination coverage among persons aged ≥ 65 years—United States, 2004–2005. Morb. Mortal. Wkly. Rep. 55: 10651068.
18. Centers for Disease Control and Prevention. 1981. Pneumococcal polysaccharide vaccine. Morb. Mortal. Wkly. Rep. 30: 410412, 417419.
19. Centers for Disease Control and Prevention. 1989. Pneumococcal polysaccharide vaccine. Morb. Mortal. Wkly. Rep. 38: 6468, 7376.
20. Centers for Disease Control and Prevention. 1997. Prevention of pneumococcal disease: recommendations of the Advisory Committee on Immunization Practices (ACIP). Morb. Mortal. Wkly. Rep. 46: 124.
21. Centers for Disease Control and Prevention. 1984. Update: pneumococcal polysaccharide vaccine usage—United States. Morb. Mortal. Wkly. Rep. 33: 273276, 281.
22. Conaty, S.,, L. Watson,, J. Dinnes, and, N. Waugh. 2004. The effectiveness of pneumococcal polysaccharide vaccines in adults: a systematic review of obervational studies and comparison with results from randomized controlled trials. Vaccine 22: 32143224.
23. Dochez, A. R., and, L. J. Gillespie. 1913. A biologic classification of pneumococci by means of immunity reactions. JAMA 61: 727732.
24. Douglas, R.,, D. Hansman,, H. Miles, and, J. Pton. 1986. Pneumococcal carriage and type-specific antibody. Failure of a 14-valent vaccine to reduce carriage in healthy children. Am. J. Dis. Child. 140: 11831185.
25. Douglas, R.,, J. Paton,, S. Duncan, and, D. Hansman. 1983. Antibody response to pneumococcal vaccination in children younger than five years of age. J. Infect. Dis. 148: 131137.
26. Ekwurzel, G. M.,, J. S. Simmons,, L. I. Dublin, and, L. D. Felton. 1938. Studies on immunizing substances in pneumococci. VIII. Report on field tests to determine the prophylactic value of a pneumococcus antigen. Public Health Rep. (Washington) 53: 18771893.
27. Farr, B. M.,, B. L. Johnston,, D. K. Cobb,, M. J. Fisch,, T. P. Germanson,, K. A. Adal, and, A. M. Anglim. 1995. Preventing pneumococcal bacteremia in patients at risk. Results of a matched case-control study. Arch. Intern. Med. 155: 23362340.
28. Fedson, D.,, J. Henrichsen,, P. H. Makela, and, R. Austrian. 1989. Immunization of elderly people with polyvalent pneumococcal vaccine. Infection 17: 437441.
29. Fedson, D. S. 1998. Pneumococcal vaccination in the United States and 20 other developed countries, 1981–1996. Clin. Infect. Dis. 26: 11171123.
30. Felton, L. 1938. Studies on immunizing substances in pneumococci. VII. Response in human beings to antigenic pneumococcal polysacharides, types I and II. Public Health Rep. 53: 18551877.
31. Fine, M. J.,, M. A. Smith,, C. A. Carson,, F. Meffe,, S. S. Sankey,, L. A. Weissfeld,, A. S. Detsky, and, W. N. Kapoor. 1994. Efficacy of pneumococcal vaccination in adults. A meta-analysis of randomized controlled trials. Arch. Intern. Med. 154: 26662677.
32. Francis, T., and, W. Tillett. 1930. Cutaneous reactions in pneumonia. The development of antibodies following the intradermal injection of type-specific polysaccharide. J Exp. Med. 52: 573585.
33. French, N.,, J. Nakiyingi,, L. M. Carpenter,, E. Lugada,, C. Watera,, K. Moi,, M. Moore,, D. Antvelink,, D. Mulder,, E. N. Janoff,, J. Whitworth, and, C. F. Gilks. 2000. 23-Valent pneumococcal polysaccharide vaccine in HIV-1-infected Ugandan adults: double-blind, randomised and placebo controlled trial. Lancet 355: 21062111.
34. Fry, A. M.,, E. R. Zell,, A. Schuchat,, J. C. Butler, and, C. G. Whitney. 2002. Comparing potential benefits of new pneumococcal vaccines with the current polysaccharide vaccine in the elderly. Vaccine 21: 303311.
35. Givon-Lavi, N.,, D. Fraser, and, R. Dagan. 2003. Vaccination of day-care center attendees reduces carriage of Streptococcus pneumoniae among their younger siblings. Pediatr. Infect. Dis. J. 22: 524532.
36. Goebel, W. F.,, O. T. Avery, and, F. H. Babers. 1934. Chemo-immunological studies on conjugated carbohydrate-proteins. IX. The specificity of antigens prepared by combining the paminophenol glycosides of disaccharides with protein. J. Exp. Med. 60: 599617.
37. Hammitt, L. L.,, D. L. Bruden,, J. C. Butler,, H. C. Baggett,, D. A. Hurlburt,, A. Reasonover, and, T. W. Hennessy. 2006. Indirect effect of conjugate vaccine on adult carriage of Streptococcus pneumoniae: an explanation of trends in invasive pneumococcal disease. J. Infect. Dis. 193: 14871494.
38. Hansman, D., and, M. M. Bullen. 1967. A resistant pneumococcus. Lancet ii: 264265.
39. Heidelberger, M., and, O. T. Avery. 1923. The soluble specific substance of pneumococcus. J. Exp. Med. 38: 7379.
40. Heidelberger, M.,, C. M. MacLeod, and, M. M. Di Lapi. 1948. The human antibody response to simultaneous injection of six specific polysaccharides of pneumococcus. J. Exp. Med. 88: 369372.
41. Hilleman, M. R.,, A. J. Carlson, Jr.,, A. A. McLean,, P. P. Vella,, R. E. Weibel, and, A. F. Woodhour. 1981. Streptococcus pneumoniae polysaccharide vaccine: age and dose responses, safety, persistence of antibody, revaccination, and simultaneous administration of pneumococcal and influenza vaccines. Rev. Infect. Dis. 3 (Suppl.): S31S42.
42. Honkanen, P. O.,, T. Keistinen,, L. Miettinen,, E. Herva,, U. Sankilampi,, E. Laara,, M. Leinonen,, S. L. Kivela, and, P. H. Makela. 1999. Incremental effectiveness of pneumococcal vaccine on simultaneously administered influenza vaccine in preventing pneumonia and pneumococcal pneumonia among persons aged 65 years or older. Vaccine 17: 24932500.
43. Jackson, L.,, P. Benson,, V.-P. Sneller,, J. Butler,, R. Thompson,, R. Chen,, L. Lewis,, G. Carlone,, F. DeStefano,, P. Holder,, T. Lezhava, and, W. Williams. 1999. Safety of re-vaccination with pneumococcal polysaccharide vaccine. JAMA 281: 243248.
44. Jackson, L. A.,, K. M. Neuzil,, O. Yu,, P. Benson,, W. E. Barlow,, A. L. Adams,, C. A. Hanson,, L. D. Mahoney,, D. K. Shay, and, W. W. Thompson. 2003. Effectiveness of pneumococcal polysaccharide vaccine in older adults. N. Engl. J. Med. 348: 17471755.
45. Jacobs, M. R.,, H. J. Koornhof,, R. M. Robins–Browne,, C. M. Stevenson,, Z. A. Vermaak,, I. Freiman,, G. B. Miller,, M. A. Witcomb,, M. Isaacson,, J. I. Ward, and, R. Austrian. 1978. Emergence of multiply resistant pneumococci. N. Engl. J. Med. 299: 735740.
46. Jordan, E. O., and, W. B. Sharp. 1921. Influenza studies. IV. Effect of vaccination against influenza and some other respiratory infections. J. Infect. Dis. 28: 357366.
47. Karma, P.,, J. Pukander,, M. Sipila,, M. Timonen,, S. Pontynen,, E. Herva,, P. Gronroos, and, H. Makela. 1985. Prevention of otitis media in children by pneumococcal vaccination. Am. J. Otolaryngol. 6: 173184.
48. Kilpi, T.,, E. Herva,, T. Kaijalainen,, R. Syrjanen, and, A. K. Takala. 2001. Bacteriology of acute otitis media in a cohort of Finnish children followed for the first two years of life. Pediatr. Infect. Dis. J. 20: 654662.
49. Klein, J.,, D. Teele, and, S. Pelton. 1992. New concepts in otitis media: results of investigations of the Greater Boston Otitis Media Study Group. Adv. Pediatr. 39: 127156.
50. Klemperer, G., and, F. Klemperer. 1891. Versuche uber immunisierung und Heilung bei der Pneumokokkeninfection. Berl. Klin. Wochenschr. 28: 830835.
51. Kneeland, Y. 1924. The protection afforded by vaccination against secondary invaders during colds in infancy. J. Exp. Med. 69: 655660.
52. Koskela, M. 1986. First and second dose antibody responses to pneumococcal polysaccharide vaccine in infants. Pediatr. Infect. Dis. 5: 4550.
53. Lehmann, D.,, T. F. Marshall,, I. D. Riley, and, M. P. Alpers. 1991. Effect of pneumococcal vaccine on morbidity from acute lower respiratory tract infections in Papua New Guinean children. Ann. Trop. Paediatr. 11: 247257.
54. Lister, F. S. 1917. Prophylactic inoculation of man against pneumococcal infections, and more particularly against lobar pneumonia; including a report upon the results of the experimental inoculation, with a specific group vaccine, of the native mine labourers employed upon the Premier (diamond) mine and the Crown (gold) mines in the Transvaal and the De Beers (diamond) mines at Kimberley—covering the period from November 1, 1916 to October 31, 1917. Publ. S. Afr. Inst. Med. Res. 1917.i.10: 303332.
55. Lister, F. S. 1913. Specific serological reactions with pneumococci from different sources. Publ. S. Afr. Inst. Med. Res. 1: 103116.
56. Lister, S. 1929. A note on the aetiology of epidemic inluenza and secondary pneumonia. J. Med. Assoc. S. Afr. 3: 179181.
57. Lister, S., and, D. Ordman. 1935. The epidemiology of pneumonia on the Witwatersrand goldfields and the prevention of pneumonia and other allied acute respiratory diseases in native labourers in South Africa by means of vaccine. Publ. S. Afr. Inst. Med. Res. 7: 181.
58. Luotonen, J. 1982. Streptococcus pneumoniae and Haemophilus influenzae in nasal cultures during acute otitis media. Acta Otolaryngol. 93: 295299.
59. MacLeod, C. M.,, R. G. Hodges,, M. Heidelberger, and, W. G. Bernhard. 1945. Prevention of pneumococcal pneumonia by immunization with specific capsular polysaccharides. J. Exp. Med. 82: 445465.
60. Mangtani, P.,, F. Cutts, and, A. J. Hall. 2003. Efficacy of polysaccharide pneumococcal vaccine in adults in more developed countries: the state of the evidence. Lancet Infect. Dis. 3: 7178.
61. Maynard, G. 1913. An enquiry into the etiology, manifestations, and prevention of pneumonia amongst natives on the Rand recruited from “tropical areas.” Publ. S. Afr. Inst. Med. Res. 1: 1101.
62. Maynard, G. 1915. Pneumonia inoculation experiment no. III. Med. J. S. Afr. 11: 3638.
63. Melegaro, A., and, W. J. Edmunds. 2004. The 23–valent pneumococcal polysaccharide vaccine. Part I. Efficacy of PPV in the elderly: a comparison of metanalyses. Eur. J. Epidemiol. 19: 353363.
64. Office of Technology Assessment, U.S. Congress. 1979. A Review of Selected Federal Vaccine and Immunization Policies: Based on Case Studies of Pneumococcal Vaccine. Office of Technology Assessment, U.S. Congress, Washington, DC.
65. Orenstein, A. J. 1931. Vaccine prophylaxis in pneumonia. J. Med. Assoc. S. Afr. 5: 339346.
66. Örtqvist, A.,, J. Hedlund,, L. A. Burman,, E. Elbel,, M. Hofer,, M. Leinonen,, I. Lindblad,, B. Sundelof, and, M. Kalin, et al. 1998. Randomised trial of 23-valent pneumococcal capsular polysaccharide vaccine in prevention of pneumonia in middle-aged and elderly people. Lancet 351: 399403.
67. Riley, I. D.,, F. A. Everingham,, D. E. Smith, and, R. M. Douglas. 1981. Immunisation with a polyvalent pneumococcal vaccine. Effect on respiratory mortality in children living in the New Guinea highlands. Arch. Dis. Child. 56: 354357.
68. Riley, I. D.,, D. Lehmann,, M. P. Alpers,, T. F. Marshall,, H. Gratten, and, D. Smith. 1986. Pneumococcal vaccine prevents death from acute lower-respiratory-tract infections in Papua New Guinean children. Lancet ii: 877881.
69. Riley, I. D.,, P. I. Tarr,, M. Andrews,, M. Pfeiffer,, R. Howard,, P. Challands, and, G. Jennison. 1977. Immunisation with a polyvalent pneumococcal vaccine. Reduction of adult respiratory mortality in a New Guinea Highlands community. Lancet i: 13381341.
70. Robbins, J. B.,, R. Austrian,, C. J. Lee,, S. C. Rastogi,, G. Schiffman,, J. Henrichsen,, P. H. Makela,, C. V. Broome,, R. R. Facklam,, R. H. Tiesjema, et al. 1983. Considerations for formulating the second-generation pneumococcal capsular polysaccharide vaccine with emphasis on the cross-reactive types within groups. J. Infect. Dis. 148: 11361159.
71. Robbins, J. B.,, C.-J. Lee,, S. Rastogi,, G. Schiffman, and, J. Henrichsen. 1979. Comparative immunogenicity of group 6 pneumococcal type 6A(6) and type 6B(26) capsular polysaccharides. Infect. Immun. 26: 11161122.
72. Robertson, O. H., and, R. H. P. Sia. 1924. Studies on pneumococcus growth inhibition. II. A method for demonstrating the growth-inhibitory and bactericidal action of normal serumleucocyte mixtures. J. Exp. Med. 39: 219245.
73. Rosenow, E. C., and, B. F. Sturdivant. 1919. Studies in influenza and pneumonia. IV. Further results of prophylactic inoculations. JAMA 73: 396401.
74. Schaffner, W.,, W. M. Schreiber, and, M. G. Koenig. 1966. Fatal pneumonia due to a tetracycline-resistant pneumococcus. N. Engl. J. Med. 274: 451452.
75. Schiemann, O., and, W. Casper. 1927. Sind die spezifisch präcipitablen Substanzen der 3 Pneumokokkentypen Haptene? Z. Hyg. Infektrankh. 108: 220257.
76. Sell, S.,, P. Wright,, W. Vaughn,, J. Thompson, and, G. Schiffman. 1981. Clinical studies of pneumococcal vaccines in infants. I. Reactogenicity and immunogenicity of two polyvalent polysaccharide vaccines. Rev. Infect. Dis. 3: S97S107.
77. Shapiro, E. D.,, A. T. Berg,, R. Austrian,, D. Schroeder,, V. Parcells,, A. Margolis,, R. K. Adair, and, J. D. Clemens. 1991. The protective efficacy of polyvalent pneumococcal polysaccharide vaccine. N. Engl. J. Med. 325: 14531460.
78. Siegel, M., and, R. Muckenfuss. 1941. A study in active immunization against epidemic influenza and pneumococcus pneumonia at Letchworth Village. II. Results of active immunization against pneumonia with pneumococcal polysaccharide. Am. J. Hyg. 34: 79109.
79. Simberkoff, M. S.,, A. P. Cross,, M. Al-Ibrahim,, A. L. Baltch,, P. J. Geiseler,, J. Nadler,, A. S. Richmond,, R. P. Smith,, G. Schiffman,, D. S. Shepard, et al. 1986. Efficacy of pneumococcal vaccine in high-risk patients. Results of a Veterans Administration Cooperative Study. N. Engl. J. Med. 315: 13181327.
80. Sisk, J. E.,, A. J. Moskowitz, W. Whang, J. D. Lin, D. S. Fedson, A. M. McBean, J. F. Plouffe, M. S. Cetron, and J. C. Butler. 1997. Cost-effectiveness of vaccination against pneumococcal bacteremia among elderly people. JAMA 278: 13331339.
81. Sisk, J. E.,, W. Whang,, J. C. Butler,, V. P. Sneller, and, C. G. Whitney. 2003. Cost-effectiveness of vaccination against invasive pneumococcal disease among people 50 through 64 years of age: role of comorbid conditions and race. Ann. Intern. Med. 138: 960968.
82. Sloyer, J. L., Jr.,, J. H. Ploussard, and, V. M. Howie. 1981. Efficacy of pneumococcal polysaccharide vaccine in preventing acute otitis media in infants in Huntsville, Alabama. Rev. Infect. Dis. 3 (Suppl.): S119S123.
83. Smit, P.,, D. Oberholzer,, S. Hayden-Smith,, H. J. Koornhof, and, M. R. Hilleman. 1977. Protective efficacy of pneumococcal polysaccharide vaccines. JAMA 238: 26132616.
84. Sörensen, U., and, J. Henrichsen. 1984. C-polysaccharide in a pneumococcal vaccine. Acta. Pathol. Microbiol. Immunol. Scand. C 92: 351356.
85. Stanley, S. K.,, M. A. Ostrowski,, J. S. Justement,, K. Gantt,, S. Hedayati,, M. Mannix,, K. Roche,, D. J. Schwartzentruber,, C. H. Fox, and, A. S. Fauci. 1996. Effect of immunization with a common recall antigen on viral expression in patients infected with human immunodeficiency virus type 1. N. Engl. J. Med. 334: 12221230.
86. U.S. Department of Health and Human Services. 2000. Healthy People 2010: Understanding and Improving Health, 2nd ed. U.S. Department of Health and Human Services, Washington, DC.
87. von Sholly, A. I., and, W. H. Park. 1921. Report on the prophylactic vaccination of 1536 persons against acute respiratory diseases, 1919–1920. J. Immunol. 6: 103115.
88. Walker, F. J.,, R. J. Singleton,, L. R. Bulkow,, R. A. Strikas, and, J. C. Butler. 2005. Reactions after 3 or more doses of pneumococcal polysaccharide vaccine in adults in Alaska. Clin. Infect. Dis. 40: 17301735.
89. Whitney, C. G.,, W. Schaffner, and, J. C. Butler. 2001. Rethinking recommendations for use of pneumococcal vaccines in adults. Clin. Infect. Dis. 33: 662675.
90. Williams, B.,, E. Gouws,, C. Boschi-Pinto,, J. Bryce, and, C. Dye. 2002. Estimates of world-wide distribution of child deaths from acute respiratory infections. Lancet Infect. Dis. 2: 2532.
91. Williams, W.,, M. Hickson,, M. Kane,, A. Kendal,, J. Spika, and, A. Hinman. 1988. Immunization policies and vaccine coverage among adults. Ann. Intern. Med. 108: 616625.
92. Wright, A. E.,, W. P. Morgan,, L. Colebrook, and, R. W. Dodgson. 1914. Prophylactic inoculation against pneumococcus infections. Lancet i: 110, 8795.
93. Zon, G.,, S. C. Szu,, W. Egan,, J. D. Robbins, and, J. B. Robbins. 1982. Hydrolytic stability of pneumococcal group 6 (type 6A and 6B) capsular polysaccharides. Infect. Immun. 37: 89103.

This is a required field
Please enter a valid email address
Please check the format of the address you have entered.
Approval was a Success
Invalid data
An Error Occurred
Approval was partially successful, following selected items could not be processed due to error