Immunogenicity of recombinant BCG-based vaccine expressing the 22 kDa of serine repeat antigen (SE22) of Plasmodium falciparum

Tropical Biomedicine

Volumn 29, Issue 2, 2012, Pages 239-253

  Teo, W H ^a   Nurul, A A ^a   Norazmi, M N ^a  

^a SCHOOL OF HEALTH SCIENCES   (Malaysia)

Author keywords

[No Author keywords available]

Indexed keywords

BCG VACCINE; CYTOKINE; IMMUNOGLOBULIN G; LYMPHOCYTE PROLIFERATION POTENTIATING FACTORS; LYMPHOKINE; MALARIA VACCINE; PARASITE ANTIGEN; PROTOZOON ANTIBODY; RECOMBINANT VACCINE; SERINE REPEAT ANTIGEN, PLASMODIUM;

ANIMAL; ANTIBODY PRODUCTION; ARTICLE; BAGG ALBINO MOUSE; BLOOD; CD4+ T LYMPHOCYTE; CD8+ T LYMPHOCYTE; CELLULAR IMMUNITY; ENZYME LINKED IMMUNOSORBENT ASSAY; ESCHERICHIA COLI; FLUORESCENT ANTIBODY TECHNIQUE; GENETICS; HUMORAL IMMUNITY; IMMUNOLOGY; LYMPHOCYTE ACTIVATION; MALARIA FALCIPARUM; METABOLISM; MOLECULAR CLONING; MOUSE; PLASMODIUM FALCIPARUM;

ANIMALS; ANTIBODIES, PROTOZOAN; ANTIBODY FORMATION; ANTIGENS, PROTOZOAN; BCG VACCINE; CD4-POSITIVE T-LYMPHOCYTES; CD8-POSITIVE T-LYMPHOCYTES; CLONING, MOLECULAR; CYTOKINES; ENZYME-LINKED IMMUNOSORBENT ASSAY; ESCHERICHIA COLI; FLUORESCENT ANTIBODY TECHNIQUE, INDIRECT; IMMUNITY, CELLULAR; IMMUNITY, HUMORAL; IMMUNOGLOBULIN G; LYMPHOCYTE ACTIVATION; LYMPHOKINES; MALARIA VACCINES; MALARIA, FALCIPARUM; MICE; MICE, INBRED BALB C; PLASMODIUM FALCIPARUM; VACCINES, SYNTHETIC;

EID: 84866308797     PISSN: 01275720     EISSN: None     Source Type: Journal    
DOI: None     Document Type: Article

References (61)

1. Aidoo, M. & Udhayakumar, V. (2000). Field studies of cytotoxic T lymphocytes in malaria infections: implications for malaria vaccine development. Parasitology Today 16: 50-56.
2. Agnandji, S.T., Lell, B., Soulanoudjingar, S.S., Fernandes, J.F., Abossolo, B.P., Conzelmann, C., Methogo, B.G., Doucka, Y., Flamen, A., Mordmüller, B., Issifou, S., Kremsner, P.G., Sacarlal, J., Aide, P., Lanaspa, M., Aponte, J.J., Nhamuave, A., Quelhas, D., Bassat, Q., Mandjate, S., Macete, E., Alonso, P., Abdulla, S., Salim, N., Juma, O., Shomari, M., Shubis, K., Machera, F., Hamad, A.S., Minja, R., Mtoro, A., Sykes, A., Ahmed, S., Urassa, A.M., Ali, A.M., Mwangoka, G., Tanner, M., Tinto, H., D'Alessandro, U., Sorgho, H., Valea, I., Tahita, M.C., Kaboré, W., Ouédraogo, S., Sandrine, Y., Guiguemdé, R.T., Ouédraogo, J.B., Hamel, M.J., Kariuki, S., Odero, C., Oneko, M., Otieno, K., Awino, N., Omoto, J., Williamson, J., Muturi-Kioi, V., Laserson, K.F., Slutsker, L., Otieno, W., Otieno, L., Nekoye, O., Gondi, S., Otieno, A., Ogutu, B., Wasuna, R., Owira, V., Jones, D., Onyango, A.A., Njuguna, P., Chilengi, R., Akoo, P., Kerubo, C., Gitaka, J., Maingi, C., Lang, T., Olotu, A., Tsofa, B., Bejon, P., Peshu, N., Marsh, K., Owusu-Agyei, S., Asante, K.P., Osei-Kwakye K., Boahen, O., Ayamba, S., Kayan, K., Owusu-Ofori, R., Dosoo, D., Asante, I., Adjei, G., Adjei, G., Chandramohan, D., Greenwood, B., Lusingu, J., Gesase, S., Malabeja, A., Abdul, O., Kilavo, H., Mahende, C., Liheluka, E., Lemnge, M., Theander, T., Drakeley, C., Ansong, D., Agbenyega, T., Adjei, S., Boateng, H.O., Rettig, T., Bawa, J., Sylverken, J., Sambian, D., Agyekum, A., Owusu, L., Martinson, F., Hoffman, I., Mvalo, T., Kamthunzi, P., Nkomo, R., Msika, A., Jumbe, A., Chome, N., Nyakuipa, D., Chintedza, J., Ballou, W.R., Bruls, M., Cohen, J., Guerra, Y., Jongert, E., Lapierre, D., Leach, A., Lievens, M., Ofori-Anyinam, O., Vekemans, J., Carter, T., Leboulleux, D., Loucq, C., Radford, A., Savarese, B., Schellenberg, D., Sillman, M. & Vansadia, P. (2011). First results of phase 3 trial of RTS,S/AS01 malaria vaccine in African children. New England Journal of Medicine 365(20): 1863-1875.
3. Asante, K.P., Abdulla, S., Agnandji, S., Lyimo, J., Vekemans, J., Soulanoudjingar, S., Owusu, R., Shomari, M., Leach, A., Jongert, E., Salim, N., Fernandes, J.F., Dosoo, D., Chikawe, M., Issifou, S., Osei-Kwakye, K., Lievens, M., Paricek, M., Möller, T., Apanga, S., Mwangoka, G., Dubois, M.C., Madi, T., Kwara., E, Minja, R., Hounkpatin, A.B., Boahen, O., Kayan, K., Adjei, G., Chandramohan, D., Carter, T., Vansadia, P., Sillman, M., Savarese, B., Loucq, C., Lapierre, D., Greenwood, B., Cohen, J., Kremsner, P., Owusu-Agyei, S., Tanner M. & Lell, B. (2011). Safety and efficacy of the RTS, S/AS01E candidate malaria vaccine given with expandedprogramme-on-immunisation vaccines: 19 month follow-up of a randomised, open-label, phase 2 trial. Lancet Infectious Disease 11(10): 741-749.
4. Banyal, H.S. & Inselburg, J. (1985). Isolation and characterization of parasite-inhibitory Plasmodium falciparum monoclonal antibodies. American Journal Tropical Medicine and Hygiene 34: 1055-1064.
5. Barbosa, A., Naniche, D., Aponte, J.J., Manaca, M.N., Mandomando, I., Aide, P., Sacarlal, J., Renom, M., Lafuente, S., Ballou, W.R. & Alonso, P.L. (2009). Plasmodium falciparum-specific cellular immune responses after immunization with the RTS,S/AS02D candidate malaria vaccine in infants living in an area of high endemicity in Mozambique. Infectious Immunology 77(10): 4502-4509.
6. Belperron, A.A., Feltquate, D., Fox, B.A., Horii, T. & Bzik, D.J. (1999). Immune responses induced by gene gun or intramuscular injection of DNA vaccines that express immunogenic regions of the serine repeat antigen from Plasmodium falciparum. Infectious Immunology 67: 5163-5169.
7. Bharadwaj, A., Sharma, P. & Joshi, S.K. (1998). Induction of protective immune responses by immunization with linear multiepitope peptides based on conserved sequences from P. falciparum antigens. Infectious Immunology 66(7): 3232-3241.
8. Bzik, D.J., Li, W., Horii, T. & Inselburg, J. (1988). Amino acid sequence of the serine repeat antigen (SERA) of Plasmodium falciparum determined from cloned cDNA. Molecular and Biochemical Parasitology 30: 279-288.
9. de Souza, J.B., Ling, I.T., Ogun, S.A., Holder, A.A. & Playfair, J.H.L. (1996). Cytokines and antibody subclass associated with protective immunity against blood-stage malaria in mice vaccinated with the MSP1C plus a novel adjuvant. Infectious Immunology 64: 3532-3536.
10. Delplace, P., Fortier, B., Tronchin, G., Dubremetz, J.F. & Vernes, A. (1987). Localization, biosynthesis, processing and isolation of a major 126 kDa antigen of the parasitophorous vacuole of Plasmodium falciparum. Molecular Biochemical Parasitology 23: 193-201.
11. Fox, B.A. & Bzik, D.J. (1994). Analysis of stage-specific transcripts of the Plasmodium falciparum serine repeat antigen (SERA) gene and transcription from the SERA locus. Molecular Biochemical Parasitology 68: 133-144.
12. Fox, B.A., Xing-Li, P., Suzue, K., Horii, T. & Bzik, D.J. (1997). Plasmodium falciparum: an epitope within a highly conserved region of the 47-kDa amino-terminal domain of the serine repeat antigen is a target of parasite-inhibitory antibodies. Experimental Parasitology 85: 121-134.
13. Franco-Paredes, C., Rouphael, N., del Rio, C. & Santos-Preciado, J.I. (2006). Vaccination strategies to prevent tuberculosis in the new millennium: from BCG to new vaccine candidates. International Journal of Infectious Disease 10: 93-102.
14. Gardner, M.J., Hall, N., Fung, E., White, O., Berriman, M., Hyman, R.W., Carlton, J.M., Pain, A., Nelson, K.E., Bowman, S., Paulsen, I.T., James, K., Eisen, J.A., Rutherford, K., Salzberg, S.L., Craig, A., Kyes, S., Chan, M.S., Nene, V., Shallom, S.J., Suh, B., Peterson, J., Angiuoli, S., Pertea, M., Allen, J., Selengut, J., Haft, D., Mather, M.W., Vaidya, A.B., Martin, D.M., Fairlamb, A.H., Fraunholz, M.J., Roos, D.S., Ralph, S.A., McFadden, G.I., Cummings, L.M., Subramanian, G.M., Mungall, C., Venter, J.C., Carucci, D.J., Hoffman, S.L., Newbold, C., Davis, R.W., Fraser, C.M. & Barrell, B. (2002). Genome sequence of the human malaria parasite P. falciparum. Nature 419: 498-511.
15. Genton, B., D'Acremont, V., Lurati-Ruiz, F., Verhage, D., Audran, R. Hermsen, C., Wolters, L., Reymond, C., Spertini, F., Sauerwein, R. (2010). Randomized double-blind controlled Phase I/IIa trial to assess the efficacy of malaria vaccine PfCS102 to protect against challenge with P. falciparum. Vaccine 28: 6573-6580.
16. Gor, D.O., Li, A.C. & Rosenthal, P.J. (1998). Protective immune responses against protease-like antigens of the murine malaria parasite Plasmodium vinckei. Vaccine 16: 1193-1202.
17. Govan, V.A., Christensen, N.D., Berkower, C., Jacobs Jr, W.R. & Williamson, A.L. (2006). Immunization with recombinant BCG expressing the cottontail rabbit papillomavirus (CRPV) L1 gene provides protection from CRPV challenge. Vaccine 24: 2087-2093.
18. Grau, G.E. & Behr, C. (1994). T cells and malaria: is Th1 cell activation a prerequisite for pathology? Research Immunology 145: 441-454.
19. Griffin, J.F., Mackintosh, C.G. & Slobbe, L. (1999). Vaccine protocols to optimise the protective efficacy of BCG. Tuberculosis and Lung Diseases 79(3): 135-143.
20. Holder, A.A., Guevara Patino, P.A., Uthaipibull, C., Syed, S.E.H., Ling, I.T., Scott-Finnigan, T. & Blackman, M.J. (1999). Merozoite surface protein-1, immune evasion and vaccines against asexual blood stage malaria. Parassitologia 41: 409-414.
21. Horii, T., Shirai, H., Jie, L., Ishii, K.J., Palacpac, N.Q., Tougan, T., Hato, M., Ohta, N., Bobogare, A., Arakaki, N., Matsumoto, Y., Namazue, J., Ishikawa, T., Ueda, S. & Takahashi, M. (2010). Evidences of protection against blood-stage infection of Plasmodium falciparum by the novel protein vaccine SE36. Parasitology International 59: 380-386.
22. Inselburg, J., Bzik, D.J., Li, W.B., Green, K.M., Kansopon, J., Hahm, B.K., Bathurst, I.C., Barr, P.J. & Rossan, R.N. (1991). Protective immunity induced in Aotus monkeys by recombinant SERA proteins of Plasmodium falciparum. Infection and Immunity 59: 1247-1250.
23. Inselburg, J., Bathurst, I.C., Kansopon, J., Barchfeld, G.L., Barr, P.J. & Rossan, R.N. (1993a). Protective immunity induced in Aotus monkeys by recombinant SERA proteins of Plasmodium falciparum: Adjuvant effects on induction of protective immunity. Infection and Immunity 61: 2041-2047.
24. Inselburg, J., Bathurst, I.C., Kansopon, J., Barr, P.J. & Rossan, R.N. (1993b). Protective immunity induced in Aotus monkeys by recombinant SERA proteins of Plasmodium falciparum: Futher studies using SERA 1 and MF75.2 adjuvant. Infection and Immunity 61: 2048-2052.
25. Iriemenam, N.C., Khirelsied, A.H., Nasr, A., ElGhazali, G., Giha, H.A., Elhassan A-Elgadir, T.M., Agab-Aldour, A.A., Montgomery, S.M., Anders, R.S., Theisenk, M., Troye-Blomberg, M., Elbashirc, M.I. & Berzins, K. (2009). Antibody responses to a panel of Plasmodium falciparum malaria blood-stage antigens in relation to clinical disease outcome in Sudan. Vaccine 27: 62-71.
26. Jason, J., Archibald, L.K., Nwanyanwu, O.C., Bell, M., Buchanan, I. & Larned, J. (2001). Cytokines and malaria parasitemia. Clinical Immunology 100: 208-218.
27. Kaufmann, S.H. & Andersen, P. (1998). Immunity to mycobacteria with emphasis on tuberculosis: implications for rational design of an effective tuberculosis vaccine. Chemical Immunology 70: 21-59.
28. Kester, K.E., Cummings, J.F., Ockenhouse, C.F., Nielsen, R., Hall, B.T., Gordon, D.M., Schwenk, R.J., Krzych, U., Holland, C.A., Richmond, G., Dowler, M.G., Williams, J., Wirtz, R.A., Tornieporth, N., Vigneron, L., Delchambre, M., Demoitie, M.A., Ballou, W.R., Cohen, J., Heppner, D.G. Jr; RTS, S Malaria Vaccine Evaluation Group. (2008). Phase 2a trial of 0, 1, and 3 month and 0, 7, and 28 day immunization schedules of malaria vaccine RTS,S/ AS02 in malaria-naive adults at the Walter Reed Army Institute of Research. Vaccine 26: 2191-2202.
29. Leach, A., Vekemans, J., Lievens, M., Ofori-Anyinam, O., Cahill, C., Owusu-Agyei, S., Abdulla, S., Macete, E., Njuguna, P., Savarese, B., Loucq, C. & Ballou, W.R. (2011). Design of a phase III multicenter trial to evaluate the efficacy of the RTS,S/ AS01 malaria vaccine in children across diverse transmission settings in Africa. Malaria Journal 10: 224.
30. Leung, N.J., Aldovini, A., Young, R., Jarvis, M.A., Smith, J.M., Meyer, D., Anderson, D.E., Carlos, M.P., Gardner, M.B. & Torres, J.V. (2000). The kinetics of specific immune responses in rhesus monkeys inoculated with live recombinant BCG expressing SIV Gag, Pol, Env and Nef proteins. Virology 268: 94-103.
31. Lusingu, J., Olotu, A., Leach, A., Lievens, M., Vekemans, J., Olivier, A., Benns, S., Olomi, R., Msham, S., Lang, T., Gould, J., Hallez, K., Guerra, Y., Njuguna, P., Awuondo, K.O., Malabeja, A., Abdul, O., Gesase, S, Dekker, D., Malle, L., Ismael, S., Mturi, N., Drakeley, C.J., Savarese, B., Villafana, T., Ballou, W.R., Cohen, J., Riley, E.M., Lemnge, M.M., Marsh, K., Bejon, P. & von Seidlein, L. (2011). Safety of the malaria vaccine candidate, RTS,S/AS01E in 5 to 17 month old Kenyan and Tanzanian children. PLoS One 5(11): e14090.
32. Malaysia Health Ministry. (2004). Status of malaria control in Malaysia. Disease Control Division.
33. Matsumoto, S., Yukitake, H., Kanbara, H. & Yamada, T. (1998). Recombinant M. bovis BCG secreting merozoite surface protein 1(MSP-1) induces protection against rodent malaria parasite infection depending on MSP-1 stimulated interferon-γ and parasite-specific antibodies. Journal Experimental Medicine 188: 845-854.
34. Matsumoto, S., Yukitake, H., Kanbara, H., Yamada, H., Kitamura, A. & Yamada, T. (2001). M. bovis bacille Calmette-Guerin induces protective immunity against infection by P. yoelii at blood-stage depending on shifting immunity toward Th1 type and inducing protective IgG2a after the parasite infection. Vaccine 19: 779-787.
35. Mederle, I., Bourguin, I., Ensergueix, D., Badell, E., Moniz-Peireira, J., Gicquel, B. & Winter, N. (2002). Plasmidic versus insertional cloning of heterologous genes in M. bovis BCG: impact on in vivo antigen persistence and immune responses. Infection and Immunity 70: 303-314.
36. Nascimento, I.P., Waldely, O.D., Mazzantini, R.P., Miyaji, E.N., Gamberini, M., Quintilio, W., Gebara, V.C., Cardoso, D.F., Ho, P.L., Raw, I., Winter, N., Gicquel, B., Rappuoli, R. & Leite, L.C.C. (2000). Recombinant M. bovis BCG expressing pertussis toxin subunit S1 induces protection against an intracerebral challenge with live Bordetella pertussis in mice. Infection and Immunity 68: 4877-4883.
37. Norazmi, M.N., Zainuddin, Z.F., Suppian, R. & Dale, J.W. (1999). The use of assembly PCR for cloning of a malarial epitope into M. smegmatis - importance of overcoming codon bias. Biotechnology Technique 13: 485-489.
38. Nurul, A.A., Rapeah, S. & Norazmi, M.N. (2010). Plasmodium falciparum 19 kDa of merozoite surface protein-1 (MSP-119) expressed in Mycobacterium bovis bacille Calmette Guerin (BCG) is reactive with an inhibitory but not a blocking monoclonal antibody. Tropical Biomedicine 27(1): 60-67.
39. Nurul, A.A. & Norazmi, M.N. (2011). Immunogenicity and in vitro protective efficacy of recombinant Mycobacterium bovis bacille Calmette Guerin (rBCG) expressing the 19 kDa merozoite surface protein-1 (MSP-1,9) antigen of Plasmodium falciparum. Parasitology Research 108: 887-897.
40. O'Donnell, M.A., Aldovini, A. & Duba, R. (1994). Recombinant Mycobacterium bovis BCG secreting functional interleukin-2 enhances gamma interferon production by splenocytes. Infection and Immunity 62: 2508-2514.
41. Okech, B.A., Nalunkuma, A., Okello, D., Pang, X.L., Suzue, K., Li, J., Horii, T. & Egwang, T.G. (2001). Natural human immunoglobulin G subclass responses to Plasmodium falciparum serine repeat antigen in Uganda. American Journal of Tropical Medicine and Hygiene 65: 912-917.
42. Okech, B.A., Mujuzi, G., Ogwal, A., Shirai, H., Horii, T. & Egwang, T.G. (2006). High titers of IgG antibodies against Plasmodium falciparum serine repeat antigen 5 (SERA5) are associated with protection against severe malaria in Ugandan children. American Journal of Tropical Medicine and Hygiene 74: 191-197.
43. Pang, X.L. & Horii, T. (1998). Complement-mediated killing of Plasmodium falciparum erythrocytic schizont with antibodies to the recombinant serine repeat antigen (SERA). Vaccine 16: 1299-1305.
44. Pang, X.L., Mitamura, T. & Horii, T. (1999). Antibodies reactive with the N-terminal domain of Plasmodium falciparum serine repeat antigen inhibit cell proliferation by agglutinating merozoites and schizonts. Infection and Immunity 67: 1821-1827.
45. Perkins, M.E. & Ziefer, A. (1994). Preferential binding of Plasmodium falciparum SERA and rhoptry proteins to erythrocyte membrane inner leaflet phospholipids. Infection and Immunity 62: 1207-1212.
46. Plebanski, M. & Hill, A.V.S. (2000). The immunology of malaria. Current Opinion in Immunology 12: 437-441.
47. Puentes, A., Garcia, J., Vera, R., Lopez, Q.R., Urquiza, M., Vanegas, M., Salazar, L.M. & Patarroyo, M.E. (2000). Serine repeat antigen peptides which bind specifically to red blood cells. Parasitology International 49: 105-117.
48. Rezende, C.A.F., De Moraes, M.T.B., De Souza Matos, D.C., Mcintoch, D. & Garcia Armoa, G.R. (2005) Humoral response and genetic stability of recombinant BCG expressing hepatitis B surface antigens. Journal of Virological Methods 125: 1-9.
49. Sakai, T., Horii, T., Hisaeda, H., Zhang, M., Ishii, K., Nakano, Y., Maekawa, Y., Izumi, K., Nitta, Y., Miyazaki, J. & Himeno, K. (1999). DNA immunization with Plasmodium falciparum serine repeat antigen: regulation of humoral immune response by coinoculation of cytokine expression plasmid. Parasitology International 48: 27-33.
50. Smith, E.C. & Taylor-Robinson, A.W. (2003). Parasite-specific immunoglobulin isotypes during lethal and non-lethal murine malaria infections. Parasitology Research 89: 26-33.
51. + T cells producing IFN-γ. Journal of Immunology 171(12): 6961-6967.
52. Taylor-Robinson, A.W. (1995). Regulation of immunity to malaria: valuable lessons learned from murine models. Parasitology Today 11: 334-342.
53. Torre, D., Speranza, F., Giola, M., Matteelli, A., Tambini, R. & Biondi, G. (2002). Role of Th1 and Th2 cytokines in immune response to uncomplicated Plasmodium falciparum malaria. Clinical and Diagnostic Lab Immunology 9: 348-351.
54. Troye-Blomberg, M., Berzins, K. & Perlmann, P. (1994). T-cell control of immunity to the asexual blood stages of the malaria parasite. Critical Review in Immunology 14: 131-155.
55. Wang, R., Epstein, J., Charoenvit, Y., Baraceros, F.M., Rahardjo, N., Gay, T., Banania, J.G., Chattopadhyay, R., de la Vega, P., Richie, T.L., Tornieporth, N., Doolan, D.L., Kester, K.E., Heppner, D.G., Norman, J., Carucci, D.J., Cohen, J.D. & Hoffman, S.L. (2004). Induction in humans of CD8+ and CD4+ T cell and antibody responses by sequential immunization with malaria DNA and recombinant protein. Journal of Immunology 172: 5561-5569.
56. Wang, R., Richie, T.L., Baraceros, M.F., Rahardjo, N., Gay, T., Banania, J.G., Charoenvit, Y., Epstein, J.E., Luke, T., Freilich, D.A., Norman, J. & Hoffman, S.L. (2005). Boosting of DNA vaccine-elicited gamma interferon responses in humans by exposure to malaria parasites. Infection and Immunity 73: 2863-2872.
57. Weber, J.L., Lyon, J.A. & Camus, D. (1987). Blood stage antigen genes of Plasmodium falciparum. In: Agabian, N., Goodman, H. and Nogueira, N. Molecular Strategies Of Parasite Invasion. New York: Alan R. Liss, pg. 379-388.
58. Winkler, S., Willheim, M., Baier, K., Schmid, D., Aichelburg, A., Graninger, W. & Kremsner, P.G. (1998). Reciprocal regulation of Th1- and Th2-cytokineproducing T cells during clearance of parasitemia in P. falciparum malaria. Infection and Immunity 66: 6040-6044.
59. Young, S. (2002). Manipulation of immune responses to M. bovis by vaccination with IL-2- and IL-8-secreting recombinant BCG. Immunology and Cell Biology 80: 209-215.
60. Zheng, C., Xie, P. & Chen, Y. (2002a). Recombinant Mycobacterium bovis BCG producing the circumsporozoite protein of Plasmodium falciparum FCC/HN strain inducer strong immune responses in Balb/c mice. Parasitology International 51: 1-7.
61. Zheng, C., Xie, P. & Chen, Y. (2002b). Immune response induced by recombinant BCG expressing merozoite surface antigen 2 from Plasmodium falciparum. Vaccine 20: 914-919.