{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,7,31]],"date-time":"2026-07-31T02:34:54Z","timestamp":1785465294591,"version":"3.56.0"},"reference-count":55,"publisher":"MDPI AG","issue":"12","license":[{"start":{"date-parts":[[2024,6,9]],"date-time":"2024-06-09T00:00:00Z","timestamp":1717891200000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Animals"],"abstract":"<jats:p>Streptococcosis caused by Streptococcus agalactiae (S. agalactiae) is a major bacterial disease affecting the production of Nile tilapia (Oreochromis niloticus L.), causing significant economic losses due to mortality in the growing phase. Vaccination is the most effective method for preventing streptococcosis on Nile tilapia farms. In Brazil, the major tilapia-producing regions have long production cycles (6\u201310 months) and harvest tilapias weighing over 900 g for fillet production. Thus, data on the duration of the humoral immune response and protection in farmed tilapia have not been reported or are poorly described. Furthermore, the efficiency of serological testing for the long-term monitoring of immune responses induced by vaccination against S. agalactiae has never been addressed. This study evaluated the duration of protection and humoral immune response induced in Nile tilapia vaccinated against S. agalactiae until 300 days post-vaccination (dpv). The immunization trial was composed of two groups: vaccinated (Vac), vaccinated intraperitoneally with a commercial vaccine, and unvaccinated (NonVac) group, injected fish with sterile saline solution. At 15, 30, 150, 180, 210, and 300 dpv, blood sampling was conducted to detect anti-S. agalactiae IgM antibodies using indirect Enzyme-Linked Immunosorbent Assay (ELISA), and the fish were challenged with pathogenic S. agalactiae to determine the duration of vaccine protection through relative percentage survival (RPS). Spearman\u2019s rank correlation was performed between the ELISA optical density (OD) of vaccinated tilapia and the duration of vaccine protection (RPS). The mean cumulative mortality in NonVac and Vac groups ranged from 65 to 90% and less than 35%, respectively. The average RPS was 71, 93, 94, 70, 86, and 67% at 15, 30, 150, 180, 210, and 300 dpv, respectively. RPS revealed that the vaccine provided protection from 15 to 300 dpv. The specific anti-S. agalactiae IgM antibody levels were significantly higher in the Vac group than that non-Vac group up to 180 dpv. The vaccinated fish exhibited significant protection for up to 10 months after vaccination. There was a positive correlation between the antibody response and RPS. This study revealed that a single dose of commercial vaccine administered to Nile tilapia can confer long-term protection against S.\u00a0agalactiae and that indirect ELISA can monitor the duration of the humoral immune response for up to six months following vaccination. Finally, vaccine protection over six months can be associated with other components of the fish immune system beyond the humoral immune response by IgM antibodies.<\/jats:p>","DOI":"10.3390\/ani14121744","type":"journal-article","created":{"date-parts":[[2024,6,10]],"date-time":"2024-06-10T08:49:03Z","timestamp":1718009343000},"page":"1744","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":16,"title":["Duration of Protection and Humoral Immune Response in Nile Tilapia (Oreochromis niloticus L.) Vaccinated against Streptococcus agalactiae"],"prefix":"10.3390","volume":"14","author":[{"ORCID":"https:\/\/orcid.org\/0000-0003-0762-7407","authenticated-orcid":false,"given":"Guilherme Alves de","family":"Queir\u00f3z","sequence":"first","affiliation":[{"name":"Department of Preventive Veterinary Medicine, Veterinary School, Federal University of Minas Gerais, Belo Horizonte 31270-901, MG, Brazil"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Tarc\u00edsio Martins Fran\u00e7a e","family":"Silva","sequence":"additional","affiliation":[{"name":"Department of Preventive Veterinary Medicine, Veterinary School, Federal University of Minas Gerais, Belo Horizonte 31270-901, MG, Brazil"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-0001-3920","authenticated-orcid":false,"given":"Carlos Augusto Gomes","family":"Leal","sequence":"additional","affiliation":[{"name":"Department of Preventive Veterinary Medicine, Veterinary School, Federal University of Minas Gerais, Belo Horizonte 31270-901, MG, Brazil"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2024,6,9]]},"reference":[{"key":"ref_1","unstructured":"FAO (2022). Towards Blue Transformation. State World Fish. Aquacult, Food and Agriculture Organization."},{"key":"ref_2","unstructured":"IBGE (2023, November 06). Produ\u00e7\u00e3o da Pecu\u00e1ria Municipal 2022. Rio de Janeiro, Available online: https:\/\/biblioteca.ibge.gov.br\/index.php\/bibliotecacatalogo?view=detalhes&id=784."},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"180","DOI":"10.1016\/j.vetmic.2008.10.016","article-title":"Aspects of the natural history and virulence of S. agalactiae infection in Nile tilapia","volume":"136","author":"Mian","year":"2009","journal-title":"Vet. Microbiol."},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"100","DOI":"10.1016\/j.aquaculture.2018.08.023","article-title":"Seasonal dynamics of bacterial pathogens of Nile tilapia farmed in a Brazilian reservoir","volume":"498","author":"Delphino","year":"2019","journal-title":"Aquaculture"},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"51","DOI":"10.1016\/j.aquaculture.2018.04.037","article-title":"Recurrent Streptoccoccus agalactiae infection in Nile tilapia (Oreochromis niloticus) treated with florfenicol","volume":"493","author":"Oliveira","year":"2018","journal-title":"Aquaculture"},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"568","DOI":"10.1111\/raq.12741","article-title":"Antimicrobial resistance in aquaculture: A global analysis of literature and national action plans","volume":"15","author":"Caputo","year":"2023","journal-title":"Rev. Aquac."},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"131","DOI":"10.1016\/j.prevetmed.2018.12.003","article-title":"Economic appraisal of vaccination against Streptoccocus agalactiae in Nile tilapia farms in Brazil","volume":"162","author":"Delphino","year":"2019","journal-title":"Prev. Vet. Med."},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"162","DOI":"10.1002\/aah.10132","article-title":"Prevention and control of streptococcosis in tilapia culture: A systematic review","volume":"33","author":"Maulu","year":"2021","journal-title":"J. Aquat. Anim. Health"},{"key":"ref_9","doi-asserted-by":"crossref","unstructured":"Ma, J., Bruce, T.J., Jones, E.M., and Cain, K.D. (2019). A review of fish vaccine development strategies: Conventional methods and modern biotechnological approaches. Microorganisms, 7.","DOI":"10.3390\/microorganisms7110569"},{"key":"ref_10","unstructured":"Cai, J., Quagrainie, K., and Hishamunda, N. (2017). Social and Economic Performance of Tilapia Farming in Africa, Food and Agriculture Organization. Available online: https:\/\/www.fao.org\/3\/i7258en\/I7258EN.pdf."},{"key":"ref_11","unstructured":"Liu, J., Li, Z., Li, X., and Wang, Y. (2013). On-Farm Feed Management Practices for Nile Tilapia in Southern China, Food and Agriculture Organization. FAO Fisheries and Aquaculture Technical Paper."},{"key":"ref_12","unstructured":"Barroso, R., Mu\u00f1oz, A.E., and Cai, J. (2019). Social and economic performance of tilapia farming in Brazil. FAO Fisheries and Aquaculture Circular no 1181, Food and Agriculture Organization."},{"key":"ref_13","unstructured":"PeixeBR (2023, July 20). Anu\u00e1rio Brasileiro da Piscicultura PEIXE. Br. S\u00e3o Paulo, Brazil. Available online: https:\/\/www.peixebr.com.br\/anuario\/."},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"163","DOI":"10.3354\/dao03084","article-title":"Development of Streptococcus agalactiae vaccines for tilapia","volume":"122","author":"Liu","year":"2016","journal-title":"Dis. Aquat. Organ."},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"175","DOI":"10.1016\/S0165-2427(96)05738-8","article-title":"Development and efficacy of a vaccine against Streptococcus iniae infection in farmed rainbow trout","volume":"56","author":"Eldar","year":"1997","journal-title":"Vet. Immunol. Immunopathol."},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"129","DOI":"10.3354\/dao066129","article-title":"Duration of protective antibodies and correlation with survival in Nile tilapia Oreochromis niloticus following Streptococcus agalactiae vaccination","volume":"66","author":"Pasnik","year":"2005","journal-title":"Dis. Aquat. Organ."},{"key":"ref_17","unstructured":"Brasil, S. (2023, January 15). Tilapicultura Cresce com Sanidade e Ado\u00e7\u00e3o de Novas Tecnologias. Revista Seafood Brasil. S\u00e3o Paulo, Brazil. Available online: http:\/\/seafoodbrasil.com.br\/tilapicultura-cresce-com-sanidade-e-adocao-de-novas-784tecnologias."},{"key":"ref_18","unstructured":"Wendover, N., Aguirre, M., Zanolo, R., Cericato, L., and Wardle, R. (2023, July 20). Streptococcus in tilapia: Implications for vaccine development and field experiences from Asia. In Bacterial Disease in Warmwater Fish: New Strategies for Sustainable Control; MSD Animal Health Global Aquaculture Advocate (Ed.), New Hampshire, USA. Available online: https:\/\/thefishsite.com\/articles\/streptococcus-in-tilapia-implications-for-vaccine-development-field-experiences-from-asia."},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"1","DOI":"10.35172\/rvz.2023.v30.998","article-title":"An\u00e1lise de \u00e2ngulos e pontos para vacina\u00e7\u00e3o de til\u00e1pias-do-Nilo","volume":"30","author":"Rocha","year":"2023","journal-title":"Vet. Zootec."},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"445","DOI":"10.1016\/j.fsi.2017.05.041","article-title":"Comprehensive evaluation of immunomodulation by moderate hypoxia in S. agalactiae vaccinated Nile tilapia","volume":"66","author":"Gallage","year":"2017","journal-title":"Fish Shellfish Immunol."},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"734943","DOI":"10.1016\/j.aquaculture.2020.734943","article-title":"Influence of temperature on the vaccine efficacy against Streptococcus agalactiae in Nile tilapia (Oreochromis niloticus)","volume":"521","author":"Wang","year":"2020","journal-title":"Aquaculture"},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"489","DOI":"10.1016\/j.cimid.2013.05.002","article-title":"Evaluation of protection conferred by a Salmonella Typhimurium inactivated vaccine in Salmonella-infected finishing pig farms","volume":"36","author":"Arguello","year":"2013","journal-title":"Comp. Immunol. Microbiol. Infect. Dis."},{"key":"ref_23","first-page":"2","article-title":"Infectious bronchitis virus (Gammacoronavirus) in poultry farming: Vaccination, immune response and measures for mitigation","volume":"8","author":"Bhuiyan","year":"2021","journal-title":"Vet. Sci."},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"75","DOI":"10.20506\/rst.40.1.3209","article-title":"A review of diagnostic tests recommended by the World Organisation for Animal Health Manual of Diagnostic Tests and vaccines for Terrestrial Animals","volume":"40","author":"Cullinane","year":"2021","journal-title":"OIE Rev. Sci. Tech."},{"key":"ref_25","doi-asserted-by":"crossref","first-page":"1","DOI":"10.1080\/08997659.2016.1244577","article-title":"Serology in finfish for diagnosis, surveillance, and research: A systematic review","volume":"29","author":"Jaramillo","year":"2017","journal-title":"J. Aquat. Anim. Health."},{"key":"ref_26","doi-asserted-by":"crossref","first-page":"817","DOI":"10.1007\/s10499-019-00372-8","article-title":"Streptococcosis in Oreochromis sp.: Is feed-based biofilm vaccine of Streptococcus agalactiae effective?","volume":"27","author":"Kahieshesfandiari","year":"2019","journal-title":"Aquac. Int."},{"key":"ref_27","doi-asserted-by":"crossref","first-page":"229","DOI":"10.1016\/j.fsi.2022.03.007","article-title":"Pre-treatment of Nile tilapia (Oreochromis niloticus) with ozone nanobubbles improve efficacy of heat-killed Streptococcus agalactiae immersion vaccine","volume":"123","author":"Linh","year":"2022","journal-title":"Fish Shellfish Immunol."},{"key":"ref_28","doi-asserted-by":"crossref","first-page":"405","DOI":"10.1016\/j.fsi.2020.07.024","article-title":"Characterization of novel antigenic vaccine candidates for Nile tilapia (Oreochromis niloticus) against Streptococcus agalactiae infection","volume":"105","author":"Ma","year":"2020","journal-title":"Fish Shellfish Immunol."},{"key":"ref_29","doi-asserted-by":"crossref","first-page":"1513","DOI":"10.1111\/are.14499","article-title":"Maternal immunity of tilapia broodstock vaccinated with polyvalent vaccine and resistance of their offspring against Streptococcus agalactiae","volume":"51","author":"Nurani","year":"2020","journal-title":"Aquac Res."},{"key":"ref_30","doi-asserted-by":"crossref","first-page":"735484","DOI":"10.1016\/j.aquaculture.2020.735484","article-title":"A comparison of novel inactivation methods for production of a vaccine against Streptococcus agalactiae in Nile tilapia Oreochromis niloticus","volume":"528","year":"2020","journal-title":"Aquaculture"},{"key":"ref_31","doi-asserted-by":"crossref","unstructured":"Ross, L.G., and Ross, B. (2008). Anaesthetic and Sedative Techniques for Aquatic Animals, Blackwell Publishing. [3rd ed.].","DOI":"10.1002\/9781444302264"},{"key":"ref_32","doi-asserted-by":"crossref","first-page":"1985","DOI":"10.1128\/JCM.00159-07","article-title":"Multiplex PCR assay for rapid and accurate capsular typing of group B streptococci","volume":"45","author":"Poyart","year":"2007","journal-title":"J. Clin. Microbiol."},{"key":"ref_33","first-page":"493","article-title":"A simple method of estimating fifty per cent endpoints","volume":"27","author":"Reed","year":"1938","journal-title":"Am. J. Hyg."},{"key":"ref_34","first-page":"732","article-title":"The estimation of the bactericidal power of the blood","volume":"38","author":"Miles","year":"1938","journal-title":"J. Hyg."},{"key":"ref_35","first-page":"447","article-title":"Potency testing of fish vaccines","volume":"49","author":"Amend","year":"1982","journal-title":"Dev. Biol. Stand."},{"key":"ref_36","doi-asserted-by":"crossref","first-page":"657","DOI":"10.1007\/s10499-009-9287-x","article-title":"Oral and parenteral vaccines against Flavobacterium columnare: Evaluation of humoral immune response by ELISA and in vivo efficiency in Nile tilapia (Oreochromis niloticus)","volume":"18","author":"Leal","year":"2010","journal-title":"Aquacult. Int."},{"key":"ref_37","doi-asserted-by":"crossref","first-page":"86","DOI":"10.1016\/j.biologicals.2013.11.007","article-title":"Comparison of a serological potency assay for furunculosis vaccines (Aeromonas salmonicida subsp. salmonicida) to intraperitoneal challenge in Atlantic salmon (Salmo salar L.)","volume":"42","author":"Romstad","year":"2014","journal-title":"Biologicals"},{"key":"ref_38","doi-asserted-by":"crossref","first-page":"6088","DOI":"10.1016\/j.vaccine.2012.07.044","article-title":"Screening vaccine candidate strains against Streptococcus agalactiae of tilapia based on PFGE genotype","volume":"30","author":"Chen","year":"2012","journal-title":"Vaccine"},{"key":"ref_39","doi-asserted-by":"crossref","first-page":"955","DOI":"10.1016\/j.fsi.2015.06.014","article-title":"Development of live attenuated Streptococcus agalactiae vaccine for tilapia via continuous passage in vitro","volume":"45","author":"Li","year":"2015","journal-title":"Fish Shellfish Immunol."},{"key":"ref_40","doi-asserted-by":"crossref","first-page":"1740","DOI":"10.1016\/j.fsi.2013.02.029","article-title":"Adjuvants and immunostimulants in fish vaccines: Current knowledge and future perspectives","volume":"35","author":"Tafalla","year":"2013","journal-title":"Fish Shellfish Immunol."},{"key":"ref_41","doi-asserted-by":"crossref","first-page":"19","DOI":"10.1016\/j.fsi.2021.06.014","article-title":"Immune response and protective efficacy of two new adjuvants, MontanideTM ISA 763B VG and MontanideTM GEL02, administered with a Streptococcus agalactiae ghost vaccine in Nile tilapia (Oreochromis niloticus)","volume":"116","author":"Wangkaghart","year":"2021","journal-title":"Fish Shellfish Immunol."},{"key":"ref_42","doi-asserted-by":"crossref","first-page":"132","DOI":"10.1016\/j.fsi.2018.03.060","article-title":"Correlates of protective immunity for fish vaccines","volume":"85","author":"Evensen","year":"2019","journal-title":"Fish Shellfish Immunol."},{"key":"ref_43","doi-asserted-by":"crossref","first-page":"139","DOI":"10.1006\/fsim.1998.0183","article-title":"Duration of protective antibodies, and the correlation with protection in Atlantic salmon (Salmo salar L.), following vaccination with an Aeromonas salmonicida vaccine containing iron-regulated outer membrane proteins and secretory polysaccharide","volume":"9","author":"Bricknell","year":"1999","journal-title":"Fish Shellfish Immunol."},{"key":"ref_44","doi-asserted-by":"crossref","unstructured":"Villumsen, K.R., Dalsgaard, I., Holten-Andersen, L., and Raida, M.K. (2012). Potential Role of Specific Antibodies as Important Vaccine Induced Protective Mechanism against Aeromonas salmonicida in Rainbow Trout. PLoS ONE., 7.","DOI":"10.1371\/annotation\/48f605ab-75a9-4f93-9b4a-ab4358cd15d6"},{"key":"ref_45","doi-asserted-by":"crossref","unstructured":"Raida, M.K., Nyl\u00e9n, J., Holten-Andersen, L., and Buchmann, K. (2011). Association between plasma antibody response and protection in rainbow trout Oncorhynchus mykiss immersion vaccinated against Yersinia ruckeri. PLoS ONE., 6.","DOI":"10.1371\/journal.pone.0018832"},{"key":"ref_46","doi-asserted-by":"crossref","first-page":"365","DOI":"10.1016\/j.fsi.2006.01.001","article-title":"Passive immunization of Nile tilapia (Oreochromis niloticus) provides significant protection against Streptococcus agalactiae","volume":"21","author":"Pasnik","year":"2006","journal-title":"Fish Shellfish Immunol."},{"key":"ref_47","doi-asserted-by":"crossref","first-page":"184","DOI":"10.1016\/j.dci.2013.08.008","article-title":"Acquired immunity and vaccination against infectious pancreatic necrosis virus of salmon","volume":"43","author":"Mutoloki","year":"2014","journal-title":"Dev. Comp. Immunol."},{"key":"ref_48","doi-asserted-by":"crossref","first-page":"214","DOI":"10.1016\/j.aquaculture.2019.03.058","article-title":"Expression and characterization of Nile tilapia (Oreochromis niloticus) secretory and membrane-bound IgM in response to bacterial infection","volume":"508","author":"Yin","year":"2019","journal-title":"Aquaculture"},{"key":"ref_49","doi-asserted-by":"crossref","unstructured":"Yu, Y.Y., Kong, W., Yin, Y.X., Dong, F., Huang, Z.Y., Yin, G.M., Dong, S., Salinas, I., Zhang, Y.A., and Xu, Z. (2018). Mucosal immunoglobulins protect the olfactory organ of teleost fish against parasitic infection. PLOS Pathog., 14.","DOI":"10.1101\/380691"},{"key":"ref_50","doi-asserted-by":"crossref","first-page":"65","DOI":"10.1007\/s00251-020-01195-1","article-title":"Immunoglobulins in teleosts","volume":"73","author":"Bilal","year":"2021","journal-title":"Immunogenetics"},{"key":"ref_51","doi-asserted-by":"crossref","unstructured":"Beck, B.H., and Peatman, E. (2015). Fish mucosal immunity: Intestine. Mucosal Health in Aquaculture, Elsevier Inc.","DOI":"10.1016\/B978-0-12-417186-2.00013-3"},{"key":"ref_52","doi-asserted-by":"crossref","first-page":"124","DOI":"10.1016\/j.dci.2018.07.013","article-title":"Discovery of immunoglobulin T in Nile tilapia (Oreochromis niloticus): A potential molecular marker to understand mucosal immunity in this species","volume":"88","author":"Acosta","year":"2018","journal-title":"Dev. Comp. Immunol."},{"key":"ref_53","doi-asserted-by":"crossref","unstructured":"Wang, B., Wang, P., Wu, Z.H., Lu, Y.S., Wang, Z.L., and Jian, J.C. (2016). Molecular cloning and expression analysis of IgD in Nile tilapia (Oreochromis niloticus) in response to Streptococcus agalactiae stimulus. Int. J. Mol. Sci., 17.","DOI":"10.3390\/ijms17030348"},{"key":"ref_54","doi-asserted-by":"crossref","unstructured":"Adams, A. (2016). Methods for measuring efficacy, safety and potency of fish vaccines. Fish Vaccines, Springer.","DOI":"10.1007\/978-3-0348-0980-1"},{"key":"ref_55","doi-asserted-by":"crossref","first-page":"2097","DOI":"10.1111\/jfd.13523","article-title":"Efficacy of heat-killed and formalin-killed vaccines against Tilapia tilapinevirus in juvenile Nile tilapia (Oreochromis niloticus)","volume":"44","author":"Mai","year":"2021","journal-title":"J. Fish Dis."}],"container-title":["Animals"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/2076-2615\/14\/12\/1744\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,10]],"date-time":"2025-10-10T14:56:04Z","timestamp":1760108164000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/2076-2615\/14\/12\/1744"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2024,6,9]]},"references-count":55,"journal-issue":{"issue":"12","published-online":{"date-parts":[[2024,6]]}},"alternative-id":["ani14121744"],"URL":"https:\/\/doi.org\/10.3390\/ani14121744","relation":{},"ISSN":["2076-2615"],"issn-type":[{"value":"2076-2615","type":"electronic"}],"subject":[],"published":{"date-parts":[[2024,6,9]]}}}