Streptococcus agalactiae serotype 1a (ST7, CC1) is an important pathogen in Latin American tilapia aquaculture, causing significant economic losses and challenges in the context of current climatic changes. The aim of the study was to evaluate the efficacy of vaccination in tilapia farmed under field conditions in Latin America against Streptococcus agalactiae serotype 1a. This independent research involved the monitoring of vaccinated populations using different commercial bacterin-based and autovaccine vaccines in several farms and different production systems (net cages, ponds, IPRS) to evaluate health outcomes, growth rates and mortality rates using a specific mortality rate ranked by cause of "Streptococcosis". Results indicate that vaccinated tilapia showed relative efficacy in reducing streptococcal mortality, delayed time to first outbreak (approximately 30 days), and short-term productive effect under actual rearing conditions. While the vaccine used, considered as an individual measure, is important, it is imperative to define and implement a vaccination strategy (beyond a single application) to keep fish protected throughout most of the production cycle. The study concludes that vaccination contributes to the control of Streptococcus agalactiae 1a in tilapia farming, which is a step forward, but more and better collaborative work is needed in the industry to better understand the immunological response of tilapia in culture and to design the best vaccination strategy to control the disease under field conditions.