Animal Tuberculosis
Lloyd N. Friedman, Martin Dedicoat, Peter D. O. Davies in Clinical Tuberculosis, 2020
Used alone, the BCG vaccine does not provide cost-effective or useful protection against infection of M. bovis in cattle. The current BCG vaccine does not have a high enough efficacy to provide full protection against tuberculosis, and is currently administered to cattle to provide a “Ring Vaccination” initiative in exposed herds where a breakout of TB infection has occurred. The same concern with this vaccine exists in cattle as in humans, as cattle that have received the BCG vaccine may offer a false-positive reaction to the tuberculin SICCT and therefore cattle infected with tuberculosis, and those which have been vaccinated, cannot be differentiated. The rational development of an effective vaccine for cattle involves the development of the optimal combination of M. bovis antigens that are required for protective immunity. Diagnostic tests based on antigens not incorporated into the vaccine would allow differentiation of the immune response generated by either vaccination or infection.
Control of Tuberculosis in High-Prevalence Countries
Peter D O Davies, Stephen B Gordon, Geraint Davies in Clinical Tuberculosis, 2014
The only vaccine to prevent TB was developed 86 years ago by Albert Calmette and Camilla Guerin. This vaccine is a live attenuated form of Mycobacterium bovis. The vaccine has been extensively used worldwide, and 100 million doses are given to children each year. It has reduced mortality by about 90% in vaccinated children [108]. BCG vaccine protects children from severe forms of TB – haematogenous, miliary or disseminated TB. In 2002 alone, BCG prevented an estimated 30,000 cases of meningeal TB during infancy [109,110]. But, the protective effect of BCG vaccine diminishes with 10–15 years, and a booster dose does not confer any additional benefit [111]. Thus, it is powerless against occurrence of pulmonary TB in children or adults. Although this fact is known to all, BCG vaccine is included in the immunisation programmes for children in nearly all the 22 HBCs.
Malaria, tuberculosis and other infectious diseases
Théodore H MacDonald, Noël A Kinsella, John A Gibson in The Global Human Right to Health, 2018
European civilisation lived with tuberculosis for centuries, and indeed in many instances Europeans spread the disease to areas of the less developed world that had never had it before. In Victorian times it was commonplace, especially among the poor, in large cities such as London, Paris and New York. Often referred to as ‘consumption’, it was long after the discovery of the bacterium responsible (Mycobacterium tuberculosis) that medical scientists in the developed world finally worked out how to treat it and prevent it. Starting in the 1930s and 1940s, most of the developed-world nations undertook the use of mass X-ray campaigns in schools, etc., and the use of BCG vaccination and the Mantoux test were hugely effective in dramatically reducing the incidence of TB in the developed world. The BCG vaccine is a preparation of attenuated Mycobacterium bacilli that, once injected into a healthy person, causes immunity to further infection. The letters BCG stand for ‘bacillus of Chalmette and Guérin’, referring to the two discoverers of the vaccine. The Mantoux test is a skin test which shows whether the person is already naturally immune or whether they need the BCG vaccination for protection.
COVID-19 pandemic: SARS-CoV-2 specific vaccines and challenges, protection via BCG trained immunity, and clinical trials
Published in Expert Review of Vaccines, 2021
Wenping Gong, Ashok Aspatwar, Shuyong Wang, Seppo Parkkila, Xueqiong Wu
The BCG vaccine is a live attenuated vaccine that has been used for more than 100 years as a prophylactic agent against tuberculosis (TB). The BCG vaccine is in the essential list of the World Health Organization (WHO) and is used in childhood immunization programs in many countries. Currently, there is no direct evidence to support the use of the BCG vaccine for the prevention of coronavirus infections [31]. However, the available data show that the BCG vaccine provides nonspecific protection against lethal infections that are not related to the vaccine’s target pathogen by inducing trained nonspecific innate immune cells to improve host responses against subsequent infections [28,32,33]. Although induction of trained immunity (TI) by BCG vaccination leads to beneficial heterologous effects, the mechanisms underlying its persistence and magnitude remain unknown. Indeed, there is a need for clinical studies investigating the efficacy of the BCG vaccine in vulnerable populations who have a higher risk of being infected by COVID-19, such as HCWs, to gain insights into the underlying mechanism of heterologous effects of the BCG vaccine and confirm this hypothesis.
The influence of BCG on vaccine responses – a systematic review
Published in Expert Review of Vaccines, 2018
Petra Zimmermann, Nigel Curtis
Bacillus Calmette-Guérin (BCG) vaccine is one of the most widely used vaccines worldwide. In addition to protecting against tuberculosis, the vaccine has other important immunomodulatory effects.BCG vaccination reduces all-cause infant mortality in certain settings, decreases hospitalization rates due to respiratory infections and sepsis, is used in the treatment of bladder cancer, might decrease the incidence of eczema and other allergies, and is proposed to be beneficial in the treatment of autoimmune diseases.This review shows that BCG also influences the immune response to heterologous antigens: previous or concurrent administration of BCG vaccine is associated with higher levels of antibodies against hepatitis B, polio, pneumococcus, and influenza.Future studies should focus on investigating the influence of BCG vaccine strain and on the optimal timing of administration to exploit the immunomodulatory effects of BCG to improve vaccine efficacy and duration of protection.
Nanomaterials in tuberculosis DNA vaccine delivery: historical perspective and current landscape
Published in Drug Delivery, 2022
Xing Luo, Xiaoqiang Zeng, Li Gong, Yan Ye, Cun Sun, Ting Chen, Zelong Zhang, Yikun Tao, Hao Zeng, Quanming Zou, Yun Yang, Jieping Li, Hongwu Sun
Vaccination that promotes host immunity is the most effective intervention for TB treatment (Sia & Rengarajan, 2019); the Bacillus Calmette–Guerin (BCG) vaccine is approved worldwide for the prevention of TB meningitis (Puvacic et al., 2004) and miliary TB (Trunz et al., 2006). Currently, more than 90% TB vaccines are manufactured using five variants, namely, the 1173P2 (Pasteur), 1331 (Danish), 1077 (Glaxo), 172 (Japanese), and D2PB302 (China) strains (Li et al., 2020). Although TB vaccination is effective for infants (Schrager et al., 2020), its protective efficacy for adolescents and adults is low (Lowrie et al., 1994). Additionally, the effectiveness of vaccination varies greatly in different countries owing to significant differences in immune capacities (Abubakar et al., 2013). However, administering the BCG vaccine at an age of 3–5 years provides protection against active TB for the next 20 years (Mangtani et al., 2018). Furthermore, the BCG vaccine exhibits significant protective efficacy against persistent new M. tuberculosis infections, as indicated by recent studies (Nemes et al. 2018). According to data from the United States National Library of Medicine (http://clinicaltrials.gov), 149 studies on TB have been conducted in different phases of clinical trials (105 have been completed and 15 are in recruitment). However, these vaccines exhibit a poor ability to generate humoral and cell-mediated immunity (Ojha et al., 2020), necessitating the development of novel vaccines and delivery systems for TB.
Related Knowledge Centers
- Attenuated Vaccine
- Bladder Cancer
- Buruli Ulcer
- Immunosuppression
- Ulcer
- Leprosy
- Tuberculosis
- Vaccine
- NONtuberculous Mycobacteria
- Mycobacterium Bovis