The infection is a state in which the immune system is weak to fight against the pathogen. The infection can be prevented by maintaining a healthy population. The proper food will provide nutrients which make the body strong and healthy. This allows more production of immune cells to fight the infection. The healthy population are less likely to acquire the diseases and there will be less chances of epidemics.

The vaccine is made from a virus either killed, weakened or attenuated, which is introduced into the blood. This process is known as vaccination or immunization. The vaccine can be used to inject the antigen or the antibodies which provide protection against the respective disease by the production of antibodies by the plasma cells. The infectious diseases are transmitted from one infected person to the other person directly. These diseases can be prevented with the help of vaccination.

Tuberculosis is a disease caused by the bacterium Mycobacterium tuberculosis. Influenza is caused by Haemophilus influenzae.  The infected person coughs and sneezes. These diseases are transmitted through the air droplets while sneezing and coughing. The causative agent survives in the air droplets and through the air, the disease is transmitted to the other person. 

Early symptoms of active TB can include weight loss, fever, night sweats and loss of appetite. Symptoms may be vague, however, and go unnoticed by the affected person. For some, the disease either goes into remission (halts) or becomes chronic and more debilitating with cough, chest pain and bloody sputum (saliva). 

Bacillus Calmette–Guérin (BCG) vaccine is a vaccine which is primarily used against tuberculosis. In countries where tuberculosis or leprosy is common, one dose is recommended in healthy babies as close to the time of birth as possible. In areas where tuberculosis is not common, only children at high risk are typically immunized, while suspected cases of tuberculosis are individually tested for and treated.

BCG vaccine stands for Bacillus Calmette-Guerin. It is a vaccine against tuberculosis and for the treatment of some bladder cancers.
So, the correct answer is option A.

BCG, or Bacille Calmette-Guerin, is a vaccine for tuberculosis (TB). It is made from weakened tuberculosis bacteria that infect cows, similar to the human form of tuberculosis. The vaccine is 70-80% effective against the most severe forms of TB, such as TB meningitis in children.

Bacille Calmette-Guerin (BCG) is commonly used against tuberculosis. It is normally given to children as it has been shown to provide very good protection against the disseminated forms of TB in children, including TB meningitis. The other diseases do not have any vaccines yet.

Although your body may harbour the bacteria that cause tuberculosis, your immune system usually can prevent you from becoming sick. Several signs and symptoms of active TB include: coughing that lasts three or more weeks, coughing up blood, chest pain, or pain with breathing or coughing, unintentional weight loss, fatigue, fever, loss of appetite etc. 

Tuberculosis is a primarily an airborne disease. The causative agent for the disease is Mycobacterium tuberculosis. The bacteria are spread from person to person in tiny microscopic droplets through the air. 

Tuberculosis can also affect other parts of your body, including your kidneys, spine or brain. When TB occurs outside your lungs, signs and symptoms vary according to the organs involved. For example- tuberculosis of the spine may give you back pain and tuberculosis in your kidneys might cause blood in your urine. 

Tuberculosis is a disease caused by the bacterium Mycobacterium tuberculosis. The symptoms are a loss of the body weight, fatigue, there is a cough for more than two weeks with mucus and blood, the color of the sputum is yellowish or green. The X-ray shows spots in the lungs due to the infection.

Symptoms of active Tuberculosis can depend on what part of the body has been infected. The symptoms include cough lasting 3 weeks or more, pain in the chest area, a cough that brings blood or mucus, chills, fever, night sweats, loss of appetite, weight loss, and fatigue. Tuberculosis can also affect a person's brain, bones, kidneys, or spine.

Tuberculosis is a disease caused by the bacterium Mycobacterium tuberculae. The symptoms include loss of body weight, cough with mucus and blood and the color of the sputum turns to yellowish or green. The disease is transmitted through the air droplets while sneezing and coughing. 

BCG stands for Bacillus Calmette-Guerin. BCG vaccine is given for protection against tuberculosis as a preventive measure. Since tuberculosis is an airborne disease, the person who is infected by tuberculosis should be kept in isolation so that he does not spread bacteria by coughing or sneezing. Also, to protect oneself from getting tuberculosis, one should wear a facemask so that tuberculosis bacteria is not inhaled and does not cause infection. 

• Tuberculosis is an infectious disease usually caused by Mycobacterium tuberculosis bacteria. Tuberculosis generally affects the lungs, but can also affect other parts of the body. The symptoms of active TB is a chronic cough with blood-containing sputum, fever, night sweats, and weight loss.

• • Tuberculosis responsible for causing maximum deaths in children. If not diagnosed and treated at early stages.

• So, the correct answer is 'Tuberculosis'.

BCG, or bacille Calmette-Guerin, is a vaccine for tuberculosis (TB) disease. The BCG vaccine is made from a weakened form of a bacterium closely related to human TB. The vaccine is 70-80% effective against the most severe forms of TB, such as TB meningitis in children.

The Mantoux tuberculin skin test (TST) or the TB blood test can be used to test for M. tuberculosis infection. The Mantoux tuberculin skin test is performed by injecting a small amount of fluid called tuberculin into the skin in the lower part of the arm. The test is read within 48 to 72 hours by a trained health care worker, who looks for a reaction (induration) on the arm. A posterior-anterior chest radiograph is used to detect chest abnormalities in TB. Lesions may appear anywhere in the lungs and may differ in size, shape, density, and cavitation. The presence of acid-fast-bacilli (AFB) on a sputum smear or other specimen often indicates TB disease.  A positive culture for M. tuberculosis confirms the diagnosis of TB disease. 

BCG vaccine provides immunity or protection against tuberculosis (TB). The vaccine may be given to persons at high risk of developing TB. When used to protect against TB, it is injected into the skin. 

Tuberculosis (TB) is a bacterial disease cased by Mycobacterium tuberculosis. Though TB typically attacks the lungs, it can also target the kidney, spine and brain. Once the bacteria is spread, Mycobacterium tuberculosis grows in the throat and lungs after two to eight weeks after infection. It then can either be fought off entirely by the immune system, remain in the body in a latent state, or develop into active TB. If it is active TB, it can then become skeletal TB, genital tract TB, urinary tract TB, CNS TB, gastrointestinal TB, adrenal TB or cardiac TB. The tissue damage results from the lymphoid cells releasing toxic substances rather than from bacterial toxins. The bacteria actually cause macrophages to form granulomas. These granulomas can liquefy and cause bacteria to spill into the lungs to cause large  cavities to form active TB. The bacteria breed in the cavities. Thus, the tissue destruction results from cell-mediated hypersensitivity.

Latent TB is the condition in which you have a TB infection, but the bacteria remain in your body in an inactive state and cause no symptoms. Latent TB, also called as an inactive TB or TB infection, isn't contagious. It can turn into active TB, so treatment is important for the person with latent TB and to help control the spread of TB in general. 

Tuberculosis is treated with isoniazid, rifampicin, pyrazinamide and ethambutol or streptomycin. Rifampicin is a broad spectrum antibiotic and hence can prevent other bacterial infections also. Rifampicin serves as the potent inhibitor of bacterial RNA synthesis. 

Latent TB is the condition in which you have a TB infection, but the bacteria remain in your body in an inactive state and cause no symptoms. Latent TB, also called as an inactive TB or TB infection, is not contagious. It can turn into active TB, so treatment is important for the person with latent TB and to help control the spread of TB in general.

Symptoms of active TB can depend on what part of the body has been infected. If active TB occurs in the lungs, the symptoms can include a cough lasting 3 weeks or more, pain in the chest area, breathing difficulty, weight loss, cough that brings blood or mucus, chills, fever, and fatigue. TB can also affect a person's brain, bones, kidneys, or spine.

Chemoprophylaxis is the method of administrating medicines for preventing disease. It is also called as Chemoprevention. Tuberculosis chemoprophylaxis is used to prevent the infection or it is also used to avoid development of disease in a person who is having latent TB. Isoniazid drug is most commonly given as a preventive measure. 

Symptoms of active TB can depend on what part of the body has been infected. If active TB occurs in the lungs, the symptoms can include a cough lasting 3 weeks or more, pain in the chest area, breathing difficulty, weight loss, cough that brings blood or mucus, chills, fever, and fatigue. TB can also affect a person's brain, bones, kidneys, or spine.

The most common type of TB in children is pulmonary TB. In about 70 -80% of the children affected by TB, it is pulmonary TB. The rest 20% is non-pulmonary TB. The source of infection for children getting pulmonary TB is inhalation of TB bacteria which generally settles in lungs.

BCG stands for Bacillus Calmette-Guerin. BCG vaccine is given for protection against tuberculosis as a preventive measure. Isoniazid is an antibiotic used as a first-line agent for the prevention and treatment of both latent and active tuberculosis. Ethambutol is used to treat active TB infection along with other tuberculosis medications, such as isoniazid, rifampicin and pyrazinamide. 

The organisms or agents which are responsible for the development of a disease or any infection is known as a pathogen. The ability of the organism to cause disease is pathogenicity. The microbes like the virsues, bacteria, and fungi are known as the pathogens which cause a certain type of infection. 

AIDS (Acquired immunodeficiency syndrome) is an infection which is caused by Human immunodeficiency virus (HIV). The causative agent of the disease is a virus and so the disease can spread from one person to the other by sexual contact.