Vaccination and Immunity

Antibodies are small proteinaceous substance made by the immune cells. Antibodies attach to proteins and other chemicals in the body, which they recognise to be not normally found in the body ('foreign'). The foreign proteins and chemicals that antibodies attach to are called as antigens. Thus, the correct answer is option A.

Explanation: Oral cholera vaccines provide only short-term immunity, which lasts for around 2 to 3 years.

All the above options are functions of local bodies. The local bodies act at the level of cities, towns and large villages.

Passive immunity is the transfer of active humoral immunity of ready-made antibodies (exogenous). Passive immunity can occur naturally, when maternal antibodies are transferred to the fetus through the placenta, and it can also be induced artificially when high levels of antibodies specific to a pathogen or toxin are transferred to non-immune persons through blood products that contain antibodies.

Active immunity is the induction of immunity after exposure to an antigen. Antibodies are created by the recipient and may be stored permanently due to the activation of memory cells which recognizes the same antigen in future and destroy them. Active immunity can occur naturally when a microbe or other antigen is received by a person who has not yet come into contact with the microbe and has no pre-made antibodies for defence. The immune system will eventually create antibodies for the microbe, but this is a slow process.

Antivenum which is injected to body in case of snakebite, contain antibodies that disable a particular venom's toxins. Antivenom is less able to reverse the damage already happened in the body. So, quick injection is a must. So, the statement A is correct.

Innate immunity includes anatomical and physiological barriers, inflammation, complement activation, cytokine secretion, phagocytosis. Cytokines play an important role in the innate immune response. It fights directly against the virus by preventing its replication. At the same time, cytokines activates NK cells and macrophages, which produce more cytokines. Also, virus infected cells secrete proteins called interferons , which protect non-infected cells from further infection.

In the case of tetanus toxoid, when it administered in a newborn, the vaccine contains detoxified tetanus toxins (which does not lose their immunogenic properties). The administration of the tetanus toxoid stimulates the body to produce protective antibodies against the toxins.
In the case of administration of anti-venin against snake bite or anti-tetanus serum the, the doses contain antibodies which go and attack their target antigens in the body. The passage of IgG across placenta also helps the fetus to fight infections directly.
So, the correct answer is ' Administration of tetanus toxoid to newly born'.

Active immunity is the type of immunity in which antibodies are produced against a specific antigen. This type of immunity takes time in order to produce enough antibodies to fight the pathogen. This immune response is long lived and is more effective. It results in the immunological memory which remains for life time. It is used for prophylaxis to increases body resistance. Passive immunity is a type of immunity in which antibodies are obtained from outside the body. An example includes antibodies obtained from mother through the  breast milk. This immune response is short lived and less effective. It does not have any immunological memory. It is used for treatment of acute infection.

Artificially acquired active immunity can be induced by a vaccine, a substance that contains antigen. A vaccine stimulates a primary response against the antigen without causing symptoms of the disease. 

Toxoid is a type of vaccines obtained from the toxin and are inactivated and made harmless by chemical or heat treatment. Eg- tetanus toxoid is obtained by Clostridium tetani. These vaccines provide artificial active acquired immunity. So, the correct answer is 'Artificial active acquired immunity'.

Passive immunity is the transfer of active humoral immunity in the form of ready-made antibodies, from one individual to another. Passive immunity can occur naturally when maternal antibodies are transferred to the fetus through the placenta and can also be induced artificially when high levels of human (or horse) antibodies specific for a pathogen or toxin are transferred to non-immune individuals. Passive immunization is used when there is a high risk of infection and insufficient time for the body to develop its own immune response, or to reduce the symptoms of ongoing or immunosuppressive diseases.

Live, attenuated vaccines contain a living microbe that has been weakened in the lab so it cannot cause disease. Because a live, attenuated vaccine is the closest thing to a natural infection, these vaccines elicit strong cellular and antibody responses and often confer lifelong immunity with only one or two doses. Vaccines against measles, mumps, and chickenpox, for example, are made by this method. 

A vaccine is the killed or live suspension of microorganism which helps to activate the immune response. The agent stimulates the body's immune system to recognize the agent as a threat, destroy it and keep a record of it so that the immune system can more easily recognize and destroy any of these microorganisms that it later encounters.