Vaccination and Immunity

IgA immunoglobulin protects mucosal surfaces; prevents attachment of pathogens to epithelial cells.

Smallpox vaccination uses weakened (attenuated) live virus - specifically the vaccinia virus, which is similar enough to smallpox to stimulate immunity but much safer. Killed germs would not produce effective immune memory. Live antibodies are not administered directly. Activated germs would cause disease rather than immunity.

The yellow fever vaccine was formulated in 1932. The vaccine was developed by Max Theiler and colleagues, leading to Theiler's Nobel Prize in 1951. The correct answer is A (1932), not the other years listed. This was a major breakthrough in tropical medicine.

These are the type of vaccines that are used for diptheria and tetanus. In this type of vaccine, the toxoids produced by the bacteria are made harmless. Toxoids are used to stimulate antibody production, but there is no risk of infection by the pathogen.

There are at least 93 serotypes in the world. Though there are 23 prevalent serotypes that cause disease in different parts of the world, but no switching of the bacterium between serotypes is there. Infections with these organisms are common and often infect those with antibody, or innate or combined deficiencies.

Salk polio vaccine is sterilised by formaldehyde (gaseous form).

OPV stands for Oral Polio Vaccine, which is administered orally (through drops) rather than by injection. It's a live attenuated vaccine used to immunize against poliovirus.

Jonas Salk developed the inactivated polio vaccine (IPV) in 1955. While the option lists 'J. Salk,' his full name was Jonas Salk, so this refers to the same person. Albert Sabin developed the oral polio vaccine (OPV) later.

Hepatitis B vaccine is a virus-like particle based vaccine. Virus-like particle vaccines consist of viral proteins derived from the structural proteins of a virus. These proteins can self-assemble into the virus-like particles which are noninfectious as they lack viral nucleic acid.

Vaccination confers active artificial adaptive immunity. It is artificial because it develops through deliberate action of vaccination. It is active because immunity is induced in the host and lasts longer. It is adaptive because it is specific in action.

Artificial passive immunisation is done for immediate protection.

Baxter Inc. was the first company to roll out an H1N1 (swine flu) vaccine in 2009 during the global pandemic. The company received approval for its vaccine and began distribution during the height of the H1N1 outbreak. This was part of the global response to the 2009 swine flu pandemic.

Subunit vaccines are a development of the killed vaccine approach. Examples are: Hepatitis B vaccine (HBV), Pertussis (part of DTaP combined immunisation) vaccine, Pneumococcal vaccine, Meningococcal vaccine, etc.

In herd immunity, only some of the inhabitants are immunised and others develop immunity themselves. It is a form of indirect protection from infectious diseases that occurs when a large percentage of population has become immune to an infection. It provides a measure of protection for individuals who are not immune.

Smallpox vaccine, the first successful vaccine to be developed, was introduced by Edward Jenner.