What are killed vaccine, Attenuated vaccine, Toxoid vaccine and Conjugated vaccine?
Answers
•Killed vaccine - These types of vaccines contain killed pathogens. Vaccines of cholera, plague and influenza are of this type.
•Attenuated vaccine - Virulence of pathogens are reduced by some laboratory techniques to prepare this vaccine. Vaccines of measles, mumps and rubella are of this type.
•Toxoid vaccine - Toxoid vaccines are prepared by inactivated toxins from pathogens. Vaccines of diphtheria, tetanus are of this type.
•Conjugated vaccine -Polysaccharide of bacterial capsule is attached with a protein to prepare a conjugated vaccine. Body's immune system can recognise this protein and keep it in memory for future immune response.
Answer:
Toxoid vaccines
Toxoid vaccines use a toxin (harmful product) made by the germ that causes a disease. They create immunity to the parts of the germ that cause a disease instead of the germ itself. That means the immune response is targeted to the toxin instead of the whole germ.
Like some other types of vaccines, you may need booster shots to get ongoing protection against diseases.
Toxoid vaccines are used to protect against:
Diphtheria
Tetanus
Killed or Inactivated Vaccines
One alternative to attenuated vaccines is a killed or inactivated vaccine. Vaccines of this type are created by inactivating a pathogen, typically using heat or chemicals such as formaldehyde or formalin. This destroys the pathogen’s ability to replicate, but keeps it “intact” so that the immune system can still recognize it. (“Inactivated” is generally used rather than “killed” to refer to viral vaccines of this type, as viruses are generally not considered to be alive.)
Because killed or inactivated pathogens can’t replicate at all, they can’t revert to a more virulent form capable of causing disease (as discussed above with live, attenuated vaccines). However, they tend to provide a shorter length of protection than live vaccines, and are more likely to require boosters to create long-term immunity. Killed or inactivated vaccines on the U.S. Recommended Childhood Immunization Schedule include the inactivated polio vaccine and the seasonal influenza vaccine (in shot form).
Subunit and Conjugate Vaccines
Both subunit and conjugate vaccines contain only pieces of the pathogens they protect against.
Subunit vaccines use only part of a target pathogen to provoke a response from the immune system. This may be done by isolating a specific protein from a pathogen and presenting it as an antigen on its own. The acellular pertussis vaccine and influenza vaccine (in shot form) are examples of subunit vaccines.
Another type of subunit vaccine can be created via genetic engineering. A gene coding for a vaccine protein is inserted into another virus, or into producer cells in culture. When the carrier virus reproduces, or when the producer cell metabolizes, the vaccine protein is also created. The end result of this approach is a recombinant vaccine: the immune system will recognize the expressed protein and provide future protection against the target virus. The Hepatitis B vaccine currently used in the United States is a recombinant vaccine.
Attenuated vaccine,
Viral: measles vaccine, mumps vaccine, rubella vaccine, live attenuated influenza vaccine (the seasonal flu nasal spray and the 2009 H1N1 flu nasal spray), chicken pox vaccine, smallpox vaccine, oral polio vaccine (Sabin), rotavirus vaccine, and yellow fever vaccine.