A vaccine failure is when an organism develops a disease in spite of being vaccinated against it. Primary vaccine failure occurs when an organism's immune system does not produce antibodies when first vaccinated. Vaccines can fail when several series are given and fail to produce an immune response.
The name does not necessarily imply that the vaccine is defective. Most vaccine failures are simply from individual variations in immune response.
Causes for vaccine failure
- The vaccine virus may be a different serotype from the challenged virus.
- Maternal antibody which protects neonates may interfere with vaccine presentation.
- Some viruses, notably herpesviruses, are poorly neutralized and once established can spread between cells by fusion.
- The vaccine virus may become denatured or inactivated during storage or administration.
- Cell behavior was different than that of the live virus strain.
- The vaccine virus may be ineffective if it is manufactured incorrectly, for example containing the insufficient antigen or live virus.
References
Vaccine failure Wikipedia(Text) CC BY-SA