14. Vaccinations I Flashcards
(27 cards)
What is the annual death toll caused by infectious diseases?
Approximately 2.5 million deaths annually
This statistic highlights the significant impact of infectious diseases on public health.
What is the origin of the term ‘vaccine’?
Derived from ‘vacca’, Latin for cow
This term originated from Edward Jenner’s use of cowpox to inoculate against smallpox.
What major vaccines did Louis Pasteur develop in the 1880s?
Vaccines for cholera and rabies
Pasteur was the first to use attenuated forms of infectious agents in vaccine development.
What percentage of a population must be immune to achieve herd immunity?
≥95%
Achieving this level of immunity protects the entire community, including those who cannot be vaccinated.
What is passive immunity?
Immunity provided by pre-formed antibodies generated outside the host
This type of immunity does not activate the recipient’s immune system.
List two sources of passive immunity.
- Natural: Maternal antibodies
- Artificial: Direct administration of antiserum/antibodies
Maternal antibodies can be transferred through the placenta or breast milk.
What is active immunity?
Immunity developed through direct exposure to antigens
This can occur naturally through infection or artificially through vaccination.
What are the two arms of the immune system activated by vaccines?
- Innate immune system
- Adaptive immune system
Both systems play crucial roles in the body’s response to vaccines.
What are adjuvants in vaccines?
Substances added to enhance immune response
They are particularly helpful for inactivated or partial pathogens that are less immunogenic.
Name one example of a live attenuated vaccine.
Measles
Live attenuated vaccines use weakened but viable pathogens to elicit a strong immune response.
What is antigenic drift?
Small point mutations in surface proteins of viruses
This gradual change can prevent recognition by existing antibodies, necessitating annual vaccine updates.
What is antigenic shift?
Major changes through genetic reassortment
This can occur when different influenza strains co-infect a cell, potentially leading to pandemic strains.
What are the key characteristics of passive immunity?
- Does not activate the recipient’s immune system
- Does not induce memory response
- Limited duration of protection
These characteristics differentiate passive immunity from active immunity.
What are the steps involved in vaccine processing?
- Antigen introduction
- Antigen uptake by dendritic cells
- Dendritic cell migration to lymphatic tissues
- Antigen presentation to T cells
- T cells educate B cells and cytotoxic T cells
- Development of primary immune response
- Formation of memory response
These steps outline how vaccines stimulate an immune response.
True or False: Vaccines can cause disease.
False
Vaccines are designed to provide immunity without causing the disease itself.
What is the role of memory cells in the immune response?
They provide a rapid, stronger response upon secondary exposure to an antigen
This is crucial for long-lasting immunity, as seen in some vaccines.
Fill in the blank: The mechanism of action of adjuvants includes the _______ effect, which maintains antigen at the injection site longer.
Depot
This effect enhances the immune response by prolonging the presence of the antigen.
List three types of vaccines.
- Live attenuated vaccines
- Inactivated vaccines
- Recombinant viral vector vaccines
These categories reflect different approaches to vaccine development.
What is the effectiveness of the measles vaccine since its introduction in 1963?
Nearly eradicated
This demonstrates the significant impact of vaccination programs on infectious diseases.
What are some challenges to achieving herd immunity?
- Concerns about adverse effects
- Cost of vaccines
- Access and infrastructure issues in developing regions
These factors can hinder vaccination efforts and public health initiatives.
What types of pathogens are used in inactivated vaccines?
Killed pathogens (heat/chemicals)
These vaccines often elicit a weaker immune response compared to live attenuated vaccines.
What role do T cells play in the immune response to vaccines?
They educate B cells and cytotoxic T cells
This education is essential for a coordinated immune response.
What is the purpose of using aluminum salts in vaccines?
To create a depot effect
Aluminum salts have been used for over 70 years to enhance vaccine efficacy.
What is the definition of herd immunity?
Occurs when a sufficient percentage of a population is immune
This concept is key to protecting individuals who cannot be vaccinated.
