Vaccines Overview and Types

These flashcards cover key concepts and vocabulary related to different types of vaccines and their characteristics.

Live attenuated vaccines

Vaccines produced by weakening the pathogen so it can’t cause disease but still replicates in the body.

Advantages of live attenuated vaccines

Strong, long-lasting immune response; often requires only 1–2 doses; mimics natural infection.

Examples of live attenuated vaccines

MMR, Varicella, Intranasal Influenza, Yellow Fever.

Disadvantages of live attenuated vaccines

May cause mild infection symptoms; not safe for immunocompromised individuals; requires refrigeration.

Inactivated vaccines

Vaccines made with pathogens that have been killed using heat, chemicals, or radiation.

Advantages of inactivated vaccines

Cannot cause disease; safer for immunocompromised individuals; stable for storage and transport.

Examples of inactivated vaccines

Polio (IPV), Hepatitis A, Rabies, Injectable Influenza.

Disadvantages of inactivated vaccines

Weaker immune response; usually requires booster doses.

Toxoid vaccines

Vaccines using inactivated bacterial toxins to elicit immunity against the toxin, not the bacteria.

Advantages of toxoid vaccines

Targets harmful toxin rather than the organism; produces strong antitoxin response.

Examples of toxoid vaccines

Tetanus, Diphtheria.

Disadvantages of toxoid vaccines

Does not protect against infection by the bacteria itself; requires booster shots.

Subunit (or cellular) vaccines

Vaccines that use only specific antigenic parts (proteins or polysaccharides) of a pathogen.

Advantages of subunit vaccines

Minimal side effects; safe for immunocompromised people; cannot cause disease.

Examples of subunit vaccines

Pertussis (DTaP), Hepatitis B, HPV, Recombinant Influenza.

Disadvantages of subunit vaccines

May require booster; weaker immune response than live vaccines.

Conjugate vaccines

Vaccines made with polysaccharide antigens linked to a protein to improve immune response, especially in young children.

Advantages of conjugate vaccines

Effective in infants and children; produces strong, lasting immunity.

Examples of conjugate vaccines

Hib, Pneumococcal (PCV13), Meningococcal (MCV4).

Nucleic acid vaccines

Vaccines that use genetic material from the pathogen (DNA or mRNA) to instruct cells to produce the antigen.

Advantages of nucleic acid vaccines

Fast to develop; strong immune response; no live virus used.

Examples of nucleic acid vaccines

COVID-19 mRNA (Pfizer, Moderna), DNA vaccines (in trials).

Disadvantages of nucleic acid vaccines

Newer technology (limited long-term data); requires very cold storage.