vaccine types and technologies activity

vaccine types

• live attenuated (live)

• inactivated (killed)

live vaccines

• attenuated (weakened)

• must replicate in the body to stimulate an immune response

  • may not be suitable for patients with immunosuppression

  • circulating antibodies may inactivate the vaccine

• stimulates both humoral (antibodies) and cellular (memory cells) immune responses

  • more persistent immunity

routinely recommended live vaccines

• LAIV4 - live attenuated influenza vaccine

• RV1, RV5 - rotavirus

• VAR - varicella

• MMR - measles, mumps, rubella

• MMRV - measles, mumps, rubella, varicella

inactivated vaccines

• killed virus or bacteria or component

  • various fractions: subvirions, subunits, polysaccharides, toxoids, recombinant antigens, virus-like particles

• unable to replicate - does not cause disease

• stimulates humoral immunity (antibodies)

• may be given to people with immunosuppression or those receiving blood products

what are the broad, major categories in which vaccines are classified?

a) injectable vaccines

b) influenza vaccines

c) inactivated vaccines

d) live attenuated vaccines

c, d

inactivated vaccine manufacturing

• can be produced using a variety of technologies

• take the form a weakened whole virus or bacteria

• can’t cause the disease they are manufactured to prevent

inactivated vaccines: polysaccharide

• polysaccharide (non-protein)

• part of the external capsules of bacteria

• stimulates B cells without T helper cells

• not used in children younger than age 2 years

• conjugated

  • “linked” to proteins

  • works well in infants

  • boosts antibody responses on repeat vaccination

polysaccharide vs conjugate polysaccharide vaccines (inactivated)

• polysaccharide

  • stimulate T-cell independent immunity

    • stimulate B cells without assistance of helper T cells

    • short-lived immunity

    • no booster effect

    • not consistently immunogenic in children younger than 2 years

• conjugate polysaccharide

  • protein carrier

  • stimulate T-cell dependent immunity

    • helper T cells involved

    • produce immunologic memory

    • result in booster effect upon subsequent exposure

    • increased immunogenicity in children younger than 2 years

inactivated vaccines: recombinant subunit

• recombinant

  • produced by genetic engineering

  • may contain no actual virus or a modified strain of a virus

• ex:

  • HepB

  • HPV

  • RZV

  • RIV

inactivated vaccines: toxoids

• toxoids

  • subunit vaccines

  • inactivate a biological toxin

• ex:

  • tetanus toxoid

  • diphtheria toxoid

inactivated vaccines: cellular

• cellular

  • whole viruses or bacteria

  • subunits (fractions)

• ex:

  • DTP (1948)

  • DTaP (used today)

routinely recommended inactivated vaccines

• DTaP, Tdap, Td, DT - diphtheria, tetanus, acellular pertussis

• Hib - haemophilus influenzae type B

• HepA - hepatitus A

• HepB - hepatitus B

• RZV - recombinant zoster vaccine

• 9vHPV - human papillomavirus vaccine

• IIV, RIV, ccIIV - inactivated influenzae vaccine

• MCV4, MenACWY-D, MenACWY-CRM, MenB-FHbp, Men-4C - meningococcal conjugate vaccine

• PCV15, PCV20, PCV21, PPSV23 - pneumococcal polysaccharide vaccine, pneumococcal conjugate vaccine

• IPV - inactivated polio vaccine

• RSVpreF, RSVpreF3 - respiratory syncytial virus

• other combinations of above

  • note: COVID-19 vaccines are non-live (non-replicating) vaccines

what clinical factors need to be considered before administering a live attentuated vaccine? SATA

a) inactivated vaccines administered recently

b) patients who currently are immunocompromised

c) live attenuated vaccines administered recently

d) patient’s current fall risk

b, c

evolution of the flu shot

• 1940s Egg-based

  • used for over 70 years

  • candidate vaccine viruses (CVVs) grown into eggs to replicate the virus

  • requires a large number of chicken eggs and several months to produce

  • IIV, IIv, LAIV

• 2012 Cell-based

  • approved by FDA in 2012

  • CVVs are given to the vaccine manufacturer under guidance from the CDC

  • CVVs are inoculated into cultured mammalian cells to replicate

  • process allows for a faster production timeline

  • ccIV

• 2013 Recombinant

  • approved by FDA in 2013

  • do not require a CVV to start

  • DNA for making hemagglutinin is added to baculovirus

  • faster production timeline

  • RIV

vaccine technology: mRNA

• used since the early 2010s

• inject genetic instructions for a host to produce a particular subunit of a virus

• mRNA is unstable if injected in the body and can be easily broken down

• encapsulating the mRNA in a lipid nanoparticle improves stability but requires more stringent storage

vaccine technology: virus-like particles (VLPs)

• multiprotein structures that mimic authentic viruses

• lack the genetic material of the virus

• hepatitus B vaccine uses a specific VLP in the hepatitis B surface antigen

vaccine adjuvants

• ingredient in some vaccines that stimulate a stronger immune response

• generally developed and patented by manufacturers

• may cause more local and systemic reactions

which of the following is classified as a live vaccine?

a) IIV

b) human papillomavirus vaccine (9vHPV)

c) recombinant zoster vaccine (RZV)

d) measles, mumps, and rubella (MMR)

e) DTap

f) Tdap

d