VACCINATION - How Do Vaccinations Affect The Genotype?
                     VACCINATION: HOW DO VACCINATIONS 
AFFECT THE  GENOTYPE
What is Vaccination?
Vaccination is the administration of a vaccine to help the 
immune system develop immunity from a disease. Vaccines 
contain a microorganism or virus in a weakened, live or killed 
state, or proteins or toxins from the organism.
Source: Wikipedia
Types of Vaccine
Based on a number of these factors, scientists decide which 
type of vaccine they will make. There are several types of 
vaccines, including:
• Inactivated vaccines
• Live-attenuated vaccines
• Messenger RNA (mRNA) vaccines
• Subunit, recombinant, polysaccharide, and conjugate 
vaccines
• Toxoid vaccines
• Viral vector vaccines
Source: www.hhs.gov
Inactivated vaccines
• Inactivated vaccines use the killed version of the germ 
that causes a disease.
• Inactivated vaccines usually don’t provide immunity 
(protection) that’s as strong as live vaccines. So you may 
need several doses over time (booster shots) in order to 
get ongoing immunity against diseases.
• Inactivated vaccines are used to protect against:
– Hepatitis A
– Flu (shot only)
– Polio (shot only)
– Rabies
Source: www.hhs.gov
Live-attenuated vaccines
• Live vaccines use a weakened (or attenuated) form of the 
germ that causes a disease.
• Because these vaccines are so similar to the natural 
infection that they help prevent, they create a strong and 
long-lasting immune response. Just 1 or 2 doses of most 
live vaccines can give you a lifetime of protection against 
a germ and the disease it causes.
• Live vaccines are used to protect against:
– Measles, mumps, rubella (MMR combined vaccine)
– Rotavirus
– Smallpox
– Chickenpox
– Yellow fever
Source: www.hhs.gov
Messenger RNA vaccines
• Researchers have been studying and working with mRNA 
vaccines for decades and this technology was used to 
make some of the COVID-19 vaccines. 
• mRNA vaccines make proteins in order to trigger an 
immune response. 
• mRNA vaccines are used to protect against:
– COVID-19
Source: www.hhs.gov
Subunit, recombinant, polysaccharide, and 
conjugate vaccines
• Subunit, recombinant, polysaccharide, and conjugate 
vaccines use specific pieces of the germ—like its protein, 
sugar, or capsid (a casing around the germ).
• These vaccines are used to protect against:
– Hib (Haemophilus influenzae type b) disease
– Hepatitis B
– HPV (Human papillomavirus)
– Whooping cough (part of the DTaP combined 
vaccine)
– Pneumococcal disease
Source: www.hhs.gov
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.
• Toxoid vaccines are used to protect against:
– Diphtheria
– Tetanus
Source: www.hhs.gov
Viral vector vaccines
• Viral vector vaccines use a modified version of a different 
virus as a vector to deliver protection. 
• Several different viruses have been used as vectors, 
including influenza, vesicular stomatitis virus (VSV), 
measles virus, and adenovirus, which causes the common 
cold.
• Viral vector vaccines are used to protect against:
– COVID-19
Source: www.hhs.gov
Replicating 
• Replicating viral vectors retain the ability to make new 
viral particles alongside delivering the vaccine antigen 
when used as a vaccine delivery platform. 
• As with live attenuated whole pathogen vaccines this has 
the inherent advantage as a replicating virus that it can 
provide a continuous source of vaccine antigen over an 
extended period of time compared to non-replicating 
vaccines, and so is likely to produce a stronger immune 
response. 
• A single vaccine may be enough to give protection. 
Source: vk.ovg.ox.ac.uk
Non-replicating
• Non-replicating viral vectors do not retain the ability to 
make new viral particles during the process of delivering 
the vaccine antigen to the cell. 
• This is because key viral genes that enable the virus to 
replicate have been removed in the lab. This has the 
advantage that the vaccine cannot cause disease and 
adverse events associated with viral vector replication are 
reduced. 
Source: vk.ovg.ox.ac.uk