Vaccines at the human-animal interface

Question 1

What is the animal human interface in health and disease?

Answer 1

Humans are dependant on animals but this close contact causes diseases. Human health and animal health is interdependant (giving rise to one health).

Question 2

What is a zoonosis?

Answer 2

A human infection acquired from an animal

Question 3

Give a breif description of how vaccines were found (poxvirus)?

Answer 3

Smallpox caused by variola virus (DNA poxvirus) was killing lots of people.

Edward Jenner realised that milk maids who’d previously had cow pox did not get this disease.

He infected a child with cow pox and then small pox and immunological memory happened resulting in the kid not dying.

Global eradication of small pox = 1980

Question 4

What is vaccine scepticism?

Answer 4

People not being sure of vaccines and thinking they are going to be bad for them.

Question 5

What is morbilliviruses and

Answer 5

Negative strand RNA viruses that can infect humans (measles), cattle (rinder perst), peste des petits rimunants (sheep, goats) and canine distemper (dogs) which are highly contagious via respiratory routes which cause immunosuppresion and mortality.

There is no medical cures but there is however vaccines for these

Question 6

The measles vaccine?

Answer 6

Live attenuated vaccine

Question 7

What did measles cause and when was it common?

Answer 7

Common in children

Mild = middle ear infections, diarrhoea, pneumonia

Rare = blindness and encephalitis

Question 8

What was the MMR vaccine wrongly associated with causing thousands of deaths through people not getting the vaccine?

Answer 8

Autism

Question 9

Do we have the means to eradicate measles and how would we do this?

Answer 9

Yes - you need to vaccinate enough of the population so that those who cannot be vaccinated will be protected (herd immunity) and better surveillance.

Question 10

What are the WHO milestones for measles?

Answer 10

Vaccinating more children in their first year of life
Reducing incidence of disease
Reducing mortality

Question 11

What were the measles deaths like in 2019 and why?

Answer 11

Highest number in 23 years because of parents not vaccinating children.

Question 12

Has rinderpest been eradicated and how?

Answer 12

Yes because this is only found in animals and therefore they cant massively protest getting the vaccine

Question 13

What is Kochs postulate?

Answer 13

general guidelines to identify infectious microbes that could be detected with the available methods and that were demonstrably alive

Question 14

What are benefits of live attenuated vaccines?

Answer 14

Induce strong, protective immunity

Question 15

What are risks of live attenuated vaccines?

Answer 15

Reaccurance of the disease in non immunised or immunocomprimised people.

Question 16

What do vaccine platform technologies provide?

Answer 16

Generic approaches to vaccine design and knowledge of immune correlates can accelerate vaccine development

Question 17

What is involved in the target product profile?

Answer 17

You must thinks about stability, purchase price DIVA, frequency of delivery, duration of immunity, induction of cellular immunity, induction of humoral immunity, route of delivery and multi-valency

Question 18

what are types of vaccines?

Answer 18

Live attenuated
Killed
Subunit - toxoid, polysaccharide, recombinant antigen with adjuvants
Delivery systems/platform technologies (nanoparticles, vectors, nucleic acids)

Question 19

How can vaccines induce immunity? (Humoral, antibodies and cell mediated immunitiy)

Answer 19

Humoral immunity (effective against extracellular infections),
Antibodies can neutralise viruses but have limited efficacy against intracellular infections.
Cell-mediated immunity (controls intracellular infections)

Question 20

How do live vaccines compare to killed/subunit vaccines in the immune response?

Answer 20

Live vaccines elicit a better immune response than killed/subunit vaccines however killed/subunit vaccines tend to be safer but need adjuvants.

Question 21

What are vaccine platform technologies?

Answer 21

Generic technologies can be applied to vaccines through nanoparticles which have recombinant proteins antigens, vectors encoding antigens of interest, nucleic acid vaccines etc.

These have different properties and offer choice and can accelerate regulatory approval for new vaccines

Question 22

What was the first human viral-vector vaccines and

Answer 22

ChimeriVax and other viral vectors arent limited to vaccinating against viral disease and epidemics and are now being developed to tackles TB, HIV/AIDs, malaria.

Commonly used vectors include MVA, VSV and Adenoviruses

Question 23

What are some nucleic acid vaccines?

Answer 23

Human mRNA vaccines
DNA vaccine
Self-amplifying RNA vaccines aren’t approved for use

Question 24

How does the immune system react to vaccines?

Answer 24

Recombinant adenoviral genome containing promotor, immunogen gene or poly A are injected intramuscularly which causes viral induced activation of the innate signals without any viral particles formed. The immunogen is degraded and expressed on MHC class 1 causing CD8+ T cells to activate

Question 25

What is the DHSC UK vaccine network?

Answer 25

This is a network which contains all information on possible epidemics and how you would stop them

Question 26

How were viral vectored vaccines used in the Ebola outbreak?

Answer 26

ERVEBO a live attenuated, recombinant vesicular stomatitis virus besed vector vaccine expressing the enola virus glycoprotien was used.

Question 27

Why was the covid response so rapid?

Answer 27

Prior knowledge of coronavirus biology, immunology and vaccine platform response

Also lots of countries and many affected individuals.

Altered regulatory processes e.g. they could monitor in real time instead of spending years going through a binder of information

Question 28

How do the different covid vaccines compare to one another (mRNA, AdV, rProteins)

Answer 28

All used the same S protein

mRNA induced higher antibody levels thans the others. AdV induce better cellular response and CD8+ induction and a Th1 bias associated with better outcomes

Question 29

How was the safety of covid mRNA vaccines monitored?

Answer 29

VAERS - this involved inputting your data of symptoms into the phone.

They found no correlation between deaths and vaccines

Question 30

How was rift valley fever an example of one vaccine one health?

Answer 30

Mosquito born virus infecting humans was fatal and caused bu ChAdOx1 encoding RVFV Gn and Gc.

A single IM injection made neutralising antibodies protecting against transmission into humans.