Poster Presentation

Question 1

Intro

Answer 1

• The other prevention method of RSV is through vaccination
• The vaccines available to protect against RSV are categorised into several types, each working differently to target the virus
• The main types include

Question 2

Main types of RSV vaccines

Answer 2

• The main types include mRNA vaccines, which instruct cells to produce viral proteins to trigger an immune response through mRNA
• Live attenuated vaccines, which use weakened forms of the virus
• Subunit vaccines which only use parts of the virus, like proteins, to stimulate immunity
• And recombinant vector based vaccines, which introduce viral proteins into the body using a different, harmless virus as a carrier

Question 3

Vaccines

Answer 3

• The two vaccines recently approved by Australia’s Therapeutic Goods Administration to combat RSV are Arexvy and Abrysvo, which are both protein subunit vaccines.
• They are specifically designed to target the prefusion form of the RSV F protein, which is a critical part of the virus’s structure and is relatively conserved across different RSV strains, thus increasing the vaccines effectiveness.

Question 4

F protein

Answer 4

This F protein mediates fusion of the viral membrane within a host cell membrane, therefore targeting it would prevent RSV from effectively entering human cells

Question 5

In addition

Answer 5

• To these two licensed vaccines, there are 24 others currently in the clinical stages of development, and are currently awaiting approval for use in Australia.
• An example is the mRESVIA vaccine which is in use in America, however its not as effective as the Arexvy or Abrysvo vaccines.

Question 6

Vaccine detail

Answer 6

• Going into a bit more detail about the vaccines, Arexvy is an adjuvanted bivalent vaccine, meaning it contains a substance that enhances the body’s immune response, is effective against both RSV A and B strains and it codes for a single prefusion F protein.
• Abrysvo, on the other hand, is unadjuvanted, but it is still bivalent and also targets the prefusion F protein.
• The main advantage of Abrysvo is that it provides passive immunity to newborns when administered to pregnant women.
• This maternal vaccination is essential as neither of these vaccines should be administered to infants or children due to the possibility of developing esophagitis or other severe diseases.

Question 7

Who can receive?

Answer 7

• In terms of who should receive these vaccines, they are mainly targeted for all people aged 75 or over
• Aboriginal and Torres Strait Islander people aged 60 and over
• People with medical risk factors for severe RSV disease aged 60 and over
• and pregnant women to protect their newborn infant.

Question 8

Effectiveness

Answer 8

• Both vaccines have shown impressive efficacy in adults, with 80-95% effectiveness,
• however Abrysvo has demonstrated a mere 56.8% effectiveness in newborns through maternal vaccination and therefore other pathways for prevention in this age group should be explored, such as the antibodies Rohan spoke about

Question 9

Conclude

Answer 9

• These vaccines represent significant advancements in our ability to prevent RSV, particularly for vulnerable populations like the elderly and pregnant woman.
• However, for infants, where maternal vaccination shows limited effectiveness, utilising antibodies as an alternative preventive measure offers a crucial path forward in ensuring comprehensive protection for all age groups.