7/7 Finally to thank everyone who worked so hard to get this paper published from @researchleeds.bsky.social @ox.ac.uk (STRUBI) @NIBSC_MHRA and @ukcpi.bsky.social and if anyone has any questions then please let us know!

6/7 These results highlighted that our PV VLPs have the potential to be produced using currently available infrastructure making them a viable next-generation vaccine candidate for a polio-free world #Endpolio #vaccineswork

5/7 Then for the first time, we showed that in the presence of adjuvant, a trivalent immunisation of our VLPs were as immunogenic in the vaccine batch release assay as the current IPV vaccine showing the potenital for dose-sparing #endpolio #vaccines

4/7 Despite this similarity, this new PV2 VLP displayed increased increased immunogenicity compared to its predecessor, and in the presence of adjuvant was as immunogenic as the current IPV vaccine

3/7 We also produced a different PV2 mutant, which significantly increased VLP yields and improved particle thermostability. The team @ox.ac.uk (STRUBI) then determined the structure of these mutants by cryoEM and found them to be highly similar

2/7 This paper follows on from our previous work, highlighting how immunogenic poliovirus virus-like particles (PV VLPs) made in yeast can be made at scale using fermentation with increased yields compared to flask-based expression

8/8 Finally, I just wanted to thank all members of the consortium for their hard work in getting this over the line at @researchleeds.bsky.social @ox.ac.uk (STRUBI) @NIBSC_MHRA @johninnescentre.bsky.social and if anyone has any questions or wants to know more, then please let us know!

7/ These results highlighted that these VLPs have the potential to be used as a next-generation poliovirus vaccine post-eradication to avoid the problems posed by using live virus to produce our current vaccines. #Vaccineswork #Endpolio

6/ So we took inspiration from other VLP vaccines and used an adjuvant, which worked beautifully! With VLPs for all three poliovirus serotypes being more or as immunogenic as IPV in the rat model!

5/ Finally, we wanted to test these VLPs using the vaccine batch release assay. Interestingly, in contrast to the mouse model, our initial tests showed that the VLPs were not as immunogenic as IPV in the rat model . . .

4/ We then needed to determine if these VLPs were immunogenic. The team at NIBSC-MHRA Vaccine Division assessed how well these VLPs induced neutralising antibodies in comparison to the current vaccine (IPV), using a mouse model, highlighting that all the VLPs tested were as immunogenic as IPV

3/ The team @ox.ac.uk (STRUBI) then analysed the VLPs produced from each expression system by cryo-EM to ensure that these particles have the correct conformation and maintain the known immune epitopes present on infectious virions

2/ Naturally occurring empty capsids undergo a conformational change meaning that they no longer produce a long-lasting immune response. Therefore, our consortium have identified a number of mutations which maintains the D Ag conformation which induces long-lasting immunity