Bovine Mycoplasma vaccines and immune responses

23 March 2022

The International Veterinary Vaccinology Network (IVVN) and the United States Animal Vaccine Research Coordination Network (USAVRCN) hosted a joint webinar on bovine Mycoplasma vaccines and immune responses.

The webinar comprised presentations from three invited speakers, a panel discussion, and a Q&A session with participants. The event was chaired by IVVN Network Management Board Member Professor Brian Perry and Director of USAVRCN, Professor Steve Geary.

Please note that the recording's captions have been generated automatically and may not be fully accurate.

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Questions and answers

During the session, attendees asked questions to the speakers. Some of these were answered live, and you can listen to these answers in the recording above. Others were answered in writing – these answers are shown below.

Question from Tyler Gavitt

Do we know the actual attenuation profile of BEN-1 and its deriviative vaccine strains? Is CPS expression one of the compromised/attenuated behaviors of these vaccines, or could we use our knowledge of these specific attenuations to design safer vaccines?

Answer from Joerg Jores: In the absence of a good challenge model, the fine tuning in terms of attenuation levels is arther difficult, you can consult these papers: PMID: 26750304 and PMID: 21439870

Question from totte

Your work in vivo showed that mycoplasmas lacking CPS are avirulent but also not capable of inducing protective immunity most likely due to quick elimination by the host. How will you prevent that in further prototype vaccines based on CPS?

Answer from Joerg Jores: The challenge dose was very high, therefore I am careful in excluding protective capacity of the CPS deficient strain. Moreover, a glycocongugated vaccine might be tried.

Question from Tyler Gavitt

How predictive are serum Ab titers against M. mycoides of protection against infection at the surface of the lung? I know that in the context of M. gallisepticum and M. pneumoniae, it can be difficult to draw conclusions about protection at the lung surface from circulating antibody titers.

Answer from Joerg Jores: In the absence of a good challenge model, the fine tuning in terms of attenuation levels is rather difficult, you can consult these papers: PMID: 26750304 and PMID: 21439870, I agree with your statement about general measurement of circulating antibodies.

Question from Thomas Inzana

Is the "capsular polysaccharide" attached to the membrane, such as through a lipid anchor, or is it released from the cell ?

Answer from Joerg Jores: There are reports about both forms in Mmm EPS and CPS

Question from n.semmate

Dr joerg, what s your opinion about inactivated cbpp vaccines ?

Answer from Joerg Jores: contradicting papers were published in teh past, but in 2016 KALRO published a paper in VETIMM that shows protection levels similar to T1/44 live vaccine

Question from Tyler Gavitt

Can you please expand more on the analysis of IgG1 in the serum and BAL of vaccinated animals? Is IgG1 thought to be the antibody subclass necessary for protection from infection in these animals, or is it the subclass preferentially induced by exposure to M. bovis antigen?

Answer from Jose Perez-Casal: We don’t know if IgG1 and IgG2 are what we need. Both are induced, also IgA

Question from totte

you did not mention the cost of sub-unit vaccines that may prevent their use in low-income countries. Do you plan to work on that aspect for example to achieve protection after a single injection?

Answer from Joerg Jores: Please liaise with VIDO and KALRO scientists about that, since its their project and they can give the best answer. Costs are coming down and I can imagine that local governments might support such a vacciine roll out.

Question from Robert Valeris-Chacin

Dr. Perez-Casal, you mentioned a challenge with M. bovis and M. haemolytica, could you share if your group has studied more closely the impact on lesions/mortality if you challenge first with M. bovis and later with M. haemolytica and viceversa?

Answer from Jose Perez-Casal: No we have not