Can We Predict How Long Vaccines Last?

Hello, Summarians!

This newsletter is an attempt to help us all cope with the deluge of information we face every day. It usually contains 3 summaries and citations related to animal health.

Today I’ve included an intriguing discovery about how our immune system works. How can it be that 1 vaccine can last a lifetime and another needs to be bolstered every couple of years? This study gives us some tantalizing clues.

Please give me feedback on how I can make it more useful.

If it is valuable to you, please consider sending it on to a friend 😄 

Cruciate Rupture in Labs

Retrievers, a breed particularly predisposed to CR with a prevalence of 5.79%, the disease shows high heritability, with estimates ranging from 0.54 to 0.89. A genetic risk test, developed using a reference population of Labrador Retrievers, demonstrated approximately 98% accuracy using a posterior probability threshold of greater than 0.5, although the multifactorial nature of CR means that environmental factors still play a role. 

The objective of the study was to explore which environmental factors might contribute to the development of CR in dogs whose clinical presentation did not match their predicted genetic risk. By focusing on Labrador Retrievers with discordant genetic risk scores—those that developed CR despite low genetic risk or remained healthy despite high genetic risk—the researchers evaluated variables such as neuter status, age of neutering, height, weight, body mass index (BMI), and athletic activity. The findings revealed that neutering before 12 months of age significantly increased the risk of CR, whereas overall neuter status, neutering before 6 months, body size measurements, and levels of athletic activity were not significant risk factors. These results support previous observations that while neutering at a younger age may influence CR risk, the overall impact of neutering varies depending on the breed and other factors. 

The study also notes that differences in outcomes across various investigations could be due to the heterogeneous nature of CR and the specific demographics of the populations studied. Limitations such as a relatively small sample size and reliance on owner-reported data were acknowledged, and it was emphasized that these results may not be directly applicable to other breeds due to the high genetic heterogeneity observed across canine populations. Ultimately, the research underscores the dominant role of genetics in CR development in Labrador Retrievers while identifying early neutering as a modifiable environmental risk factor that could help inform strategies for managing CR risk in this breed. 

DeForge, T. L., Momen, M., Conidi, G., Muir, P., & Sample, S. J. (2025). Age of neutering contributes to risk of cruciate ligament rupture in Labrador Retrievers. Journal of the American Veterinary Medical Association, 263(3), 31 https://doi.org/10.2460/javma.24.06.0406 

Bottom line — Wait until 12 months of age.

Estimating Vaccine Durability

The study used systems vaccinology to analyze immune responses to an H5N1 influenza vaccine—with and without the AS03 adjuvant—and found that a platelet and adhesion-related transcriptional signature present on day 7 could predict the longevity of the antibody response. This finding suggests that platelets, which originate from megakaryocytes, may play an important role in modulating long-term antibody durability. To investigate this further, the researchers examined the effects of thrombopoietin (TPO)-mediated megakaryocyte activation, discovering that TPO administration enhanced the durability of vaccine-induced antibodies. They also found that TPO-activated megakaryocytes support the survival of human bone-marrow plasma cells via integrin β1/β2-mediated cell-cell interactions, in addition to involving survival factors such as APRIL and the MIF-CD74 axis. Furthermore, by applying machine learning, they developed a classifier based on the platelet-associated signature that successfully predicted antibody longevity across six different vaccines in seven independent trials, pointing to a conserved mechanism of vaccine durability. 

Cortese M, Hagan T, Rouphael N, Wu SY, Xie X, Kazmin D, Wimmers F, Gupta S, van der Most R, Coccia M, Aranuchalam PS, Nakaya HI, Wang Y, Coyle E, Horiuchi S, Wu H, Bower M, Mehta A, Gunthel C, Bosinger SE, Kotliarov Y, Cheung F, Schwartzberg PL, Germain RN, Tsang J, Li S, Albrecht R, Ueno H, Subramaniam S, Mulligan MJ, Khurana S, Golding H, Pulendran B. System vaccinology analysis of predictors and mechanisms of antibody response durability to multiple vaccines in humans. Nat Immunol. 2025 Jan;26(1):116-130. doi: 10.1038/s41590-024-02036-z. Epub 2025 Jan 2. PMID: 39747435. 

Bottom line — We may be able to predict the duration of immunity much more accurately.

3-D Tissue Culture in Horses

The text outlines the evolution of preclinical testing from simple monolayer cell cultures to more advanced three-dimensional explant systems that better mimic the in vivo environment of tissues. It explains that while cartilage research has benefited from such innovations, joint disease treatment still faces challenges, particularly in understanding and supporting synovial function. The study described aimed to validate a short-term, three-dimensional equine synovial explant culture system. By using tethered 6‐mm explants maintained over a four‐day period, the researchers demonstrated that this system preserves tissue viability, secretory functions, and metabolic integrity. They detailed methods for consistent tissue perfusion, viability assessment using established staining techniques, and evaluations of cytokine secretion, which mirrored in vivo inflammatory responses. Additionally, the metabolic profiling of key enzymes provided insights into the tissue’s homeostatic and inflammatory pathways. Overall, the work establishes a reliable ex vivo model that can potentially bridge critical gaps in synovial biology, offering a more physiologically relevant platform for testing therapeutics aimed at mitigating joint degeneration. 

Arnade, H., Ivie, I. E., Gordon, J., & Peroni, J. F. (2025). Three-dimensional tissue culture supports the structure and function of equine synovial explants over 4 days. American Journal of Veterinary Research https://doi.org/10.2460/ajvr.24.11.0357 

Bottom line — May aid in developing drugs safer and faster.

Just putting things in perspective …