For animal health pros born before 1990, antigenic drift and antigenic shift are not mere terms. Rather, they have been part of life experiences. Canine coronavirus, bovine viral diarrhea and equine herpes virus are among viruses our industry has chased with vaccines and vaccine updates. Rapid advancements in genotyping and mass spectrum technologies have been helpful as we faced the challenges of heterology versus homology.
We chose the following resources to consider in the context of Covid-19, its viral mutations and the ongoing challenges of getting ahead of the emerging viral complex.
Sources:
- How the flu virus can change: drift and shift, CDC. Link.
- School risk calculations scrambled by fast-spreading virus strains, Science, January 15, 2021. Link.
The new B.1.1.7 variant is up to 50% more infectious than previous variants.”
- New coronavirus variants could cause more reinfections*, require updated vaccines, Science, January 15, 2021. Link.
INSIGHTS: *I must admit the use of the term resistance in the context of viral vaccines disturbed me. After some digging, the pharmaceutical resistance parallel was addressed in the articles below. It will take more study for me to better understand vaccine resistance since my training moves me toward homology and heterology thinking when a vaccine fails to protect as expected.
Also see:
- Why the evolution of vaccine resistance is less of a concern than the evolution of drug resistance, NCBI, December 17, 2018. Link. Vaccines and antimicrobial drugs both impose strong selection for resistance. Yet only drug resistance is a major challenge for 21st century medicine. Why is drug resistance ubiquitous and not vaccine resistance? Part of the answer is that vaccine resistance is far less likely to evolve than drug resistance.
- Vaccination resistance has finally been explained, Health Europa, January 10, 2021. Link.
Once people question the safety or effectiveness of a vaccine it can be very difficult to get them to move beyond those negative associations. Hysteresis is a powerful force that is difficult to break at a societal level.” – Feng Fu