Just when we all thought that the new COVID-19 variants now circulating in the US from the UK (B.1.1.7) and South Africa (B.1.351) were our biggest concerns, there are now reports that a potential pandemic bird flu, H5N8, has jumped to humans—with seven cases reported in Russia at the time of this writing. H5N8 is highly pathogenic in poultry but was never previously seen in humans. It is important to acknowledge that poultry-to-human spread is the first of two steps in which we may experience yet another novel influenza virus that could easily cause a global pandemic. The second step—human-to-human spread—has not been documented thus far. But persons, or birds, infected concurrently with H5N8 and with a strain of influenza that is spread human-to-human could allow H5N8 to mutate. The consequences of this happening would be devastating.
Since being called out in an Emerging Infectious Diseases article published by the CDC in 2017, this novel H5N8 influenza has been reported in migratory birds in Russia, Asia, Europe, and Africa. While not ubiquitous, it is not rare.
There is a great deal to worry about with this announcement. We have a sense of what could happen from accounts of the influenza pandemic of 1918 that killed at least 50 million worldwide. And we better understand from COVID-19 what the introduction of a novel respiratory virus can do.
The good news is that, through the Pfizer and Moderna mRNA technologies that were utilized in developing the COVID-19 vaccines, we now have the technology to develop a prototype vaccine in less than 2 weeks after genomic sequencing of a virus, including an influenza virus. This dramatically trims development time compared to previous technologies. Further, because mRNA is now a proven technology, and the vaccine to be developed would be a flu vaccine, it likely would not require rigorous clinical trials as the COVID-19 vaccines did.
We need to remember, however, that this does not imply that we can churn out hundreds of millions of vaccine doses in a short period of time, especially when current manufacturing capabilities are operating at 100% of capacity to tackle COVID-19.
It would do well to keep track of new developments with H5N8, as it is a rapidly developing story with the potential to escalate with a single mutation.