How a potential bird flu pandemic with human to human transmission would differ drastically from the COVID-19 pandemic

So the bird flu as a topic of discussion has come up pretty frequently in this sub given the recent news about the first H5N1 death reported in the US. The CDC studied the available information about the Louisiana patient who died and has assessed that the risk to the general public remains low, and they’re right, given that H5N1 is still a zoonotic infection. But they also highlighted that the most important part was that no human to human transmission spread has been identified so far.

Now, the biggest chance for H5N1 to mutate enough to achieve human to human transmission would be if someone were to be infected with H5N1 (bird flu) and the influenza (seasonal flu) virus at the same time. Something called genetic reassortment could occur; both virus’ segmented genomes would allow it to exchange genetic material with its host cells. This exchange could lead to the creation of a new virus that combines segments from both viruses. You could then end up with a virus that has the virulence of H5N1 and the human to human transmissibility of the seasonal flu, which would be a VERY dangerous strain indeed.

So let’s talk about how this hypothetical H5N1 pandemic would make the COVID-19 pandemic look like a walk in the park:

High mortality rate

  • H5N1 has a very high mortality rate in humans, around 50-60% in reported cases compared to COVID-19’s 1-2% mortality rate (this of course varies across age, health, and other factors).

Lack of immunity in humans

  • Unlike COVID-19, which is a coronavirus that humans have had some previous exposure to due to other coronavirus strains (and even then, vaccination was still very important), H5N1 is an avian influenza virus with little to no pre-existing immunity in the human population. This means that a mutated H5N1 virus could spread more rapidly and affect a larger portion of the population.

Severe disease presentation

  • H5N1 infections in humans tend to cause severe respiratory illness like ARDS (acute respiratory distress syndrome), which can lead to respiratory failure. COVID-19, while also capable of producing severe respiratory illness, especially in the elderly and immunocompromised, generally causes a broader range of symptoms, including many mild or asymptomatic cases. H5N1, with human to human transmission, might cause more severe disease in a greater population of individuals.

Limited medical preparedness

  • There is no widely available, effective vaccine for whatever this new strain of H5N1 would be. Research is ongoing yes, but the production and distribution of a new vaccine takes time, as we saw in the COVID-19 pandemic. There are already available vaccines for bird flu and H5N1 in its current state, but we can’t assume that these vaccines would still work if a potential genetic reassortment between H5N1 and the seasonal flu would occur.

Global impact and economic disruption

  • Given the high mortality and potential for severe disease, H5N1 with human to human transmission would absolutely overwhelm healthcare systems around the world. I personally know several doctors and other healthcare workers who have said that when the next pandemic hits, they’re out. They’d already been through enough with COVID; an H5N1 pandemic would make it seem like a cakewalk in comparison. And my country handled the pandemic relatively well compared to the US, so I can’t even imagine how American healthcare workers must feel.

  • Unlike COVID-19, which generally spared younger populations, an H5N1 pandemic would have a much broader demographic impact, putting an immense strain on both the healthcare system and the economy.

And that is precisely why the WHO, CDC, and well, most people with a background in medical science like myself view a potential H5N1 pandemic as an absolute nightmare scenario. But as scary as all that sounds, having recently gone through a previous pandemic means we already know what needs to be done if H5N1 does become the next pandemic. Stay home, wear a mask when leaving the house, practice social distancing, wash your hands regularly, and make sure to drink lots of vitamins and get enough sleep to boost your immune system. And this should be a given for this sub, but have enough food, emergency, and medical supplies at home to last at least half a year.