"Dangerous New Variants" & Global Vaccination Coverage
Why vaccinating 100% of the world doesn't signal the end of anything...but there's hope.
From Oxford Languages:
It’s Almost a Chant Now
Ever since vaccine companies started pumping out vials of the good stuff in high volumes in 2021, we’ve heard the multitudes of epidemiologists and public-health experts state some version of this line in just about every article or tweet that mentions COVID-19 vaccine equity or viral mutations:
We need to deliver more vaccines to the rest of the world to stop the emergence of dangerous new viral variants that could evade our immunity.
It’s a laudable goal, and we should definitely pursue a goal of immunizing the world against COVID-19. It has this rather cool effect of keeping people alive, mostly out of the hospital, and mostly healthy. I mean, don’t ask me, ask Dr. Eric Topol of Scripps Research:
But we could vaccinate 100% of humans on Earth (and even those in space) with 3 shots each, erase “anti-vax” from the dictionary in all world languages, and we won’t be able to stop viral mutations of SARS-CoV-2.
Huh?
SARS-CoV-2 Can Infect Your Cat
All 7 of the known coronaviruses in circulation among humans (HCoVs) today are zoonotic, meaning that animals passed them to humans. Humans can also pass them back to animals. According to the NIH:
All seven HCoVs have a zoonotic origin from bats, mice or domestic animals. Multiple lines of evidence support an evolutionary origin of all HCoVs from bats, where viruses are well adapted and non-pathogenic but show great genetic diversity.
Why is this important? Well, as long as there are humans and animals together on Earth, SARS-CoV-2 will have hosts, which means it isn’t going to go away.
Ever.
After all, the leading theory is that a bat passed the SARS-CoV-2 virus to humans in Wuhan. And here’s a story about a tiger that contracted the virus. As stated above, all of them originated with animals and passed onto humans.
So, unless the quote above is changed to something like this…
We need to administer vaccines to all animals of world capable of hosting the SARS-CoV-2 virus to stop the emergence of dangerous new viral variants that could evade our immunity.
…there will be a SARS-CoV-2 virus, it will pass from host to host - human or not - it will continue to mutate, and some of those mutations will improve their immunity-evading capabilities over time.
Full stop.
“But Smallpox, Jeff!”
Smallpox isn’t a zoonotic virus. Vaccinate all the humans and it goes away.
No Vaccine is Perfect, and Vaccines Generally Can’t Stop Infections
This should go without saying, but I’ll say it again. We’ve been spoiled by mRNA vaccines that turned out to be successful moon shots. This set an unreasonable expectation that we’d somehow eradicate the disease. For history on vaccines targeting respiratory diseases, however, here are estimates of real-world flu-vaccine effectiveness from the recent past:
This is what Dr. Fauci and the FDA were anticipating when Pfizer & Moderna turned in their data, not the 90-95% efficacy (in trials) and the observed ~75-80% effectiveness in real life that they got. So, we got spoiled.
Does this mean that flu vaccines don’t work? Nope. They work just fine, and you should get yours. But the the fact that you’re encouraged to get a flu shot that might be able to keep you from getting sick only 25-50% of the time illustrates the fact that vaccines are meant to prevent severe illness (you getting really sick) and worse outcomes. They’re meant to keep the hospitals and morgues running at regular (and not surge) capacity, not to keep Walgreens from running out of Kleenex.
On top of this, you need to think about the physics and biology of viral infection. You’re breathing in the virus anytime you’re near a contagious person. Since your immune system is inside your body and vaccines prepare your immune system for the possibility of an invader (e.g.: the influenza virus), your immune system is reactive, not proactive. It sees a virus and attacks it. So if this is the normal scenario, how would your immune system stop a pathogen from entering your body and infecting cells?
It can’t. It just puts out the fire once it starts, which is better than not being able to put out the fire. This is why you get vaccinated.
Viruses Mutate, and Sometimes They Can Escape Your Immunity…Sort of
It’s just how it works.
Viruses are living organisms, albeit stupid, parasitic ones. They’re just tiny, sneaky bastards that are sloppy Xerox machines that keep shapeshifting and daring other organisms to find ways to locate and kill them. Over time, immune cells of various types find ways to kill off most viral particles and infected cells. However, some small percentage live to fight another day, and they do so by having some characteristic(s) change ever-so-slightly or “select” for immune evasion. One mutation tends to evolve from another, and the “drift” gets mapped in a “ladder” pattern. Stolen from Your Local Epidemiologist:
This is common when you have your average virus floating around a species. Virus mutates, immune system adapts, virus mutates, immune system adapts. Rinse, repeat.
But what happens if your virus can float around more than one species but you’re only sequencing viral genomes for one such species (e.g.: humans) and tracking them around the globe? Some freakin’ rando, long-lost cousin shows up out of nowhere and wants to join you for Thanksgiving, that’s what.
One leading theory of where Omicron came from is that there was a latent infection in a single immunocompromised person that harbored an old viral infection for a really long time until it mutated and got away from that person’s feeble immune system. That could explain why it was hidden for over a year.
The other leading theory is that a virus from the Alpha lineage skipped back to animals and those animals passed around the virus for over year, allowing it to mutate a bunch, after which it skipped back to humans as Omicron. That’s how we missed its evolution - it was mutating in sheep or feral cats or whatever.
Note that, in both of these leading theories…
We need to deliver more vaccines to the rest of the world to stop the emergence of dangerous new viral variants that could evade our immunity.
…wouldn’t have stopped the emergence of Omicron.
The immunocompromised person may have been fully vaccinated and, since vaccination can’t stop infection, the vaccine wouldn’t have stopped its mutation.
We aren’t vaccinating sheep, cats, bats, dogs, etc.
SARS-CoV-2 is Now an Endemic Human Coronavirus
So, we have the following truths about SARS-CoV-2:
The virus can spread among humans
The virus can spread among animals
Vaccines can’t stop infection
Vaccines and prior infection provide some level of immune response (varies from person to person) that mute severe impacts of the COVID-19 disease that arise from SARS-CoV-2, making it a manageable disease
We’re not vaccinating animals
This means that SARS-CoV-2 is going to circulate forever, make us sick sometimes, and it’s possible that public-health authorities will recommend regular booster shots in the same manner they do flu shots going forward. So, COVID-19 isn’t going to disappear, but it’ll likely just be like a bad cold for most of us.
Choose Your Risk Level
In the Before Times, there were people that didn’t care about getting sick and then there were people with hand sanitizer and Kleenex on speed dial. I’d imaging this pandemic has affected this behavior, too. I fully expect all public-health mandates to be rescinded in the coming few months. However, I’m pretty sure that we’re likely to see these behavior changes going forward:
Better vaccination compliance
Some people choosing to wear masks in crowded spaces
KF94s and KN95 masks regularly sold in grocery stores, online, and in pharmacies
Fewer people attending work or school when sick
People and organizations will choose their risk levels, and that’s OK.
There’s Reason to be Optimistic About Future Infections
Don’t want to get all kinds of shots? Well, there’s hope :) There are at least 3 entities that are developing combination shots:
Moderna is developing a vaccine that would target, SARS-CoV-2, influenza, and respiratory syncytial virus (RSV).
Novavax is developing a shot for SARS-CoV-2 and influenza.
The US Army is developing a pan-SARS vaccine that would target both SARS-CoV-1 and -2.
Given that there isn’t currently a vaccine against RSV and that targets young children, the Moderna one sounds pretty cool. But there’s a lot of work going into these vaccines right now and that should make cold & flu season more manageable for everyone in the future.
We could all use a little optimism, #amirite?