Currently, there is no hard evidence that proves COVID-19 spreads more effectively in the colder months. There is, however, some possible evidence that is merely inconclusive. The only way to know with any certainty is to wind back the clock and reexamine what happened and why.
The COVID-19 outbreak began in China in late December, though Patient Zero was likely infected early December/late November. The virus likely first appeared in animals in mid or late autumn. As the virus became more prevalent in animals, infection became increasingly likely.
After Patient Zero is infected, a few more people are infected. A few weeks later, the Seafood Market Outbreak occurs, drawing more and more attention to the virus. This is the first time we hear about some kind of unknown viral pneumonia.
However, given the rapid timeframe in which China was able to sequence the genome of the SARS-CoV-2 virus, I’m willing to bet that they knew they were dealing with some kind of disease (one of Patient Zero’s contacts) and were already in the process of sequencing it.
For the record, I’m not saying China knowingly hid a dangerous virus from us. They likely started sequencing the virus before the Seafood Market Outbreak, knowing it was novel virus, but not knowing what they were dealing with.
It could’ve been anything. There are a number of respiratory viruses, from Coronaviridae to Orthomyxoviridae to Paramyxoviridae and beyond. I’ve just named three families of viruses, each with their own genuses, species, lineages, strains, etc.
In those three families alone are dozens of distinct viruses. And, it could’ve been a virus outside of these families. Maybe it’s not a respiratory disease, but the disease merely involves the lungs.
Ebola Virus Disease isn’t a respiratory disease, nor is HIV, but they both have flu-like symptoms in the beginning. Hell, China has had a history with Hantavirus. What if it’s Hantavirus? As this unreasonably long tangent illustrates, finding a novel virus can be hard work.
So, Patient Zero (or one of their contacts) goes to the doctor with some kind of bad illness. First things first: rule out the most likely causes. The doctor checks out the patient, and rules out many of the Paramyxoviridae along with most of the Coronaviridae.
Oh, I forgot to add Picornaviridae, the family of viruses that includes Rhinoviruses. Rhinoviruses are the cause of roughly 70% of common colds. So, the doctor says they want to hear from their patient at a later time.
This is likely happening with many different patients at roughly the same time. As time goes on and tests are conducted, many of the more severe diseases are ruled out, followed by Picornaviridae and Orthomyxoviridae. Antibiotics aren’t working.
BTW, Orthomyxoviridae are the family of viruses that include influenza viruses. At this point, fungal and bacterial infections are ruled out. The patient likely gets some imagery and bloodwork done, and the results rule out everything except an infection.
Oh, and as for those who want to know about Paramyxoviridae, it’s not something I want to get into on Twitter. It’s such a diverse family and Twitter is not a place for long descriptions. I’m already on a huge tangent as it is. You’re better off looking it up.
Anyways, the doctor(s) decide the time is right to sequence the genome of whatever kind of virus they’re trying to fight. Any possibility of a novel influenza is tossed out. Genetic sequencing will take some time. In that time, the Seafood Market Outbreak occurs.
Based on the timeline, it is likely that China knew they were dealing with a novel Coronavirus, but stuck with the “unknown viral pneumonia” phrasing, as they likely didn’t know from what genus of Coronaviridae came this particular virus. However, now the whole world is watching.
China was going to have to report something, even if it was nothing serious. Any hope of this novel virus just going away without a trace is gone. The news was going to spread, even if the virus didn’t. So, they report that an unknown viral pneumonia has caused an outbreak.
Soon afterwards, the virus was given the name nCoV-2019. It is confirmed to be a Betacoronavirus. According to JHU, results from a Shanghai lab published on January 4th show nCoV-2019 to be a Sarbecovirus, meaning it belongs to the same lineage as SARS-CoV, Lineage B.
According to JHU, China officially announced nCoV-2019 to be a novel Coronavirus on January 7th, 2020. At this point, the world was finally alerted to a virus that likely infected the first patient a month before anyone outside of China even knew it existed.
In an earlier tweet on this thread, I said it was soon after the Seafood Market Outbreak that the novel virus nCoV-2019 was given its name. While technically true, the way I structured this information in this thread may have been misleading.
Some people who read this might’ve thought that I was saying nCoV-2019 was given its name before January 4, 2020, the date JHU says the Shanghai lab found the virus to be a Sarbecovirus. However, that was not my intent.
Now, at this point, this new disease would’ve reached Phase 3 of WHO’s Pandemic Phases. Phase 3 means the virus has caused sporadic clusters of disease in humans, but there’s no conclusive proof of sustainable human-to-human transmission at a community level.
Now, this is the part that conspiracy theorists and critics of the WHO point at and say that the WHO covered this all up. However, the exponential base remained fairly low until around January 17th. January 17th was when the outbreak had the Law of Large Numbers on its side.
So, up until the end January 17th, a sustainable rate of human-to-human transmission wasn’t proven. Sure, the WHO could’ve sounded the alarm on January 17th, but let’s look at their options for a moment.
They could’ve sounded the alarm first thing on January 18th, sending the world into a panicked frenzy. However, this would’ve been a bad option. There was alarmism with Swine Flu, MERS, and the 2014 Ebola Outbreak.
Plus, the WHO was getting most of its funding from the U.S. The president had already pulled the U.S. out of the Paris Climate Accords and the Iran Nuclear Deal, and has expressed his resentment towards the U.N., which runs WHO.
Prematurely sounding the alarm for something that ultimately fizzled out would surely cost the WHO. The U.S. would cut all funding for the WHO. If the WHO waited until there was conclusive proof of sustained human-to-human transmission, then alarmism may be preventable.
Waiting until there was conclusive proof of human-to-human transmission was the safest, most humane, and most scientific way to approach it. Panic and fear breeds irrationality. Waiting for conclusive proof was the right thing to do, no matter how you look at it.
After all, January 17th could’ve been a simple anomaly. The upward trend of the exponential base number was simply too new to confirm anything. It was on January 19th that the true base number could finally be nailed down with any certainty.
Sure enough, on January 20th, human-to-human transmission was confirmed by China, putting this new disease at Phase 4. Phase 4 means that a sustainable rate of human-to-human transmission is occurring at a community level.
Back when it was at Phase 3, it was under 200 cases. Other Phase 3 diseases include Nipah Virus Disease and MERS, neither of which are capable of becoming pandemics (at least to our knowledge).
NVD and MERS are horrific illnesses. In fact, NVD has a mortality rate on par with that of Ebola and smallpox, has a variety of hosts, and can spread in many ways. However, it does not make headlines here in the U.S., as it doesn’t spread at sustainable rates.
Oh, and there’s no vaccine for NVD. The only treatment protocol is supportive, much like Ebola in the early days of the 2014 outbreak. For these reasons, the WHO has made NVD a top priority. NVD is also the reason why I think the WHO should actually get even more funding.
Anyways, according to JHU, it was on January 13th that the maximum incubation period was determined to be 14 days. By January 20th, we were on Phase 4. This was significant. SARS, like EVD, doesn’t spread presymptomatically nor asymptomatically, so we were able to stop it.
But, if nCoV-2019 could readily spread before the onset of symptoms, then it would be much harder to contain. The flu spreads presymptomatically and asymptomatically, which is why Influenza pandemics are basically impossible to stop once they get going.
Worse still, if nCoV-2019 does spread presymptomatically, it could actually be much harder to stop than Influenza, since Influenza has a much shorter presymptomatic incubation period. A few days after January 20th, presymptomatic spreading was confirmed.
This was significant, as the controllability of this outbreak basically came down to how efficiently the virus was able to spread before symptoms showed up. It was also around this time that this new disease spread to other countries in the same WHO region.
At this point, if sustained human-to-human transmission was confirmed in these other countries, it would kick us up to Phase 5. Sadly, long before we could confirm a transition to Phase 5, the virus spread to countries in other WHO regions, putting us at risk of entering Phase 6.
Phase 5 alone basically means a pandemic is pretty much inevitable, and really only serves as an early-warning stage. Phase 6 is marked by sustained human-to-human transmission in multiple WHO regions. Phase 6 is also known as the Pandemic Phase.
Out of curiosity, I did go through some of my old texts to members of my family to see what my initial thoughts were. I do pretty much remember what was going on at the time, but it’s always interesting to look back on the Before Times.
The earliest documented evidence that I recognized the issue was back on January 26th, though I know I was concerned about the virus a few days before then. It was probably around January 19th, when confirmed cases surpassed 200. 200 sounded too high to not be communicable.
This would make sense, since it only surpassed 100 on January 18th. Interestingly enough, on January 26th, I stated that the mortality rate was 4%. That’s probably why the virus concerned me. In my naivety, I had believed that the 4% figure was indiscriminate.
In my defense, however, there wasn’t much data on age vs. mortality rate back in January, since there weren’t even 3,000 confirmed cases as of January 26th. I also find it interesting that I actually stated that international flights should’ve been banned by then.
But, most interestingly of all, it was clear that I was concerned about a potential pandemic. While I never explicitly stated my concern, the scenario I described on January 26th fits Phase 6, the Pandemic Phase.
I’m not claiming to be some kind of genius who saw this coming. I didn’t even know the WHO Pandemic Phases were a thing back then, nor did I know that the scenario I described technically fit the description of a pandemic. I had always imagined pandemics as much bigger.
However, it’s clear that I knew that we were going to meet the criteria to declare a pandemic, even if I didn’t exactly know what the criteria were. It is also clear that, based on the context, it was clear that I did think a pandemic was fairly likely.
On January 27th, the WHO said that the world’s risk was “high” in its 7th situation report. On January 30th, the WHO declared the nCoV-2019 a Public Health Emergency of International Concern (PHEIC).
Keep in mind that, while certain elements of Phases 5 and 6 were met, it couldn’t be proven that the criteria for Phases 5 and 6 had been met. So, all of this was happening while we were still in Phase 4.
Based on what I could gather from the WHO’s situation reports, I’d say the first conclusive proof of nCoV-2019 reaching Phase 5 was finally reached on February 5th. Incidentally, I also believe that this is also the first conclusive evidence that nCoV-2019 pushed us to Phase 6.
You may recall that Phase 6 is the Pandemic Phase. This is absolutely the case. Of course, those guidelines were developed in anticipation of an influenza pandemic. In my opinion, it doesn’t really matter.
Both illnesses are respiratory illnesses and, while they don’t have much in common from a virological point of view, they do have a lot in common from an epidemiological standpoint. So, I’d say February 5th was the day that the new disease caused by nCoV-2019 became a pandemic.
Of course, I have the benefit of hindsight. On February 11th, nCoV-2019 was renamed SARS-CoV-2, and the disease caused by this virus was given the name COVID-19. By this point in time, the virus was spreading exponentially, and not just in China.
I would like to add that, even without hindsight, it was pretty clear that the WHO waited too long to declare a pandemic. By February 26th, it became abundantly clear that Phase 6 criteria had been met. Italy had reported over 120 cases that came from within in its own borders.
By the way, this data came in on February 26th, so I know that they saw the same things I’m seeing now. At this point, avoiding alarmism would no longer be a valid excuse. The signs were glaringly obvious at that point.
On March 28th, the WHO releases their 39th situation report, which pegs the entire world as “high risk” of COVID-19. On March 11th, two weeks after February 26th, the WHO officially declared that the COVID-19 outbreak had grown to become a pandemic.
So, let’s try to find out what kind of epidemiological dynamics were at play. Some quick, yet reasonably accurate calculations put the initial R value at around 5. This was the value for China before they started their first round of restrictions. The R value then fell to 4.
As the outbreak continued throughout February, China cracked down even harder, essentially locking people inside their homes. Almost immediately afterwards, the growth number dropped dramatically, falling below 1 after less than a week.
Unfortunately, due to the nature of the data, it is simply impossible to determine what fraction of China’s victory comes from the intense response of the Chinese government and what fraction comes from voluntary, self-imposed restrictions the citizens placed upon themselves.
Either way, I have no difficulty believing that China was able to contain the virus and keep their numbers so low. China has had its tangles with respiratory diseases in the past, including SARS. In fact, SARS is probably the reason why COVID-19 didn’t have much of a chance.
The moment China realized that they could be overwhelmed by a highly contagious and deadly Sarbecovirus, I imagine they had every possible plan on the table. And China was absolutely brutal on its response. It’s pretty clear that China doesn’t like Sarbecoviruses.
In early March, as Italy’s COVID-19 situation heated up, things looked bad. My calculations peg Italy’s initial R value at somewhere between 4 and 6. It then began to fall as Italy put tight restrictions into place. The descent started slowly, but sped up as time went on.
In the U.S., there was fear. Many people were panicking. With the benefit of hindsight, the panic could be seen as unwarranted. However, at the time, we saw a virus with a 4% mortality rate kill thousands in China, and Italy was going down in flames.
Healthcare workers in Italy were pointing at the U.S. and telling us that we were seeing our future. A highly contagious and deadly Sarbecovirus had a gun to our head, and the ghosts of its previous victims were telling us that we would join them. We had every right to be afraid.
However, the R rate in America almost certainly remained below 3 all of the way up to March 11th, and restrictions in the U.S. remained fairly mild up until March. As it turns out, even moderate fear can keep a virus down far better than extreme government crackdowns.
And, while the fear was mostly an issue in March, there was fear in the U.S. long before then. In February, as China’s cases climbed into the tens of thousands, many people in the U.S. suffered from mild to moderate fear. The virus was already in the U.S., after all.
So, with America’s initial R number hanging around below the big ol’ 3, we didn’t really have the same issues as China and Italy, which both had initial R values of at least 4, most likely sitting somewhere around 5.
However, we had our first case over a week before Italy got theirs. Why didn’t our initial R value start higher up, even if it was for a brief period of time? Interestingly enough, the R value was actually even lower back before we were afraid of the virus.
So, why is this? Well, when dealing with such small numbers, it really comes down to a throw of the dice. When it comes to viral spread, the first couple of generations make all of the difference in terms of timing.
By the time the U.S.’s outbreak could qualify for the Law of Large Numbers, the fear had already started to settle in. For the next month, the virus would hobble along, slowly accumulating numbers.
But what does this mega-tangent have to do with how changes in the seasons affect COVID-19’s epidemiological dynamics, if seasonal effects even effect changes on the dynamics at all? The mega-tangent provides an informational background.
This informational background allows us to reason our way to the answer. Epidemiologically, we know that COVID-19 and influenza have a lot of things in common. Virologically speaking, they’re about as related as humans and lampreys. They’re not even in the same phylum.
So, we could look at Embecoviruses, the lineage of betacoronaviruses that includes some of the Coronaviridae that cause the common cold. There’re also alphacoronaviruses, some of which also cause the common cold. They’re all a part of the Coronaviridae family.
Well, at least we’re starting to keep it in the family. That’s a hell of a lot closer than a comparison with the flu. The common cold is also seasonal. However, those coronaviruses aren’t exactly novel, either. SARS-CoV-2 as we know it is, at most, just shy of a year old.
The other human coronaviruses have been around for a very long time. Only one of them may have actually caused a noteworthy pandemic. HCoV-OC43 is one of the suspects in the 1889-1890 Russian Flu Pandemic.
A coronavirus being mistaken for the flu, but how could this be? You wouldn’t mistake a human for a lamprey, why would one mistake a coronavirus and the flu? Well, it wasn’t really something people even tried to look into. Flu-like symptoms means flu, plain and simple.
Even if HCoV-OC43 was the virus behind the 1889 pandemic, it killed people in the summertime, suggesting that it might not have become totally seasonal until after it became endemic to the human population. Unfortunately, looking to the 1889 pandemic isn’t very helpful.
The role of seasonal changes in the 1889 pandemic is kind of ambiguous. It seems to suggest the possibility that seasonal changes have an effect, but it’s not exactly clear. Worse still, HCoV-OC43 is in the Embecovirus lineage, not the Sarbecovirus lineage.
So much for an appeal to virology. Given the lack of historical precedents, all we have to go off of is our own pandemic. Luckily, it’s August. We have nearly five seasons to look through, three in the Northern Hemisphere and two in the Southern Hemisphere.
Now, this thread has gone on for quite some time, pretty much all day, as a matter of fact! So, when can you expect your answer? I actually have the same question. I don’t yet know how the seasons will mess with COVID-19’s epidemiological dynamics. That’s why this thread exists.
This thread exists to provide information, and to figure out the answer to our question. Welcome to my thought process...or one of them, at least. Tomorrow’s portion of this thread will deal with the period between March 11th and the beginning of meteorological summer, June 1st.
COVID-19 is seasonal. There’s your answer. Effects-to-Cause Reasoning and Residual Reasoning brings you to only a few possibilities. Inductive Reasoning crosses off a few more. Syllogistic Reasoning, Systemic Reasoning, and Deductive Reasoning brings you to only one conclusion.
That conclusion is that COVID-19 is a seasonal virus. Of course, one could say that what we’re seeing right now is proof that COVID-19 is seasonal. It is not proof. It’s not even evidence. It’s an observation. We all know that lightning strikes twice, but does it strike thrice?
Yes, lightning can strike thrice. It can be entirely coincidental. It doesn’t necessarily mean anything. The same goes for these waves. COVID-19 can, will, and does surge in places that still contain large percentages of susceptible people.
It can surge quickly, making it appear as if it’s seasonal. However, the U.S. had a summer resurgence. that’s definitely not seasonal behavior. But this is also a pandemic. The virus is still fairly new in humans. Observations alone won’t get us anywhere.
And that’s why reasoning this stuff out is so important. While I didn’t finish my reasoning in this thread as I had intended, I did finish my reasoning. I just didn’t do it here. There is only one possibility: COVID-19 is seasonal.
You can follow @Ginteger.
Tip: mention @twtextapp on a Twitter thread with the keyword “unroll” to get a link to it.

Latest Threads Unrolled: