# What exactly is the cause of various covid waves/spikes in cases

**URL:** <https://boards.straightdope.com/t/what-exactly-is-the-cause-of-various-covid-waves-spikes-in-cases/947147>\
**Category:** The Quarantine Zone\
**Tags:** covid-quarantine\
**Created:** [July 23, 2021, 4:22pm UTC](https://boards.straightdope.com/t/what-exactly-is-the-cause-of-various-covid-waves-spikes-in-cases/947147 "2021-07-23T16:22:15Z")\
**Posts on this page:** 7\
**Page:** 1

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**Author:** ![Wesley\_Clark](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/wesley_clark/32/20581_2.png) [@Wesley\_Clark](https://boards.straightdope.com/u/Wesley_Clark)\
**Post date:** [July 23, 2021, 4:22pm UTC](https://boards.straightdope.com/t/what-exactly-is-the-cause-of-various-covid-waves-spikes-in-cases/947147/1 "2021-07-23T16:22:15Z")

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> **[Number of COVID cases in the U.S. per week 2022 | Statista](https://www.statista.com/statistics/1102816/coronavirus-covid19-cases-number-us-americans-by-day/)**
>
> There were 281,955 new COVID cases in the United States during the week ending Nov. 11, 2022. The number of COVID cases per day continues to fluctuate.

Looking at that, there’s been about 5 waves of covid in the US.

First one was when the virus first started, then it dipped (probably due to lockdowns).

Then it jumped again in July, then dipped again. Then it jumped dramatically around December/January, then started dropping again.

Another minor wave in April, then a dip, then it started jumping again in July.

So five crests and four troughs. What were the causes of each?

The fifth wave (the current one) I would assume is due to the rise of the Delta variant. First wave is just the first wave of the illness.

Was the third crest/wave due to family members getting together for the holidays in November and December.

Was the second crest people getting sick of lockdowns? Are the third and fourth troughs due to vaccinations?

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**Author:** ![Wesley\_Clark](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/wesley_clark/32/20581_2.png) [@Wesley\_Clark](https://boards.straightdope.com/u/Wesley_Clark)\
**Post date:** [July 23, 2021, 4:59pm UTC](https://boards.straightdope.com/t/what-exactly-is-the-cause-of-various-covid-waves-spikes-in-cases/947147/2 "2021-07-23T16:59:14Z")

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So for example, these are guesses but I would assume something like

First crest - the original virus makes its first appearance  
First trough - initial lockdowns  
Second crest - people get sick of lockdowns and start going out  
Second trough - ?  
Third crest - People engage in social activity around the holidays  
Third trough - vaccinations  
Fourth crest - ?  
Fourth trough - vaccinations  
Fifth crest - Delta variant appears in the US

I am guessing that may be the causes, does anyone know for sure?

When did easy testing become mainstream? When this first started in March of last year it was almost impossible to get a test. Now its extremely easy, but I’m not sure when the transition happened.

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**Author:** ![snowthx](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/snowthx/32/10660_2.png) [@snowthx](https://boards.straightdope.com/u/snowthx)\
**Post date:** [July 23, 2021, 5:12pm UTC](https://boards.straightdope.com/t/what-exactly-is-the-cause-of-various-covid-waves-spikes-in-cases/947147/3 "2021-07-23T17:12:12Z")

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> [@Wesley\_Clark](#):
>
> Fifth crest - Delta variant appears in the US

I cannot speak for all parts of the country, but in CA, the loosening of all restrictions in mid-June, plus the Delta variant circulating among the unvaccinated, seems to me the cause of the current spike, at least out west.

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**Author:** ![Tfletch1](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/tfletch1/32/5340_2.png) [@Tfletch1](https://boards.straightdope.com/u/Tfletch1)\
**Post date:** [July 23, 2021, 6:19pm UTC](https://boards.straightdope.com/t/what-exactly-is-the-cause-of-various-covid-waves-spikes-in-cases/947147/4 "2021-07-23T18:19:44Z")

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My comments **bolded**

> [@Wesley\_Clark](#):
>
> First crest - the original virus makes its first appearance  
> First trough - initial lockdowns  
> Second crest - people get sick of lockdowns and start going out - **reopenings in Southern states and some seasonality (southern states - too hot to be outside)**  
> Second trough - ? - **partial, targeted restrictions reimposed, behavior modification due to news reports**  
> Third crest - People engage in social activity around the holidays  
> Third trough - vaccinations - **and behavior modification AND some populations becoming immune**  
> Fourth crest - ? **- alpha variant and some schools/sports going in-person (Michigan, for example)**  
> Fourth trough - vaccinations  
> Fifth crest - Delta variant appears in the US

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**Author:** ![Banksiaman](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/banksiaman/32/3334_2.png) [@Banksiaman](https://boards.straightdope.com/u/Banksiaman)\
**Post date:** [July 23, 2021, 11:22pm UTC](https://boards.straightdope.com/t/what-exactly-is-the-cause-of-various-covid-waves-spikes-in-cases/947147/5 "2021-07-23T23:22:58Z")

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Also you need to factor in that this is a cumulative tally of what can be very different state experiences. And, because it is raw numbers, the effect of it going rife in a big state in Month X, versus an outbreak in much less populated East Dakota in Month Y tend to blur rather than sharpen the outline. New York’s curve for example is quite different and accounts for a lot of the first peak, while many states were almost flatlining.

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**Author:** ![asahi](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/asahi/32/8693_2.png) [@asahi](https://boards.straightdope.com/u/asahi)\
**Post date:** [July 24, 2021, 4:10am UTC](https://boards.straightdope.com/t/what-exactly-is-the-cause-of-various-covid-waves-spikes-in-cases/947147/6 "2021-07-24T04:10:53Z")

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There was the initial wave, which was then followed by a lot of lockdowns. The case numbers began to level off and people started thinking “We got this” and “I’ve been in my home for three months. I’m done with this lockdown crap - it’s just flu” and the numbers started a gradual rise. Then schools reopened. And then the holidays. Schools + holidays + Alpha variant = the worst wave yet.

Then we got the vaccines and it started going down - until we had a new variant. Now the numbers are going back up again.

The common thread is: pandemic fatigue → “Fuck restrictions” + new variant = lots of hospitalizations and deaths.

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**Author:** ![elfkin477](https://avatars.discourse-cdn.com/v4/letter/e/a9a28c/32.png) [@elfkin477](https://boards.straightdope.com/u/elfkin477)\
**Post date:** [July 24, 2021, 11:27pm UTC](https://boards.straightdope.com/t/what-exactly-is-the-cause-of-various-covid-waves-spikes-in-cases/947147/7 "2021-07-24T23:27:58Z")

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> [@asahi](#):
>
> Then we got the vaccines and it started going down - until we had a new variant. Now the numbers are going back up again.
> 
> The common thread is: pandemic fatigue → “Fuck restrictions” + new variant = lots of hospitalizations and deaths.

“Now that mask wearing isn’t enforced I’m gonna pwn the libs by pretending to be vaccinated and acting like I am **and having huge holiday gatherings** ” has to be part of the equation too. Delta’s been in the US months, lots of states dropped mandates going on 2 months ago - it’s not a coincidence that the numbers spiked shortly after a major summer holiday.
