First a disclaimer before everyone yells at me, which keeps happening when I bring up herd immunity:
Herd immunity is not a dirty word. It is a scientific phenomenon. Data are what data are, to quote Professor Richard Hume, my college molecular neurobiology professor at Umich. You can blame him as he is the reason that I decided to do a neuroscience PhD, which eventually led me down the winding path that brought me to writing this blog post. Sorry Dr. Hume. I am not talking about this because I am a republican or a democrat. I am not trying to convince people to not wear masks or social distance (please still do those things, they work). I am bringing this up because information is power. It’s power to make more intelligent decisions about our own personal lives and about policy. I am also bring this up because it’s interesting. Whether there is herd immunity or not is basically the trillion dollar question in this whole pandemic. It speaks to how long this will last, whether vaccines will work, and how much more torture we all have to endure.
Ok so back to it.
I am going to start with the states hit hardest before we shut down (or sort of shut down), New York and New Jersey. These states have not seen a second wave, which btw, is a misnomer, it’s really a continuation of the first wave that got interrupted. The Hopkins dashboard map has states color coded by redder (increasing), white (stable), and green (decreasing).
I believe the reason that NY and NJ are not increasing, is that they achieved herd immunity before the shut down. I have been saying this for a long time now. A few months ago I said “let’s do a science experiment- if NY has herd immunity cases won’t go up with reopening”. Well here are the results- NY, not going up. There really is no other explanation I can think of for this besides herd immunity. New York City has not somehow become less populous. And neither state is being super careful. I have been to both of them in the last month. Jersey shore has packed beaches with very few people wearing masks. The below pic is from May 16th 2020 in Ocean City, NJ. So being really vigilant at social distancing and mask wearing is NOT the reason their numbers are staying low.
Here is a detailed view of New York’s daily new cases, which peaked on April 9th, descended to a crawl, and haven’t increased since.
Next, let’s take a look at the States that have had a sharp second peak after reopening, Texas, Florida, Arizona, and Louisiana. After a huge increase in cases post reopening, these states now have decreasing numbers. You can see they are green or white.
Let’s take a closer look at Florida for instance.
Unlike New York, Florida saw barely any cases before shut down. After reopening, it saw huge numbers of cases, peaking on July 12th. Why would Floridas numbers start to decrease if not for herd immunity? We know they aren’t being more careful. Disney land reopened and there is a police sheriff who literally made a rule that police officers and people going into the station were not allowed to wear masks.
Now let’s take a look at total percent infections in the US by state.
You can see that the States with the most total infections are the states that either haven’t had a second peak (NY, NJ) or have just gotten through a huge peak and are now on the down swing (LA, FL, AZ). I believe that this is because they either were or are now herd immune. If you have another explanation, I am all ears, but I really can’t think of one. I think when all states turn as red as Florida, we will as a country be herd immune.
So, say that I am correct about this, what does that mean? Well for one thing, we should be using this to guide reopening and school attendance. There are definitely some places that are safer than others. And for the love of god, let New York City folks out of jail a little bit. The Bronx is one of the safest places in the country right now. It is down right morbidly depressing in NYC because people are still so traumatized and worried. That isn’t to say that it is completely safe- it’s not- herd immunity just means that it is more safe- not totally safe.
For another thing, this means that this pandemic will be over soonish. If the whole country is herd immune, which could happen in a few months, then the pandemic is over for as long as antibodies last regardless of whether we have vaccine or not.
This gets me to my last piece of positive news with this. New York peaked on April 9th, four months ago. If they are herd immune, then immunity lasts at least four months. This is all pretty encouraging for vaccines and for not having this pandemic last forever. Cheers.
**** This analysis and the conclusions that I have drawn are my own and do not necessarily reflect the opinions of the wider scientific and medical communities. Please still be cautious with your health and the health of any at risk people you encounter. And for the love of god, wear a mask.