FINAL UPDATE: March 09, 2021
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When I launched this project late December 2020, major outlets were not tracking daily vaccination progress nor the path to herd immunity. Now, major publications have well-developed dashboards.

Thanks to the small but loyal following. I leave this project very optimistic about the progress of the vaccination campaign, and encourage everyone to be vaccinated when it’s your turn in line!

# U.S. Covid-19 Vaccine Campaign Progress

### Daily First Doses Given in U.S.

The U.S. Covid-19 vaccination campaign began in earnest in December, 2020 after the dual emergency use authorizations of the Pfizer-BioNTech and Moderna mRNA vaccine candidates. The vaccines contain “a small piece of the Covid-19 virus’s mRNA that instructs cells in the body to make the virus’s distinctive ‘spike’ protein. After a person receives this vaccine, their body produces copies of the spike protein, which does not cause disease, but triggers the immune system to learn to react defensively, producing an immune response against SARS-CoV-2.”

# Covid-19 Vaccine Distribution

### State Allocation vs. Distribution

Though the vaccines were developed and approved in record time, the vaccine distribution campaign began on a slow and concerning start. Though the federal government’s Operation Warp Speed fell far short of its initial goal to deliver 20 million vaccinations by the end of December, improvements in distribution make it quite clear the U.S. will hit the Biden administration’s goal of 100 million vaccine doses in his first 100 days. The U.S. is now hovering around Biden’s next goal of ~1.5 million doses per day, and with increased supply down the pipeline, is hoping to reach 2+ million doses a day.

But forget goals - what if the U.S. distributed all the vaccine supply promised to it by Moderna and Pfizer (220 million doses by end of Q1 2021), plus the single shots from Johnson & Johnson? We could hit herd immunity be early June.

# When Will the U.S. Achieve Herd Immunity?

The majority of public health experts have estimated general herd immunity is achieved somewhere around 70% protection, though some experts have recently estimated that higher protection rates are necessary.

The percent to herd immunity calculations presented in the figure above assume this 70% protection rate and some form of protection against reinfection from Covid-19 antibodies. While the true herd immunity protection threshold may be higher than 70%, the true number of U.S. Covid-19 cases may also be substantially underestimated.

$$\text{herd immunity date} = D$$

$\text{ where:}$

$\sum_{n=a}^{i} C_n + \sum_{n=b}^{i} \frac{V_n}{2}+ \sum_{n=i}^{D} (\frac{\hat V_n}{2} + \hat C_n) = .70*USpop$ $\text{and:}$

$$a = \text{date of first Covid-19 case}$$

$$i = \text{today's date}$$

$$C = \text{daily Covid-19 cases confirmed}$$

$$b = \text{date of first vaccine dose given}$$

$$V = \text{daily vax doses given}$$

$$\bar v = \text{seven day rolling average of daily vax doses given}$$

$$\hat V = \text{projected daily vax doses given} = \bar v$$

$$\bar c = \text{seven day rolling average of daily Covid cases confirmed}$$

$$\hat C = \text{projected daily Covid-19 cases} = \bar c$$

$$USpop = 330,000,000$$

Such uncertainty could lead to herd immunity being achieved either more quickly or more slowly than projected above. Thus, these figures are meant to illustrate a rough approximation of the country’s progress towards herd immunity, rather than a definitive projection.

At the rolling seven-day average vaccination and case rates, the U.S. is projected to achieve herd immunity July 21, 2021. All assumptions considered, this is likely a conservative date - assuming single-dose vaccines are introduced into distribution from Johnson & Johnson and/or AstraZeneca, and the rate of daily vaccinations continues to increase.

What is more certain is that to achieve herd immunity by Covid-19 infection alone, as some fringe public health commentators and right-wing politicians have previously suggested the U.S. do, approximately 11,214,043 more Americans would die!