1/ Why we can’t wait 'til Halloween for COVID to disappear

Vaccine distribution is the #1 worldwide public health issue. Here’s why: we need to stop the daily death toll. Bottom line: vaccination rates need to be doubled, tripled or quadrupled, and RIGHT NOW!

2/ A useful analogy is the 2009 H1N1 flu vaccine rollout. It was a quickly developed, effective vaccine. Yet a slow rollout meant the vaccine did not substantially impact the H1N1 pandemic. This cannot be repeated with COVID. The stakes (and mortality) are considerably higher.

3/ Below I illustrate why we need to ramp up COVID vaccination, by how much, and how fast we can get to “herd immunity”. As a caveat, this is only an estimate.

4/ Slightly > 9 million Americans have been vaccinated for COVID, about 300k people per day in the last month.
COVID vaccination has two purposes: 1) protect vaccinated individuals, 2) prevent community transmission and produce herd immunity. https://covid.cdc.gov/covid-data-tracker/#vaccinations

5/ Herd immunity is indirect protection that emerges when enough people have immunity, which comes from either vaccination or infection + survival. Yet, vaccination only helps non-immune people: people who have not been infected before or infected but have no antibodies.

6/ Of the 300k per day, it is unknown what percentage have had COVID. But it’s probably > 10-20% given healthcare providers and nursing home residents are prioritized and at high risk for having had COVID. So, assume that 7 million non-immune people have been vaccinated.

7/ As immunity increases, there are fewer opportunities for infection. When herd immunity is reached, additional infections among the non-immune drastically decline. Herd immunity = 1-(1/Ro). Ro is the average number of people infected by one infectious individual.

8/ Ro for COVID is elusive but lies between 2 and 4. For the new, more transmissible COVID variant, Ro is probably higher. Therefore, the herd immunity threshold for COVID is from 50-80%, assuming Ro for the new variant is 5. (Note: this is unknown)

9/ Worst case, that means that 80 in 100 need to be immune for the “herd” to be immune. (Note: Herd immunity is also regional but bear with me through this thought experiment).

10/ About 22m have had COVID + survived. The actual infection rate is ~ 5 to 10x, because only a % with COVID get tested. For simplicity, ~ 110 million Americans have had COVID and survived (Note: ballpark estimate).

11/ There are 330m Americans. To reach herd immunity, 80% or 264 million need immunity. Subtracting the 110 million who have had it and the 7 million non-immune and vaccinated, that leaves about 150 million to either get COVID + survive or get the vaccine to reach herd immunity.

12/ There are currently ~ 200k documented COVID infections daily and ~ 1 million real daily infections. This may peak in the next few weeks then fall. Over the next 3 months, I estimate a 500,000 daily infections, or ~ 50 m people will get COVID & recover. ~ 200k more will die.

13/ Therefore, in the next three months, we need to vaccinate 100 million Americans to reach herd immunity by mid-April. In my modeling, I assume infections will go down in the summer and spike up again in the winter 2021.

14/ So here are my estimates. These #s also assume that people getting the vaccine are not in the 110m who already had COVID and survived.

15/

Starting today, if we vaccinate 1.1 million non-immune people per day, herd immunity will come mid-April 2021.

At 500k per day, herd immunity is mid-June 2021.

At 300k per day (like last month), herd immunity is…wait for it…end of October 2021. Yep. Halloween 2021.

16/ Getting to herd immunity more slowly means more preventable infections and more preventable deaths, repeating the 2009 H1N1 performance but with worse results. The case fatality rate for H1N1 was 0.02%. The case fatality rate for COVID (with documented infection) is 1-2%

17/ It also means waiting longer to get the final word we can safely take off our masks, eat in restaurants, go to bars & sporting events. Slow vaccination is a multi-level problem: manufacturing, underfunding of health depts, lack of central leadership & fragmentation of care.

18/ The most important "race" in America today: the speed of COVID infections and the speed of vaccination. COVID is currently the "hare" and vaccination efforts are the "tortoise". It's time to ramp up vaccination!