The United States is a few days from reaching President Biden’s goal of vaccinating 100 million people 100 days after taking office. While the United States leads the world in both the number of COVID-19 cases at over 29.7 million and deaths reaching over 539,000, it has taken a step as a leader in vaccinating his people.
However, the standard vaccination strategy does not take into account the baseline breeding number (R.0), which helps to estimate the prevalence of COVID-19 cases.
New pre-printed research paper published on the medRxiv* a server with Anthony R. Ives of the University of Wisconsin-Madison and Claudio Bozzuto of the Wildlife Study GmbH recommends that routine United States vaccination efforts achieve herd immunity in about 4.5 months. However, they argue a more cost-effective and geographically effective vaccination strategy. This would help distribute vaccines for counties with high and likely low population populations. These counties are currently on track to become the last to reach herd immunity under the conventional immunization circulation strategy.
The authors write:
“From an epidemiological perspective, because there are differences in R.0 values among counties are driven in part by their population density, counties with the greatest risk of recovery and eventual major catastrophes reach herd immunity. From a socio-economic perspective, these high-density counties comprise many of the U.S. economic engines. Finally, African American populations are quite large in high-density counties, and the current circulation plan continues to lag about 4 days behind whites in reaching immunity. treud. “
The proposed vaccination strategy targets counties with a high R level.0 numbers
Because urban environments are at high risk for the spread of the virus, dense populations produce a higher estimate of R.0. Therefore, the authors argue that vaccination strategies should focus on dense populations to reach herd immunity more quickly and avoid more COVID-19 cases.
To work this out, they would monitor the proportion of U.S. populations that would reach herd immunity under the conventional dispersal strategy. Starting from March 15, 2021, they assume the following: the standard vaccine level would use one of three FDA-approved vaccines – Moderna, Pfizer-BioNTech, or Johnson & Johnson – 1.58 million daily dose when 71.1 million people have already been vaccinated. with at least one dose, vaccines are 90% effective, and people who are vaccinated against COVID-19 cannot.
Their results showed that herd protection in the United States could be reached in about 130 days.
Possible and effective administration of SARS-Cov-2 vaccines according to R0. Panel (a) shows the proportion of the U.S. population living in counties that have reached herd immunity, measured as 1 – 1 / R0 at the county level; day 0 on the x-axis is 15 March 2021. The black line assumes the current distribution in which vaccines are distributed evenly to counties according to population size, and the red line assumes that the distribution is dependent on the approximate county level values R0. Panel (b) shows the average population density of the counties (individuals per km2) that reach herd immunity in a weekly time window. Panel (c) lists the proportion of white and African American communities living in counties that have achieved herd protection.
New plan achieves faster herd protection in all counties
In contrast, their analysis suggests that their proposed strategy would help the United States herd protection around the same for all counties and 51 days faster than the current immunization strategy. In addition, the United States would eventually use 39% fewer vaccines under the new plan.
“These results are up to the R.0mid-March based strategy; overall benefits are expected to wane as the population – based strategy lasts. “
With new changes of concern from the United Kingdom, South Africa and Brazil, the researchers note that these estimates may change, and more vaccines may be needed.
To account for the higher transmission rates of the new variables, they modified their mathematical formula to include a transmission 1.5 times higher than that initially estimated at the onset of the entire disease. -distributed in 2020.
The results show that, with the researchers’ proposed strategy, the United States would reduce the time to reach herd protection by 76 days and use up less than 35% of their vaccine doses.
The evidence confirms that greater vaccination efforts in more populated counties would be fairer and more effective, use fewer vaccines in the long term, and achieve faster herd immunity.
* Important message
medRxiv publish preliminary scientific reports that are not peer-reviewed and, therefore, should not be seen as final, guiding health-related clinical practice / behavior, or be treated as information established.