September 13, 2021 – By most accounts, the Delta variant rocked the United States, much as it has worldwide. Many observers question why vaccines had not done a better job in minimizing the devastation. However, a deeper consideration of the evidence suggests the vaccines altered the length, intensity, and age-based experience with the virus.
Let’s start with the encouraging news: The Delta wave has crested in the United States and begun to wane.
Using reported cases, the crest occurred on September 2. In the intervening week, new daily cases dropped 12%. Using estimated infections, this wave peaked on August 21 or 22. We should note the natural delay embedded in reported cases – the incubation period from infection to testing to reporting – explains much or all this difference in the crest’s timing.
We can glean fascinating insight by comparing the Delta peak to the previous peak, experienced in early January. Overall, reported cases during the Delta-peak reached 88% of the January peak. Estimated infections extended to 80% of the January peak. Covid hospital census topped out at a similar 80% of the January peak. Importantly, deaths only reached 41% of the January peak.
It sounds like the Delta-peak nearly matched the January peak, despite the vaccination effort.
Let’s dig deeper.
The differences are starker when we compare the length and intensity of the two surges. From its origin to crest, the Fall/Winter wave lasted 107 days. The Delta wave was more than a month shorter, at 73 days. On average, 76% more people reported a new infection in the earlier wave; 53% more infected people were admitted to hospitals daily. More than 2.5 times as many people died each day with Covid.
In the Fall/Winter surge, one person died for every 86 new cases and one for every 5.6 hospital admissions. During the Delta surge, these rates dropped to one death per 129 new cases and one death for every ten hospital admissions.
Lastly, we should note the profound differences in how these two surges impacted people of different age groups. Senior citizens were 2.5-to-3 times more likely to be infected at the peak of the Fall/Winter surge than at the peak of the Delta surge. Persons 18-to-49 years old were twice as likely to be infected at the height of the earlier wave.
Contrast this with children 0-to-15 years old: Without the benefit of vaccines, these kids were equally likely to be infected at the peak of the two surges.
The risk of infection is now higher among minors than among senior citizens.
Hospital rates followed a similar pattern: seniors were 2.7 times more likely to be admitted to a hospital at the peak of the Fall/Winter surge than the Delta peak. However, minors were more likely to be admitted during the Delta-peak than the earlier one. Hospitalization rates are still markedly lower for minors than senior citizens (11-to-19 times lower) and non-senior adults (4-to-6 times lower).
Fortunately, minors continue to enjoy near-total defense against death (with, of course, tragic exceptions). The death risk to senior citizens was ten times lower at the peak of the Delta surge than during the Fall/Winter peak.
This analysis leads to two significant conclusions and an unmet need: the Delta variant is a formidable and fast-spreading form of the virus. At the same time, vaccines served to both shorten and limit the intensity of the surge. Tens of thousands of lives were likely spared.
The unmet need? Vaccinating schoolchildren.
While we are fortunate that children have a substantially lower risk of being hospitalized or dying from an infection, it is unconscionable to deny them vaccine access when their risk of infection is higher than for senior citizens.
Contributing writer:
Mark A. Van Sumeren, strategic advisor, Medical Devices & Integrated Delivery Networks
Health Industry Advisor LLC, provides a regular report on COVID-19 numbers for the health care industry.
For more information, or to sign up for the report, contact Mark at Mark.VanSumeren@HealthIndustryAdvisor.com; or visit www.HealthIndustryAdvisor.com.