COVID-19 Blog

UVA COVID-19 Modeling Weekly Update

Key Takeaways

  • Cases and testing are slightly down after the holiday break, similar to the downtick seen last year following holidays. We expect a rebound later this week.
  • Across the Commonwealth, activity remains mixed, with 18 of the 35 health districts in slow growth, and another 10 in decline.
  • Current model projections suggest a flattening case trajectory in the near-term, with gradual growth starting in the new year.
  • Seasonal factors and holiday travel may shift trajectories towards more rapid growth as seen in the “FallWinter” modeling scenario.
  • The models have been updated to more accurately account for differing immunity profiles. This will be key to modeling the new Omicron variant, which has not yet been detected in Virginia.

Weekly Modeling Report.

UVA COVID-19 Model Dashboard.

UVA Biocomplexity Institute Slides.

VDH COVID-19 Surveillance Data Update.

UVA COVID-19 Modeling Weekly Update

Key Takeaways

  • Case rates in Virginia have leveled off. No health districts are in Surge, but several are now showing Slow Growth. Overall, Virginia’s trajectory has moved from Declining to Plateau.
  • Self-reported mask usage has stalled across Virginia, with 61.5% of respondents masking when in crowded public places (down from 65.5% in the first week of November).
  • Booster vaccine administrations have tapered slightly, but the authorization of Pfizer vaccine for children aged 5-11 years has caused an significant increase in first time dose administrations.
  • Models continue to forecast a slow decline, but also suggest that seasonal factors and holiday travel could shift our trajectory towards another winter surge rivaling that of Winter 2020.

Note: There will be no weekly update next week due to the Thanksgiving holiday.

Weekly Modeling Report.

UVA COVID-19 Model Dashboard.

UVA Biocomplexity Institute Slides.

VDH COVID-19 Surveillance Data Update.

Tracking COVID-19 Disparities

The Virginia Department of Health tracks COVID-19 disparities by race and ethnicity for cases, hospitalizations, deaths, and vaccinations. This is important because underlying health and social inequities put some racial and ethnic groups at greater risk than others. By examining disparities over the course of the pandemic, it is possible to get a sense of where they have improved and where improvement is still needed.

Early in the pandemic it became clear disparities were severe across the United States, so the Virginia Department of Health began tracking cases, deaths, and hospitalizations by race, ethnicity, age, and socioeconomic status, to learn how different groups were impacted. Mortality was disproportionately higher for racial and ethnic minority persons than for White persons.This analysis compares three different periods of the pandemic in Virginia to better understand disparities within the Commonwealth and how they have changed so far.

Health Disparity Rate Ratios

Rate ratios are used to quantify disparity. A rate ratio compares the rate of events in different groups to a reference group and expresses it as a simple ratio. A previous blog post, Health Disparity Rate Ratios, goes into greater detail about them. In general, higher rate ratios mean higher rates within one group compared to the reference group. 

March 2020 – September 2020

During the spring and summer of 2020, cases surged across the United States and disparities were more pronounced than at any other point in the pandemic. The 7-day moving average of cases in Virginia hovered around 1,000 during this time. Latino people were most impacted initially; they were more likely to get COVID-19, and subsequently die from it, compared to any other group in Virginia, with case rates consistently at least five times the rate of White people. Black people also had case and death rates that were twice as high as White people. 

Some of the early disparities in cases likely stemmed from outbreaks among front-line and essential workers, particularly those in the meat and poultry industry. Lessons learned from these early outbreaks helped to inform future responses and outreach. For example, one investigation into outbreaks in Chesterfield County and Richmond City identified lack of accessible health information in Spanish, lack of insurance and paid sick leave, and employment in frontline industries as risk factors for COVID-19 in Latino communities. Public health officials and policy-makers responded with strategies to address these disparities.

 

October 2020 – February 2021

In the fall of 2020 and winter of 2020-2021, the number of cases in Virginia reached new highs while racial and ethnic disparities began to decline. The 7-day moving average of cases rose from around 1,000 in October to over 5,000, and remained above 3,000 through February. This was the highest peak in cases during the pandemic so far.

During the peak, Latino people still had a case rate of about four times that of White people, but by January 2021, that number dropped to 2.2.

A similar trend can be seen for Black people, decreasing from 1.9 times that of White people to around 1.4 times. Asian or Pacific Islander people remained near or below the cumulative case rate of White people throughout the pandemic. 

 

March 2021 – August 2021

Disparity in COVID-19 case and death rates changed significantly after March 2021, when 21% of people in Virginia had received at least one dose of vaccine and cases briefly dipped to lower  levels. In June, the 7-day moving average was as low as 145, though it quickly returned to over 3,000. Now, with varying levels of vaccine uptake among racial and ethnic groups, COVID-19 disparities have shifted.

The current COVID-19 vaccines have been proven to be effective at preventing infection, severe illness, and death from COVID-19; they are the most important preventive measure to reduce the impact of the virus on individuals and communities. The extent to which racial and ethnic minorities are vaccinated has likely affected case and death rate disparities in Virginia.

 

 

Asian and Pacific Islander people have a higher overall vaccination rate, around 1.3 times that of White people. Additionally, Latino people are now the second most vaccinated group, while White and Black people are less likely to be vaccinated. 

Monthly rate ratios are better at indicating the direction of disparities, or current trend, than cumulative rate ratios. The following graph of monthly death rate ratios depicts a new trend from March 2021 onward, where case and death rate ratios for Latino people have better parity. Latino people had the highest death rates early in the pandemic.

 

 

Vaccine hesitancy is a significant barrier to decreasing death rates for all groups in Virginia, and is a particular issue among Black communities. Further research is needed to fully understand the impact, but the extent to which different racial and ethnic groups in Virginia are getting vaccinated is likely affecting death rates from COVID-19. Trends in COVID-19 case and death rate disparities are likely to change as more people get vaccinated. The Virginia Department of Health updates rate ratios monthly on its COVID-19 Cases & Testing Dashboards to maintain its commitment to transparently tracking COVID-19 disparities in the Commonwealth. 

 

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* The impact of the Delta variant cannot be fully presented due to the lack of data points since July when it became the major variant.

*American Indian and Alaska Natives were not included in this analysis due to the small size of that population.

References

  1. Webb Hooper M, Nápoles AM, Pérez-Stable EJ. COVID-19 and Racial/Ethnic Disparities. JAMA. 2020;323(24):2466–2467. doi:10.1001/jama.2020.8598

UVA COVID-19 Modeling Weekly Update

Key Takeaways

  • The cadence of COVID-19 modeling projections has been reduced to bi-weekly. This is an abbreviated interim report.
  • Statewide community transmission rates remains “High” with over 100 weekly cases per 100,000 residents.
  • Case rates continue to decline, but this trend appears to be slowing. Four health districts are now experiencing slow growth, six others have recently plateaued, and the statewide Re is slowly climbing.
  • Models continue to forecast a decline in cases. But they also suggest the possibility of another surge if winter weather and travel increase transmission rates to match those of Winter 2020.
  • Stay safe during the holidays by following CDC guidance.

Weekly Modeling Report.

UVA COVID-19 Model Dashboard.

UVA COVID-19 Modeling Weekly Update

Key Takeaways

  • Cases continue to decline or plateau across the Commonwealth. Nevertheless, case rates remain high in some regions, particularly Southwest Virginia.
  • So far, Virginia has not seen a repeat of increased transmission rates seen last fall. This reduces the expected impact of a potential holiday surge. Nevertheless, the model shows a large surge is possible under current vaccination rates.
  • First dose vaccinations have ticked up recently, and booster shot uptake has been robust.
  • Metaculus forecasters place a 30% chance on the possibility of cases exceeding the Delta surge during the 1st quarter of 2022.

Weekly Modeling Report.

UVA COVID-19 Model Dashboard.

UVA Biocomplexity Institute Slides.

VDH COVID-19 Surveillance Data Update.