Anchorage’s acting mayor has extended her emergency COVID order until residents of the municipality have reached the minimum of 70% vaccinated. The inference is that “herd immunity” will be reached only through vaccinations. This is not correct and does not meet the public health concept and metrics of “herd immunity.”
Health officials around the world are racing to vaccinate enough people to stop the spread of COVID-19. The goal is to reach “herd immunity,” which is when enough people have immunity, either from vaccination and/or a past COVID-19 infection that produces natural immunity to the COVID-19 virus. This, in turn, stops the uncontrolled spread of the virus.
Herd immunity doesn’t make any one person immune, and outbreaks can still flare up. Rather, it means a virus is no longer easily jumping from person to person, which helps protect those who are still vulnerable from catching it.
Many experts including Dr. Walter Orenstein, infectious disease expert at Emory University, say this virus’ herd immunity threshold should begin at around 60% and start reducing virus spread, hospitalizations and deaths at 70%, but don’t wait for any big declaration that we’ve reached that milestone. It is the reduction in deaths and use of inpatient healthcare systems that will confirm it, and this may vary by city or region.
Municipality of Anchorage and State of Alaska cases of COVID-19 virus transmission continue to decline since its peak in December 2020. The small increase in the last seven days is primarily in the 20-39 age group, not in the 60-plus group that produces the majority COVID-19 hospitalizations, ICU occupancy, ventilator usage and deaths now reported by the Alaska Department of Health data hub.
As of April 12, 2021, 37.5% of Anchorage’s population (not including American Indian/Alaska Native vaccines, which come from a different provider – Indian Health Service) has received at least one dose of the vaccine. Another 39.9% population has been infected and now has immunity to the virus. This is based on the FundStrat’s method of calculation for herd immunity (confirmed COVID-19 cases and total infections per 1mm residents). Therefore more than 77% of Anchorage’s population now has immunity. That meets the percentage needed to end the acting mayor’s emergency order.
Proof that we’re near or beyond herd immunity threshold is the disruption in the chain of transmission. This is how to determine whether to relax restrictions – watching infection and hospitalization tends as vaccinations are rolled out. COVID-19 cases, deaths and hospitalization have all dropped since Jan 8, 2021.
COVID-19 Impatient Beds, ICU Beds Occupied and Ventilators in use by Patients As of Apr. 12, 2021:
- Inpatient Bed Occupied by COVID-19 Patients: 4.2% of Total Impatient Beds
- ICU Bed Occupied by COVID-19 Patients : 16.2% of Total ICU Beds
- Ventilators in use for COVID-19 Patients: 3.9% of Ventilators used
The data box above (Herd Immunity Update Report State of Alaska As of Mar 31, 2021) details that 73% of Alaska’s statewide population has been infected with the virus and has immunity or received the COVID-19 vaccine.
This article is co-authored by the following writers:
- Healthcare Economist (Team Leader)
- Fellow, Healthcare Financial Managers Association (HFMA)
- American Society of Health Economists (ASHE.com)
Ric Davidge, MPA
- Founder/Chairman of Alaska Roundtable