Excess COVID-19 associated deaths among the unvaccinated population >= 18 years old in the US, May 30 through December 4, 2021

Vaccines against SARS-CoV-2 were authorized at the end of 2020 and are effective in preventing deaths; however, many persons remain unvaccinated. Using weekly publicly available CDC data of COVID-19-associated death rates by age and vaccination status from 26 US jurisdictions, we estimated the number of excess deaths that might have been averted by vaccination among unvaccinated persons [≥] 18 years old from May 30 to December 4, 2021. We subtracted the death rate in the vaccinated from rates in the unvaccinated to estimate the death rate each week that could be attributable to non-vaccination and multiplied this rate difference by the number of people in the unvaccinated group for each age group and each week, to estimate the excess mortality among the unvaccinated. Then, we extrapolated the number of deaths due to non-vaccination in the 26 jurisdictions to the whole US population using 2020 census estimates. In the 26 participating jurisdictions there were an estimated 83,400 excess deaths among the unvaccinated from May 30 to December 4, 2021. The largest number of excess deaths occurred in those 65-79 years old (n=28,900; 34.7% of total), followed by those 50-64 years old (n=25,900; 31.1%). Extrapolated to the US population we estimated approximately 135,000 excess deaths during the study period in persons [≥]18 years old. Our estimates are an underestimate of all excess deaths that have occurred since vaccine became available because our analysis period was limited to May 30 to December 4, 2021, and many excess deaths occurred before and after this period. In summary, we used retrospective data to estimate the substantial number of COVID-19-associated deaths among the unvaccinated illustrating the importance of vaccination to prevent further unnecessary mortality during this pandemic.

Estimates of presumed population immunity to SARS-CoV-2 by state in the United States, August 2021

BackgroundInformation is needed to monitor progress toward a level of population immunity to SARS-CoV-2 sufficient to disrupt viral transmission. We estimated the percentage of the United States (US) population with presumed immunity to SARS-CoV-2 due to vaccination, natural infection, or both as of August 26, 2021. MethodsPublicly available data as of August 26, 2021, from the Centers for Disease Control and Prevention (CDC) were used to calculate presumed population immunity by state. Seroprevalence data were used to estimate the percentage of the population previously infected with SARS-CoV-2, with adjustments for underreporting. Vaccination coverage data for both fully and partially vaccinated persons were used to calculate presumed immunity from vaccination. Finally, we estimated the percentage of the total population in each state with presumed immunity to SARS-CoV-2, with a sensitivity analysis to account for waning immunity, and compared these estimates to a range of population immunity thresholds. ResultsPresumed population immunity varied among states (43.1% to 70.6%), with 19 states with 60% or less of their population having been infected or vaccinated. Four states have presumed immunity greater than thresholds estimated to be sufficient to disrupt transmission of less infectious variants (67%), and none were greater than the threshold estimated for more infectious variants (78% or higher). ConclusionsThe US remains a distance below the threshold sufficient to disrupt viral transmission, with some states remarkably low. As more infectious variants emerge, it is critical that vaccination efforts intensify across all states and ages for which the vaccines are approved. SummaryAs of August 26, 2021, no state has reached a population level of immunity thought to be sufficient to disrupt transmission. (78% or higher), with some states having remarkably low presumed immunity.

Continued need for non-pharmaceutical interventions after COVID-19 vaccination in long-term-care facilities

Long-term care facilities (LTCFs) bear disproportionate burden of COVID-19 and are prioritized for vaccine deployment. LTCF outbreaks could continue occurring during vaccine rollout due to incomplete population coverage, and the effect of vaccines on viral transmission are currently unknown. Declining adherence to non-pharmaceutical interventions (NPIs) against within-facility transmission could therefore limit the effectiveness of vaccination. We built a stochastic model to simulate outbreaks in LTCF populations with differing vaccination coverage and NPI adherence to evaluate their interacting effects. Vaccination combined with strong NPI adherence produced the least morbidity and mortality. Healthcare worker vaccination improved outcomes in unvaccinated LTCF residents but was less impactful with declining NPI adherence. To prevent further illness and deaths, there is a continued need for NPIs in LTCFs during vaccine rollout.

The importance of continued non-pharmaceutical interventions during the upcoming SARS-COV-2 vaccination campaign

In this communication we assess the potential benefit of SARS-COV-2 pandemic vaccination in the US and show how continued use of non-pharmaceutical interventions (NPIs) will be crucial during implementation.