COVID-19 Vaccine Initiation and Dose Completion During the SARS-CoV-2 Delta Variant Surge in the United States, December 2020-October 2021.

OBJECTIVES: In summer 2021, the number of COVID-19-associated hospitalizations in the United States increased with the surge of the SARS-CoV-2 Delta variant. We assessed how COVID-19 vaccine initiation and dose completion changed during the Delta variant surge, based on jurisdictional vaccination coverage before the surge. METHODS: We analyzed COVID-19 vaccination data reported to the Centers for Disease Control and Prevention. We classified jurisdictions (50 states and the District of Columbia) into quartiles ranging from high to low first-dose vaccination coverage among people aged ≥12 years as of June 30, 2021. We calculated first-dose vaccination coverage as of June 30 and October 31, 2021, and stratified coverage by quartile, age (12-17, 18-64, ≥65 years), and sex. We assessed dose completion among those who initiated a 2-dose vaccine series. RESULTS: Of 51 jurisdictions, 15 reached at least 70% vaccination coverage before the Delta variant surge (ie, as of June 30, 2021), while 35 reached that goal as of October 31, 2021. Jurisdictions in the lowest quartile of vaccination coverage (44.9%-54.9%) had the greatest absolute (9.7%-17.9%) and relative (18.1%-39.8%) percentage increase in vaccination coverage during July 1-October 31, 2021. Of those who received the first dose during this period across all jurisdictions, nearly 1 in 5 missed the second dose. CONCLUSIONS: Although COVID-19 vaccination initiation increased during July 1-October 31, 2021, in jurisdictions in the lowest quartile of vaccination coverage, coverage remained below that of jurisdictions in the highest quartile of vaccination coverage before the Delta variant surge. Efforts are needed to improve access to and increase confidence in COVID-19 vaccines, especially in low-coverage areas.

Using a Cloud-Based Machine Learning Classification Tree Analysis to Understand the Demographic Characteristics Associated With COVID-19 Booster Vaccination Among Adults in the United States.

A tree model identified adults age ≤34 years, Johnson & Johnson primary series recipients, people from racial/ethnic minority groups, residents of nonlarge metro areas, and those living in socially vulnerable communities in the South as less likely to be boosted. These findings can guide clinical/public health outreach toward specific subpopulations.

Using a cloud-based machine-learning classification tree analysis to understand the demographic characteristics associated with COVID-19 booster vaccination among adults in the United States

A tree model identified adults aged ≤34 years, Johnson & Johnson primary series recipients, people from racial/ethnic minority groups, residents of non-large metro areas, and those living in socially vulnerable communities in the South as less likely to be boosted. These findings can guide clinical/public health outreach toward specific sub-populations.

Factors Associated with Delayed or Missed Second-Dose mRNA COVID-19 Vaccination among Persons >12 Years of Age, United States.

To identify demographic factors associated with delaying or not receiving a second dose of the 2-dose primary mRNA COVID-19 vaccine series, we matched 323 million single Pfizer-BioNTech (https://www.pfizer.com) and Moderna (https://www.modernatx.com) COVID-19 vaccine administration records from 2021 and determined whether second doses were delayed or missed. We used 2 sets of logistic regression models to examine associated factors. Overall, 87.3% of recipients received a timely second dose (≤42 days between first and second dose), 3.4% received a delayed second dose (>42 days between first and second dose), and 9.4% missed the second dose. Persons more likely to have delayed or missed the second dose belonged to several racial/ethnic minority groups, were 18-39 years of age, lived in more socially vulnerable areas, and lived in regions other than the northeastern United States. Logistic regression models identified specific subgroups for providing outreach and encouragement to receive subsequent doses on time.

Disparities in COVID-19 Vaccination Coverage Between Urban and Rural Counties - United States, December 14, 2020-January 31, 2022.

Higher COVID-19 incidence and mortality rates in rural than in urban areas are well documented (1). These disparities persisted during the B.1.617.2 (Delta) and B.1.1.529 (Omicron) variant surges during late 2021 and early 2022 (1,2). Rural populations tend to be older (aged ≥65 years) and uninsured and are more likely to have underlying medical conditions and live farther from facilities that provide tertiary medical care, placing them at higher risk for adverse COVID-19 outcomes (2). To better understand COVID-19 vaccination disparities between urban and rural populations, CDC analyzed county-level vaccine administration data among persons aged ≥5 years who received their first dose of either the BNT162b2 (Pfizer-BioNTech) or mRNA-1273 (Moderna) COVID-19 vaccine or a single dose of the Ad.26.COV2.S (Janssen [Johnson & Johnson]) COVID-19 vaccine during December 14, 2020-January 31, 2022, in 50 states and the District of Columbia (DC). COVID-19 vaccination coverage with ≥1 doses in rural areas (58.5%) was lower than that in urban counties (75.4%) overall, with similar patterns across age groups and sex. Coverage with ≥1 doses varied among states: 46 states had higher coverage in urban than in rural counties, one had higher coverage in rural than in urban counties. Three states and DC had no rural counties; thus, urban-rural differences could not be assessed. COVID-19 vaccine primary series completion was higher in urban than in rural counties. However, receipt of booster or additional doses among primary series recipients was similarly low between urban and rural counties. Compared with estimates from a previous study of vaccine coverage among adults aged ≥18 years during December 14, 2020-April 10, 2021, these urban-rural disparities among those now eligible for vaccination (aged ≥5 years) have increased more than twofold through January 2022, despite increased availability and access to COVID-19 vaccines. Addressing barriers to vaccination in rural areas is critical to achieving vaccine equity, reducing disparities, and decreasing COVID-19-related illness and death in the United States (2).

Disparities in First Dose COVID-19 Vaccination Coverage among Children 5-11 Years of Age, United States.

We analyzed first-dose coronavirus disease vaccination coverage among US children 5-11 years of age during November-December 2021. Pediatric vaccination coverage varied widely by jurisdiction, age group, and race/ethnicity, and lagged behind vaccination coverage for adolescents aged 12-15 years during the first 2 months of vaccine rollout.

Booster and Additional Primary Dose COVID-19 Vaccinations Among Adults Aged ≥65 Years - United States, August 13, 2021-November 19, 2021.

Vaccination against SARS-CoV-2 (the virus that causes COVID-19) is highly effective at preventing hospitalization due to SARS-CoV-2 infection and booster and additional primary dose COVID-19 vaccinations increase protection (1-3). During August-November 2021, a series of Emergency Use Authorizations and recommendations, including those for an additional primary dose for immunocompromised persons and a booster dose for persons aged ≥18 years, were approved because of reduced immunogenicity in immunocompromised persons, waning vaccine effectiveness over time, and the introduction of the highly transmissible B.1.617.2 (Delta) variant (4,5). Adults aged ≥65 years are at increased risk for COVID-19-associated hospitalization and death and were one of the populations first recommended a booster dose in the U.S. (5,6). Data on COVID-19 vaccinations reported to CDC from 50 states, the District of Columbia (DC), and eight territories and freely associated states were analyzed to ascertain coverage with booster or additional primary doses among adults aged ≥65 years. During August 13-November 19, 2021, 18.7 million persons aged ≥65 years received a booster or additional primary dose of COVID-19 vaccine, constituting 44.1% of 42.5 million eligible* persons in this age group who previously completed a primary vaccination series.† Coverage was similar by sex and age group, but varied by primary series vaccine product and race and ethnicity, ranging from 30.3% among non-Hispanic American Indian or Alaska Native persons to 50.5% among non-Hispanic multiple/other race persons. Strategic efforts are needed to encourage eligible persons aged ≥18 years, especially those aged ≥65 years and those who are immunocompromised, to receive a booster and/or additional primary dose to ensure maximal protection against COVID-19.

SARS-CoV-2, Mannerism, Marten, Mink, and Man

Among the many mustelids are wolverines, weasels (including ermines), otter, badgers, marten (including sables), ferrets, and mink. Since the early Middle Ages, the quest for furs of these animals has played a role in European national expansion into areas where fur-bearing mustelids were populous, including Russia’s expansion into Siberia and France and England’s expansion into North America. Recent experimental research has shown that many mammals can be infected with the virus, including cats, dogs, bank voles, deer mice, fruit bats, ferrets, hamsters, mink, skunks, pigs, rabbits, raccoon dogs, tree shrews, white-tailed deer, rhesus macaques, and cynomolgus macaques. In January 2021, a combined report of the Food and Agriculture Organization of the United Nations, the World Organisation for Animal Health (OIE), and the World Health Organization presented data from OIE and other sources from 36 countries with mink farming industries and documented widespread virus transmission, in both Europe and North America. Because of concerns that mink farm populations could serve as a reservoir for ongoing coronaviruses transmission and result in development of mutations that would undermine the effectiveness of SARS-CoV-2 vaccines, large-scale culling of these animals has been pursued by Denmark, the Netherlands, and Spain. [...]it appears that in addition to all the human-to-human contact prevention measures needed to control and eliminate SARS-CoV-2 transmission, interventions that reduce contact of humans or domestic (or farmed) animals with bats or other susceptible wild animals will be needed to avert future spillover with pandemic potential.