SARS-CoV-2 Infections and Hospitalizations Among Persons Aged ≥16 Years, by Vaccination Status - Los Angeles County, California, May 1-July 25, 2021.

COVID-19 vaccines fully approved or currently authorized for use through Emergency Use Authorization from the Food and Drug Administration are critical tools for controlling the COVID-19 pandemic; however, even with highly effective vaccines, a proportion of fully vaccinated persons will become infected with SARS-CoV-2, the virus that causes COVID-19 (1). To characterize postvaccination infections, the Los Angeles County Department of Public Health (LACDPH) used COVID-19 surveillance and California Immunization Registry 2 (CAIR2) data to describe age-adjusted infection and hospitalization rates during May 1-July 25, 2021, by vaccination status. Whole genome sequencing (WGS)-based SARS-CoV-2 lineages and cycle threshold (Ct) values from qualitative reverse transcription-polymerase chain reaction (RT-PCR) for two SARS-CoV-2 gene targets, including the nucleocapsid (N) protein gene region and the open reading frame 1 ab (ORF1ab) polyprotein gene region,* were reported for a convenience sample of specimens. Among 43,127 reported SARS-CoV-2 infections in Los Angeles County residents aged ≥16 years, 10,895 (25.3%) were in fully vaccinated persons, 1,431 (3.3%) were in partially vaccinated persons, and 30,801 (71.4%) were in unvaccinated persons. Much lower percentages of fully vaccinated persons infected with SARS-CoV-2 were hospitalized (3.2%), were admitted to an intensive care unit (0.5%), and required mechanical ventilation (0.2%) compared with partially vaccinated persons (6.2%, 1.0%, and 0.3%, respectively) and unvaccinated persons (7.6%, 1.5%, and 0.5%, respectively) (p<0.001 for all comparisons). On July 25, the SARS-CoV-2 infection rate among unvaccinated persons was 4.9 times and the hospitalization rate was 29.2 times the rates among fully vaccinated persons. During May 1-July 25, the percentages of B.1.617.2 (Delta) variant infections estimated from 6,752 samples with lineage data increased among fully vaccinated persons (from 8.6% to 91.2%), partially vaccinated persons (from 0% to 88.1%), and unvaccinated persons (from 8.2% to 87.1%). In May, there were differences in median Ct values by vaccination status; however, by July, no differences were detected among specimens from fully vaccinated, partially vaccinated, and unvaccinated persons by gene targets. These infection and hospitalization rate data indicate that authorized vaccines were protective against SARS-CoV-2 infection and severe COVID-19 during a period when transmission of the Delta variant was increasing. Efforts to increase COVID-19 vaccination, in coordination with other prevention strategies, are critical to preventing COVID-19-related hospitalizations and deaths.

Excess Mortality Associated With the COVID-19 Pandemic-Los Angeles County, March-September 2020.

OBJECTIVE: To more comprehensively estimate COVID-19-related mortality in Los Angeles County by determining excess all-cause mortality and pneumonia, influenza, or COVID (PIC) mortality. DESIGN: We reviewed vital statistics data to identify deaths registered in Los Angeles County between March 15, 2020, and August 15, 2020. Deaths with an ICD-10 (International Classification of Diseases, Tenth Revision) code for pneumonia, influenza, or COVID-19 listed as an immediate or underlying cause of death were classified as PIC deaths. Expected deaths were calculated using negative binomial regression. Excess mortality was determined by subtracting the expected from the observed number of weekly deaths. The Department of Public Health conducts surveillance for COVID-19-associated deaths: persons who died of nontraumatic/nonaccidental causes within 60 days of a positive COVID-19 test result were classified as confirmed COVID-19 deaths. Deaths without a reported positive SARS-Cov-2 polymerase chain reaction result were classified as probable COVID-19 deaths if COVID-19 was listed on their death certificate or the death occurred 60 to 90 days of a positive test. We compared excess PIC deaths with the number of confirmed and probable COVID-19 deaths ascertained by surveillance. SETTING: Los Angeles County. PARTICIPANTS: Residents of Los Angeles County who died. MAIN OUTCOME MEASURE: Excess mortality. RESULTS: There were 7208 excess all-cause and 5128 excess PIC deaths during the study period. The Department of Public Health also reported 5160 confirmed and 323 probable COVID-19-associated deaths. CONCLUSIONS: The number of excess PIC deaths estimated by our model was approximately equal to the number of confirmed and probable COVID-19 deaths identified by surveillance. This suggests our surveillance definition for confirmed and probable COVID-19 deaths might be sufficiently sensitive for capturing the true burden of deaths caused directly or indirectly by COVID-19.

Meningococcal Disease Surveillance in Men Who Have Sex with Men - United States, 2015-2016.

Meningococcal disease is a rare, but serious, bacterial infection that progresses rapidly and can be life-threatening, even with prompt antibiotic treatment. Men who have sex with men (MSM) have previously been reported to be at increased risk for meningococcal disease compared with other men, and recent outbreaks of serogroup C meningococcal disease among MSM have occurred (1). However, the epidemiology of meningococcal disease among MSM in the United States is not well described, in part, because information about MSM has not historically been collected as part of routine meningococcal disease surveillance. To better characterize and identify risk factors for meningococcal disease in general, supplementary data and isolates have been collected since 2015 through enhanced meningococcal disease surveillance activities. During 2015-2016, 271 cases of meningococcal disease in men aged ≥18 years were reported to the National Notifiable Diseases Surveillance System (NNDSS) in 45 states participating in this enhanced surveillance. Forty-eight (17.7%) cases were in men identified as MSM, including 17 (37.8%) with human immunodeficiency virus (HIV) infection. Among MSM, 39 (84.8%) cases were caused by Neisseria meningitidis serogroup C, whereas this serogroup was responsible for only 16.4% of cases among men who were not known to be MSM (non-MSM). Despite improvements in surveillance, MSM likely remain underascertained among men with meningococcal disease. Improved surveillance data are needed to understand the prevalence of and risk for meningococcal disease among MSM and inform policy and prevention strategies. Vaccination with quadrivalent meningococcal conjugate (MenACWY) vaccine is recommended for the control of meningococcal disease outbreaks caused by serogroups A, C, W, or Y, including during outbreaks among MSM; in addition, all persons aged ≥2 months with HIV infection should receive MenACWY vaccine because of the increased risk for meningococcal disease.

Outbreak of Serogroup C Meningococcal Disease Primarily Affecting Men Who Have Sex with Men - Southern California, 2016.

During March 4-August 11, 2016, 25 outbreak-associated cases of meningococcal disease, including two deaths (8% case-fatality ratio), were reported in Southern California. Twenty-four of the cases were caused by serogroup C Neisseria meningitidis (NmC) and one by N. meningitidis with an undetermined serogroup (Figure). On June 24, 2016, in response to this increase in NmC cases, primarily among men who have sex with men (MSM) in Los Angeles County, the city of Long Beach, and Orange County, the California Department of Public Health (CDPH) issued a press release and health advisory, declaring an outbreak of NmC in Southern California (1).