Cost-effectiveness of an in-development adult-formulated pneumococcal vaccine in older US adults.

INTRODUCTION: CDC pneumococcal vaccination recommendations for older adults now include either 15- or 20-valent pneumococcal conjugate vaccine (PCV15/PCV20). However, an in-development 21-valent vaccine (PCV21), formulated based on adult pneumococcal disease epidemiology, could substantially increase coverage of disease-causing pneumococcal serotypes, particularly in Black older adults, who are at greater risk. The potential public health impact and cost-effectiveness of PCV21 compared to currently recommended vaccines in older adults is unclear. METHODS: A Markov decision model compared current pneumococcal vaccination recommendations to PCV21 use in Black and non-Black 65-year-old cohorts. CDC Active Bacterial Core surveillance data informed population and serotype-specific pneumococcal disease risk. Vaccine effectiveness was estimated using Delphi panel estimates and clinical trial data, with variation in sensitivity analyses. Potential indirect effects on adult disease from PCV15 childhood vaccination were examined. All model parameters were varied individually and collectively in sensitivity analyses. Scenarios with decreased PCV21 effectiveness and potential COVID-19 pandemic effects were also examined. RESULTS: In the Black cohort, the PCV21 strategy cost $88,478 per quality adjusted life-year (QALY) gained without and $97,952/QALY with childhood PCV15 indirect effects. PCV21 in the non-Black cohort cost $127,436/QALY gained without and $141,358/QALY with childhood PCV15 effects. Current recommendation strategies were economically unfavorable, regardless of population or indirect childhood vaccination effects. Results favoring PCV21 use were robust in sensitivity analyses and alternative scenarios. CONCLUSION: An in-development PCV21 vaccine would likely be economically and clinically favorable compared to currently recommended pneumococcal vaccines in older adults. While PCV21 was more favorable in Black cohort analyses, results for both Black and non-Black populations were economically reasonable, highlighting the potential importance of adult-specific pneumococcal vaccine formulations and, pending further investigation, potentially justifying a future general population recommendation for PCV21 use in older adults.

Prior SARS-CoV-2 infection and COVID-19 vaccine effectiveness against outpatient illness during widespread circulation of SARS-CoV-2 Omicron variant, US Flu VE network.

BACKGROUND: We estimated combined protection conferred by prior SARS-CoV-2 infection and COVID-19 vaccination against COVID-19-associated acute respiratory illness (ARI). METHODS: During SARS-CoV-2 Delta (B.1.617.2) and Omicron (B.1.1.529) variant circulation between October 2021 and April 2022, prospectively enrolled adult patients with outpatient ARI had respiratory and filter paper blood specimens collected for SARS-CoV-2 molecular testing and serology. Dried blood spots were tested for immunoglobulin-G antibodies against SARS-CoV-2 nucleocapsid (NP) and spike protein receptor binding domain antigen using a validated multiplex bead assay. Evidence of prior SARS-CoV-2 infection also included documented or self-reported laboratory-confirmed COVID-19. We used documented COVID-19 vaccination status to estimate vaccine effectiveness (VE) by multivariable logistic regression by prior infection status. RESULTS: Four hundred fifty-five (29%) of 1577 participants tested positive for SARS-CoV-2 infection at enrollment; 209 (46%) case-patients and 637 (57%) test-negative patients were NP seropositive, had documented previous laboratory-confirmed COVID-19, or self-reported prior infection. Among previously uninfected patients, three-dose VE was 97% (95% confidence interval [CI], 60%-99%) against Delta, but not statistically significant against Omicron. Among previously infected patients, three-dose VE was 57% (CI, 20%-76%) against Omicron; VE against Delta could not be estimated. CONCLUSIONS: Three mRNA COVID-19 vaccine doses provided additional protection against SARS-CoV-2 Omicron variant-associated illness among previously infected participants.

Blood Inflammatory Biomarkers Differentiate Inpatient and Outpatient Coronavirus Disease 2019 From Influenza.

Background: The ongoing circulation of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) poses a diagnostic challenge because symptoms of coronavirus disease 2019 (COVID-19) are difficult to distinguish from other respiratory diseases. Our goal was to use statistical analyses and machine learning to identify biomarkers that distinguish patients with COVID-19 from patients with influenza. Methods: Cytokine levels were analyzed in plasma and serum samples from patients with influenza and COVID-19, which were collected as part of the Centers for Disease Control and Prevention's Hospitalized Adult Influenza Vaccine Effectiveness Network (inpatient network) and the US Flu Vaccine Effectiveness (outpatient network). Results: We determined that interleukin (IL)-10 family cytokines are significantly different between COVID-19 and influenza patients. The results suggest that the IL-10 family cytokines are a potential diagnostic biomarker to distinguish COVID-19 and influenza infection, especially for inpatients. We also demonstrate that cytokine combinations, consisting of up to 3 cytokines, can distinguish SARS-CoV-2 and influenza infection with high accuracy in both inpatient (area under the receiver operating characteristics curve [AUC] = 0.84) and outpatient (AUC = 0.81) groups, revealing another potential screening tool for SARS-CoV-2 infection. Conclusions: This study not only reveals prospective screening tools for COVID-19 infections that are independent of polymerase chain reaction testing or clinical condition, but it also emphasizes potential pathways involved in disease pathogenesis that act as potential targets for future mechanistic studies.

Effect of mild COVID-19 on health-related quality of life.

Background: Little is known about the effects of a mild SARS-CoV-2 infection on health-related quality of life. Methods: This prospective observational study of symptomatic adults (18-87 years) who sought outpatient care for an acute respiratory illness, was conducted from 3/30/2020 to 4/30/2021. Participants completed the Short Form Health Survey (SF-12) at enrollment and 6-8 weeks later, to report their physical and mental health function levels as measured by the physical health and mental health composite scores (PHC and MHC, respectively). PHC and MHC scores for COVID-19 cases and non-COVID cases were compared using t-tests. Multivariable regression modeling was used to determine predictors of physical and mental health function at follow-up. Results: Of 2301 enrollees, 426 COVID-19 cases and 547 non-COVID cases completed both surveys. PHC improved significantly from enrollment to follow-up for both COVID-19 cases (5.4 ± 0.41; P < 0.001) and non-COVID cases (3.3 ± 0.32; P < 0.001); whereas MHC improved significantly for COVID-19 cases (1.4 ± 0.51; P < 0.001) and decreased significantly for non-COVID cases (-0.8 ± 0.37; P < 0.05). Adjusting for enrollment PHC, the most important predictors of PHC at follow-up included male sex (ß = 1.17; SE = 0.5; P = 0.021), having COVID-19 (ß = 1.99; SE = 0.54; P < 0.001); and non-white race (ß = -2.01; SE = 0.70; P = 0.004). Adjusting for enrollment MHC, the most important predictors of MHC at follow-up included male sex (ß = 1.92; SE = 0.63; P = 0.002) and having COVID-19 (ß = 2.42; SE = 0.67; P < 0.001). Conclusion: Both COVID-19 cases and non-COVID cases reported improved physical health function at 6-8 weeks' convalescence; whereas mental health function improved among COVID-19 cases but declined among non-COVID cases. Both physical and mental health functioning were significantly better among males with COVID-19 than females.

Relationship between Telework Experience and Presenteeism during COVID-19 Pandemic, United States, March-November 2020.

Persons with COVID-19-like illnesses are advised to stay home to reduce the spread of SARS-CoV-2. We assessed relationships between telework experience and COVID-19 illness with work attendance when ill. Adults experiencing fever, cough, or loss of taste or smell who sought healthcare or COVID-19 testing in the United States during March-November 2020 were enrolled. Adults with telework experience before illness were more likely to work at all (onsite or remotely) during illness (87.8%) than those with no telework experience (49.9%) (adjusted odds ratio 5.48, 95% CI 3.40-8.83). COVID-19 case-patients were less likely to work onsite (22.1%) than were persons with other acute respiratory illnesses (37.3%) (adjusted odds ratio 0.36, 95% CI 0.24-0.53). Among COVID-19 case-patients with telework experience, only 6.5% worked onsite during illness. Telework experience before illness gave mildly ill workers the option to work and improved compliance with public health recommendations to stay home during illness.

Agent-based model of the impact of higher influenza vaccine efficacy on seasonal influenza burden.

Introduction: Current influenza vaccines have limited effectiveness. COVID-19 vaccines using mRNA technology have demonstrated very high efficacy, suggesting that mRNA vaccines could be more effective for influenza. Several such influenza vaccines are in development. FRED, an agent-based modeling platform, was used to estimate the impact of more effective influenza vaccines on seasonal influenza burden. Methods: Simulations were performed using an agent-based model of influenza that included varying levels of vaccination efficacy (40-95 % effective). In some simulations, level of infectiousness and/or length of infectious period in agents with breakthrough infections was also decreased. Impact of increased and decreased levels of vaccine uptake were also modeled. Outcomes included number of symptomatic influenza cases estimated for the US. Results: Highly effective vaccines significantly reduced estimated influenza cases in the model. When vaccine efficacy was increased from 40 % to a maximum of 95 %, estimated influenza cases in the US decreased by 43 % to > 99 %. The base simulation (40 % efficacy) resulted in âˆ¼ 28 million total yearly cases in the US, while the most effective vaccine modeled (95 % efficacy) decreased estimated cases to âˆ¼ 22,000. Discussion: Highly effective vaccines could dramatically reduce influenza burden. Model estimates suggest that even modest increases in vaccine efficacy could dramatically reduce seasonal influenza disease burden.

Trends in HPV vaccine administration and HPV vaccine coverage in children by race/ethnicity and socioeconomic status during the COVID-19 pandemic in an integrated health care system in California.

BACKGROUND: We sought to evaluate the trends of HPV vaccination between 03/2019-09/2021 and whether the impact of the COVID pandemic on HPV vaccination varied by race/ethnicity and neighborhood deprivation index (NDI). METHODS: Electronic medical records at Kaiser Permanente Southern California were used to assess monthly volume of HPV vaccine doses administered among children aged 9-12.9yrs, and up-to-date coverage (% vaccinated) by age 13 between 03/2019-09/2021. Modified Poisson models were used to evaluate the interactions between race/ethnicity, NDI and the pandemic periods on HPV vaccine coverage. RESULTS: HPV vaccine doses administered in 2020/2021 have returned to the 2019 level after the initial drop. The average up-to-date coverage in 05/2021-09/2021 (54.8%) remained lower than the pre-pandemic level (58.5%). The associations between race/ethnicity, NDI and HPV vaccine coverage did not vary due to the pandemic. CONCLUSION: HPV vaccine promotion efforts are needed to address COVID-19 pandemic's lasting impact on HPV vaccination coverage.

Multiplex Detection of Antibody Landscapes to Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2)/Influenza/Common Human Coronaviruses Following Vaccination or Infection With SARS-CoV-2 and Influenza.

BACKGROUND: Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and influenza viruses continue to co-circulate, representing 2 major public health threats from respiratory infections with similar clinical presentations. SARS-CoV-2 and influenza vaccines can also now be co-administered. However, data on antibody responses to SARS-CoV-2 and influenza coinfection and vaccine co-administration remain limited. METHODS: We developed a 41-plex antibody immunity assay that can simultaneously characterize antibody landscapes to SARS-CoV-2/influenza/common human coronaviruses. We analyzed sera from 840 individuals (11-93 years), including sera from reverse transcription-polymerase chain reaction (RT-PCR)-confirmed SARS-CoV-2-positive (n = 218) and -negative (n = 120) cases, paired sera from SARS-CoV-2 vaccination (n = 29) and infection (n = 11), and paired sera from influenza vaccination (n = 56) and RT-PCR-confirmed influenza infection (n = 158) cases. Last, we analyzed sera collected from 377 individuals who exhibited acute respiratory illness (ARI) in 2020. RESULTS: This 41-plex assay has high sensitivity and specificity in detecting SARS-CoV-2 infections. It differentiated SARS-CoV-2 vaccination (antibody responses only to spike protein) from infection (antibody responses to both spike and nucleoprotein). No cross-reactive antibodies were induced to SARS-CoV-2 from influenza vaccination and infection, and vice versa, suggesting no interaction between SARS-CoV-2 and influenza antibody responses. However, cross-reactive antibodies were detected between spike proteins of SARS-CoV-2 and common human coronaviruses that were removed by serum adsorption. Among 377 individuals who exhibited ARI in 2020, 129 were influenza positive; none had serological evidence of SARS-CoV-2/influenza coinfections. CONCLUSIONS: Multiplex detection of antibody landscapes can provide in-depth analysis of the antibody protective immunity to SARS-CoV-2 in the context of other respiratory viruses, including influenza.

Trends in HPV vaccine administration and HPV vaccine coverage in children by race/ethnicity and socioeconomic status during the COVID-19 pandemic in an integrated health care system in California

Background We sought to evaluate the trends of HPV vaccination between 03/2019-09/2021 and whether the impact of the COVID pandemic on HPV vaccination varied by race/ethnicity and neighborhood deprivation index (NDI). Methods Electronic medical records at Kaiser Permanente Southern California were used to assess monthly volume of HPV vaccine doses administered among children aged 9-12.9yrs, and up-to-date coverage (% vaccinated) by age 13 between 03/2019-09/2021. Modified Poisson models were used to evaluate the interactions between race/ethnicity, NDI and the pandemic periods on HPV vaccine coverage. Results HPV vaccine doses administered in 2020/2021 have returned to the 2019 level after the initial drop. The average up-to-date coverage in 05/2021-09/2021 (54.8%) remained lower than the pre-pandemic level (58.5%). The associations between race/ethnicity, NDI and HPV vaccine coverage did not vary due to the pandemic. Conclusion HPV vaccine promotion efforts are needed to address COVID-19 pandemic’s lasting impact on HPV vaccination coverage.

Population-based hospitalization burden estimates for respiratory viruses, 2015-2019.

BACKGROUND: Acute respiratory infections (ARIs) result in millions of illnesses and hundreds of thousands of hospitalizations annually in the United States. The responsible viruses include influenza, parainfluenza, human metapneumovirus, coronaviruses, respiratory syncytial virus (RSV), and human rhinoviruses. This study estimated the population-based hospitalization burden of those respiratory viruses (RVs) over 4 years, from July 1, 2015 to June 30, 2019, among adults ≥18 years of age for Allegheny County (Pittsburgh), Pennsylvania. METHODS: We used population-based statewide hospital discharge data, health system electronic medical record (EMR) data for RV tests, census data, and a published method to calculate burden. RESULTS: Among 26,211 eligible RV tests, 67.6% were negative for any virus. The viruses detected were rhinovirus/enterovirus (2552; 30.1%), influenza A (2,299; 27.1%), RSV (1082; 12.7%), human metapneumovirus (832; 9.8%), parainfluenza (601; 7.1%), influenza B (565; 6.7%), non-SARS-CoV-2 coronavirus (420; 4.9% 1.5 years of data available), and adenovirus (136; 1.6%). Most tests were among female (58%) and White (71%) patients with 60% of patients ≥65 years, 24% 50-64 years, and 16% 18-49 years. The annual burden ranged from 137-174/100,000 population for rhinovirus/enterovirus; 99-182/100,000 for influenza A; and 56-81/100,000 for RSV. Among adults <65 years, rhinovirus/enterovirus hospitalization burden was higher than influenza A; whereas the reverse was true for adults ≥65 years. RV hospitalization burden increased with increasing age. CONCLUSIONS: These virus-specific ARI population-based hospital burden estimates showed significant non-influenza burden. These estimates can serve as the basis for several areas of research that are essential for setting funding priorities and guiding public health policy.

SARS-CoV-2 Antibody Response Is Associated with Age and Body Mass Index in Convalescent Outpatients.

COVID-19 has had an unprecedented global impact on human health. Understanding the Ab memory responses to infection is one tool needed to effectively control the pandemic. Among 173 outpatients who had virologically confirmed SARS-CoV-2 infection, we evaluated serum Ab concentrations, microneutralization activity, and enumerated SARS-CoV-2-specific B cells in convalescent human blood specimens. Serum Ab concentrations were variable, allowing for stratification of the cohort into high and low responders. Neither participant sex, the timing of blood sampling following the onset of illness, nor the number of SARS-CoV-2 spike protein-specific B cells correlated with serum Ab concentration. Serum Ab concentration was positively associated with microneutralization activity and participant age, with participants under the age of 30 showing the lowest Ab level. These data suggest that young adult outpatients did not generate as robust Ab memory, compared with older adults. Body mass index was also positively correlated with serum Ab levels. Multivariate analyses showed that participant age and body mass index were independently associated with Ab levels. These findings have direct implications for public health policy and current vaccine efforts. Knowledge gained regarding Ab memory following infection will inform the need for vaccination in those previously infected and allow for a better approximation of population-wide protective immunity.

Impact of Low Rates of Influenza on Next-Season Influenza Infections.

INTRODUCTION: Interventions to curb the spread of COVID-19 during the 2020-2021 influenza season essentially eliminated influenza during that season. Given waning antibody titers over time, future residual population immunity against influenza will be reduced. The implication for the subsequent 2021-2022 influenza season is unknown. METHODS: An agent-based model of influenza implemented in the Framework for Reconstructing Epidemiological Dynamics simulation platform was used to estimate cases and hospitalizations over 2 successive influenza seasons. The impact of reduced residual immunity owing to protective measures in the first season was estimated over varying levels of similarity (cross-immunity) between influenza strains over the seasons. RESULTS: When cross-immunity between first- and second-season strains was low, a decreased first season had limited impact on second-season cases. High levels of cross-immunity resulted in a greater impact on the second season. This impact was modified by the transmissibility of strains in the 2 seasons. The model estimated a possible increase of 13.52%-46.95% in cases relative to that in a normal season when strains have the same transmissibility and 40%-50% cross-immunity in a season after a very low one. CONCLUSIONS: Given the light 2020-2021 influenza season, cases may increase by as much as 50% in 2021-2022, although the increase could be much less, depending on cross-immunity from past infection and transmissibility of strains. Enhanced vaccine coverage or continued interventions to reduce transmission could reduce this high season. Young children may have a higher risk in 2021-2022 owing to limited exposure to infection in the previous year.

Vaccine effectiveness against COVID-19 among symptomatic persons aged ≥12 years with reported contact with COVID-19 cases, February-September 2021.

BACKGROUND: Individuals in contact with persons with COVID-19 are at high risk of developing COVID-19; protection offered by COVID-19 vaccines in the context of known exposure is poorly understood. METHODS: Symptomatic outpatients aged ≥12 years reporting acute onset of COVID-19-like illness and tested for SARS-CoV-2 between February 1 and September 30, 2021 were enrolled. Participants were stratified by self-report of having known contact with a COVID-19 case in the 14 days prior to illness onset. Vaccine effectiveness was evaluated using the test-negative study design and multivariable logistic regression. RESULTS: Among 2229 participants, 283/451 (63%) of those reporting contact and 331/1778 (19%) without known contact tested SARS-CoV-2-positive. Adjusted vaccine effectiveness was 71% (95% confidence interval [CI], 49%-83%) among fully vaccinated participants reporting a known contact versus 80% (95% CI, 72%-86%) among those with no known contact (p-value for interaction = 0.2). CONCLUSIONS: This study contributes to growing evidence of the benefits of vaccinations in preventing COVID-19 and support vaccination recommendations and the importance of efforts to increase vaccination coverage.

Estimating the Impact of Low Influenza Activity in 2020 on Population Immunity and Future Influenza Seasons in the United States.

BACKGROUND: Influenza activity in the 2020-2021 season was remarkably low, likely due to implementation of public health preventive measures such as social distancing, mask wearing, and school closure. With waning immunity, the impact of low influenza activity in the 2020-2021 season on the following season is unknown. METHODS: We built a multistrain compartmental model that captures immunity over multiple influenza seasons in the United States. Compared with the counterfactual case, where influenza activity remained at the normal level in 2020-2021, we estimated the change in the number of hospitalizations when the transmission rate was decreased by 20% in 2020-2021. We varied the level of vaccine uptake and effectiveness in 2021-2022. We measured the change in population immunity over time by varying the number of seasons with lowered influenza activity. RESULTS: With the lowered influenza activity in 2020-2021, the model estimated 102 000 (95% CI, 57 000-152 000) additional hospitalizations in 2021-2022, without changes in vaccine uptake and effectiveness. The estimated changes in hospitalizations varied depending on the level of vaccine uptake and effectiveness in the following year. Achieving a 50% increase in vaccine coverage was necessary to avert the expected increase in hospitalization in the next influenza season. If the low influenza activity were to continue over several seasons, population immunity would remain low during those seasons, with 48% of the population susceptible to influenza infection. CONCLUSIONS: Our study projected a large compensatory influenza season in 2021-2022 due to a light season in 2020-2021. However, higher influenza vaccine uptake would reduce this projected increase in influenza.

Messenger RNA Vaccine Effectiveness Against Coronavirus Disease 2019 Among Symptomatic Outpatients Aged ≥16 Years in the United States, February-May 2021.

Evaluations of vaccine effectiveness (VE) are important to monitor as coronavirus disease 2019 (COVID-19) vaccines are introduced in the general population. Research staff enrolled symptomatic participants seeking outpatient medical care for COVID-19-like illness or severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) testing from a multisite network. VE was evaluated using the test-negative design. Among 236 SARS-CoV-2 nucleic acid amplification test-positive and 576 test-negative participants aged ≥16 years, the VE of messenger RNA vaccines against COVID-19 was 91% (95% confidence interval, 83%-95%) for full vaccination and 75% (55%-87%) for partial vaccination. Vaccination was associated with prevention of most COVID-19 cases among people seeking outpatient medical care.

Should older adult pneumococcal vaccination recommendations change due to decreased vaccination in children during the pandemic? A cost-effectiveness analysis.

BACKGROUND: The COVID-19 pandemic is causing declines in childhood immunization rates. We examined potential COVID-19-related changes in pediatric 13-valent pneumococcal conjugate vaccine (PCV13) use, subsequent impact on childhood and adult pneumococcal disease rates, and how those changes might affect the favorability of PCV13 use in non-immunocompromised adults aged ≥65 years. METHODS: A Markov model estimated pediatric disease resulting from decreased PCV13 use in children aged <5 years; absolute decreases from 10 to 50% for 1-2 years duration were examined, assuming no catch-up vaccination and that decreased vaccination led to proportionate increases in PCV13 serotype pneumococcal disease in children and seniors. Integrating pediatric model output into a second Markov model examining 65-year-olds, we estimated the cost effectiveness of older adult pneumococcal vaccination strategies while accounting for potential epidemiologic changes from decreased pediatric vaccination. RESULTS: One year of 10-50% absolute decreases in PCV13 use in <5-year-olds increased pneumococcal disease by an estimated 4-19% in seniors; 2 years of decreased use increased senior rates by 8-38%. In seniors, a >53% increase in pneumococcal disease was required to favor PCV13 use in non-immunocompromised seniors at a $200,000 per quality-adjusted life-year gained threshold, which corresponded to absolute decreases in pediatric PCV13 vaccination of >50% over a 2-year period. In sensitivity analyses, senior PCV13 vaccination was unfavorable if absolute decreases in pediatric PCV13 receipt were within plausible ranges, despite model assumptions favoring PCV13 use in seniors. CONCLUSION: COVID-19-related decreases in pediatric PCV13 use would need to be both substantial and prolonged to make heightened PCV13 use in non-immunocompromised seniors economically favorable.

Helping patients with ethical concerns about COVID-19 vaccines in light of fetal cell lines used in some COVID-19 vaccines.

Many persons with religious convictions report hesitancy about COVID-19 vaccines, in part due to ethical concerns that fetal cell lines are used in the development of certain vaccines. The issue of abortion is contentious and, given the potential impact on COVID-19 vaccination, it is important for clinicians to be aware of this issue, whatever their personal beliefs. I provide four responses that clinicians may offer their patients: 1) Ethical analyses of moral complicity and COVID vaccines. 2) Altruism and protecting others from a virus that is often transmitted while asymptomatic or pre-symptomatic. 3) Religious texts and many religious leaders support prevention and, therefore, vaccination. 4) Administration of vaccines not developed in fetal cell lines. Although I wish for all my patients to be vaccinated, I respect their autonomy to make the choice to be or not to be vaccinated and understand that many have a deep regard for fetal life.

Coronavirus disease 2019 (COVID-19) Versus Influenza in Hospitalized Adult Patients in the United States: Differences in Demographic and Severity Indicators.

BACKGROUND: Novel coronavirus disease 2019 (COVID-19) is frequently compared with influenza. The Hospitalized Adult Influenza Vaccine Effectiveness Network (HAIVEN) conducts studies on the etiology and characteristics of U.S. hospitalized adults with influenza. It began enrolling patients with COVID-19 hospitalizations in March 2020. Patients with influenza were compared with those with COVID-19 in the first months of the U.S. epidemic. METHODS: Adults aged ≥ 18 years admitted to hospitals in 4 sites with acute respiratory illness were tested by real-time reverse transcription polymerase chain reaction for influenza and severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the virus causing COVID-19. Demographic and illness characteristics were collected for influenza illnesses during 3 seasons 2016-2019. Similar data were collected on COVID-19 cases admitted before June 19, 2020. RESULTS: Age groups hospitalized with COVID-19 (n = 914) were similar to those admitted with influenza (n = 1937); 80% of patients with influenza and 75% of patients with COVID-19 were aged ≥50 years. Deaths from COVID-19 that occurred in younger patients were less often related to underlying conditions. White non-Hispanic persons were overrepresented in influenza (64%) compared with COVID-19 hospitalizations (37%). Greater severity and complications occurred with COVID-19 including more ICU admissions (AOR = 15.3 [95% CI: 11.6, 20.3]), ventilator use (AOR = 15.6 [95% CI: 10.7, 22.8]), 7 additional days of hospital stay in those discharged alive, and death during hospitalization (AOR = 19.8 [95% CI: 12.0, 32.7]). CONCLUSIONS: While COVID-19 can cause a respiratory illness like influenza, it is associated with significantly greater severity of illness, longer hospital stays, and higher in-hospital deaths.

Effectiveness of Pfizer-BioNTech and Moderna Vaccines Against COVID-19 Among Hospitalized Adults Aged ≥65 Years - United States, January-March 2021.

Adults aged ≥65 years are at increased risk for severe outcomes from COVID-19 and were identified as a priority group to receive the first COVID-19 vaccines approved for use under an Emergency Use Authorization (EUA) in the United States (1-3). In an evaluation at 24 hospitals in 14 states,* the effectiveness of partial or full vaccination† with Pfizer-BioNTech or Moderna vaccines against COVID-19-associated hospitalization was assessed among adults aged ≥65 years. Among 417 hospitalized adults aged ≥65 years (including 187 case-patients and 230 controls), the median age was 73 years, 48% were female, 73% were non-Hispanic White, 17% were non-Hispanic Black, 6% were Hispanic, and 4% lived in a long-term care facility. Adjusted vaccine effectiveness (VE) against COVID-19-associated hospitalization among adults aged ≥65 years was estimated to be 94% (95% confidence interval [CI] = 49%-99%) for full vaccination and 64% (95% CI = 28%-82%) for partial vaccination. These findings are consistent with efficacy determined from clinical trials in the subgroup of adults aged ≥65 years (4,5). This multisite U.S. evaluation under real-world conditions suggests that vaccination provided protection against COVID-19-associated hospitalization among adults aged ≥65 years. Vaccination is a critical tool for reducing severe COVID-19 in groups at high risk.

Clinical Symptoms Among Ambulatory Patients Tested for SARS-CoV-2.

We compared symptoms and characteristics of 4961 ambulatory patients with and without laboratory-confirmed severe acute respiratory syndrome coronavirus 2 infection. Findings indicate that clinical symptoms alone would be insufficient to distinguish between coronavirus disease 2019 and other respiratory infections (eg, influenza) and/or to evaluate the effects of preventive interventions (eg, vaccinations).