Publications by authors named "Zerbo O"
Background: The 2023-2024 influenza season had predominant influenza A(H1N1)pdm09 virus activity, but A(H3N2) and B viruses co-circulated. Seasonal influenza vaccine strains were well-matched to these viruses.
Methods: Using health care encounters data from health systems in 8 states, we evaluated influenza vaccine effectiveness (VE) against influenza-associated medical encounters from October 2023-April 2024.
Incidence and Risk of Coronavirus Disease 2019 Hospitalization Among Unvaccinated Children.
Influenza Other Respir Viruses
October 2024
Objectives: The aim of this study is to determine the incidence and risk factors associated with COVID-19 hospitalization among unvaccinated children.
Methods: Children aged 0- < 18 years, members of Kaiser Permanente Northern California (KPNC), were followed from March 1, 2020, until the earliest occurrence of: chart-confirmed COVID-19 hospitalization, disenrollment from KPNC, age 18 years, receipt of COVID-19 vaccine, death, or study end (December 31, 2022). We calculated the incidence rate of hospitalization by SARS-CoV-2 variant period and by age group.
Background: Respiratory syncytial virus vaccines first recommended for use during 2023 were efficacious against lower respiratory tract disease in clinical trials. Limited real-world data regarding respiratory syncytial virus vaccine effectiveness are available. To inform vaccine policy and address gaps in evidence from the clinical trials, we aimed to assess the effectiveness against respiratory syncytial virus-associated hospitalisations and emergency department encounters among adults aged at least 60 years.
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- A study investigates the effects of receiving seasonal influenza vaccinations during two successive pregnancies on adverse birth outcomes, focusing on differences based on interpregnancy intervals and vaccine types (quadrivalent or trivalent).
- Data was collected from a large cohort of individuals with at least two singleton live births between 2004 and 2018, using information from the Vaccine Safety Datalink.
- The study analyzed risks of complications like preeclampsia, placental issues, and preterm birth among vaccinated and unvaccinated populations, finding that the majority of participants received vaccinations in both pregnancies.
Article Synopsis
- Pregnant individuals are at a higher risk for severe COVID-19, leading to current guidelines recommending updated vaccinations for everyone aged 6 months and older, regardless of pregnancy status.
- A study evaluated COVID-19 vaccine effectiveness among pregnant people aged 18 to 45 from June 2022 to August 2023, finding that vaccine effectiveness during pregnancy was 52%, compared to 28% when vaccination was received less than 6 months before pregnancy and only 6% when received more than 6 months prior.
- The findings suggest that pregnant individuals should remain up-to-date with recommended COVID-19 vaccinations for better protection against the virus.
Article Synopsis
- A study investigated whether the MenB-4C vaccine, designed for meningococcal serogroup B, could protect against gonorrhea in individuals aged 15-30 years in Northern California from 2016-2021.
- Researchers analyzed health records to compare the prevalence of gonococcal and chlamydial infections among vaccinated and unvaccinated individuals, finding that MenB-4C vaccination reduced the risk of gonococcal mono-infections by 23% in a limited model.
- However, this protective effect disappeared when adjusting for additional confounding factors, and no protection against co-infections of gonorrhea and chlamydia was found.
Purpose: The COVID-19 pandemic impacted testing and incidence of sexually transmitted infections (STIs), with some studies showing uneven effects across sociodemographic groups. We aim to determine whether rates of gonorrhea and chlamydia testing and infections were affected by the pandemic, overall and by subgroups, defined by sociodemographic factors and comorbidities.
Methods: We conducted a retrospective cohort study from January 1, 2016, through December 31, 2022, among adolescents and young adults ages 15-29 years within Kaiser Permanente Northern California (KPNC).
Article Synopsis
- The 2022-2023 influenza season in the U.S. experienced high hospitalization rates and early influenza activity, primarily driven by A(H3N2) viruses, with some A(H1N1)pdm09 cases.
- A study using the test-negative design assessed the effectiveness of the influenza vaccine by comparing cases of influenza-positive patients to those who tested negative among adults with respiratory illness from October 2022 to March 2023.
- The results showed moderate vaccine effectiveness of 44% for emergency department visits and 35% for hospitalizations, indicating that vaccination helps reduce the impact of influenza during a challenging season with other circulating respiratory viruses.
Importance: COVID-19 vaccination is recommended throughout pregnancy to prevent pregnancy complications and adverse birth outcomes associated with COVID-19 disease. To date, data on birth defects after first-trimester vaccination are limited.
Objective: To evaluate the associated risks for selected major structural birth defects among live-born infants after first-trimester receipt of a messenger RNA (mRNA) COVID-19 vaccine.
Article Synopsis
- COVID-19 vaccinations are effective in preventing severe illness and death but their impact on post-COVID conditions (PCC) is less understood, prompting a study to evaluate this association.
- The study analyzed electronic health records from over 161,000 vaccinated and unvaccinated COVID-19 patients from multiple healthcare systems, focusing on new diagnoses of PCC within six months after infection.
- Results showed that vaccinated individuals had a lower risk of several PCC categories, especially sensory and circulatory issues, while mental health disorders had a slightly higher risk in vaccinated individuals, indicating that vaccination may help reduce long-term COVID-19 consequences.
Article Synopsis
- - This study aimed to assess whether getting vaccinated with mRNA COVID-19 vaccines during pregnancy affects the risk of adverse pregnancy outcomes like preterm birth and small-for-gestational age infants.
- - Researchers analyzed data from over 55,000 individuals with live singleton pregnancies and found that 42.3% received one or two doses of the vaccine, with the vaccination rate varying across maternal demographics.
- - The results indicated that vaccinated individuals had a lower risk of preterm birth compared to unvaccinated individuals, but the vaccination did not significantly impact the risks of small-for-gestational age infants, gestational diabetes, gestational hypertension, or preeclampsia.
Article Synopsis
- The CDC recommended the updated 2023-2024 COVID-19 vaccination (monovalent XBB.1.5) for everyone aged 6 months and older to help prevent severe disease caused by COVID-19.
- For individuals with immunocompromising conditions, additional vaccine doses may be needed due to their increased risk of severe illness and potentially weaker vaccine responses.
- Vaccine effectiveness for the updated dose was about 38% for hospitalized adults with immunocompromising conditions 7-59 days post-vaccination and 34% between 60-119 days, but only 18% of this high-risk group had received the updated vaccine.
Article Synopsis
- A study assessed the real-world effectiveness of a 2-dose recombinant zoster vaccine (RZV), previously shown to be 97% effective in clinical trials, against herpes zoster (HZ) in adults aged 50 and older.
- The findings revealed that the vaccine's effectiveness was 76% after two doses, with minimal decline over four years, while the effectiveness after one dose was 64% initially but decreased significantly over time.
- The study highlights the importance of receiving both doses to maintain better protection against HZ, especially considering some individuals may have reduced effectiveness due to prior corticosteroid use.
Impact of the COVID-19 Pandemic on Health Care Utilization in the Vaccine Safety Datalink: Retrospective Cohort Study.
JMIR Public Health Surveill
January 2024
Background: Understanding the long-term impact of the COVID-19 pandemic on health care utilization is important to health care organizations and policy makers for strategic planning, as well as to researchers when designing studies that use observational electronic health record data during the pandemic period.
Objective: This study aimed to evaluate the changes in health care utilization across all care settings among a large, diverse, and insured population in the United States during the COVID-19 pandemic.
Methods: We conducted a retrospective cohort study within 8 health care organizations participating in the Vaccine Safety Datalink Project using electronic health record data from members of all ages from January 1, 2017, to December 31, 2021.
Article Synopsis
- The 2022-2023 influenza season in the U.S. saw the highest rate of pediatric hospitalization since 2010-2011, primarily caused by Influenza A/H3N2 infections.
- A study analyzed nearly 45,000 emergency department visits and hospitalizations for children aged 6 months to 17 years, focusing on the effectiveness of the influenza vaccine using a comparison between vaccinated and unvaccinated patients.
- Results showed that vaccination significantly reduced the risk of influenza-related emergency visits and hospitalizations by approximately 40-48%, emphasizing the importance of flu shots in preventing severe illness in kids and teens.
Article Synopsis
- SARS-CoV-2 infection during pregnancy can lead to varying severity of COVID-19, including hospitalization and death, making vaccination crucial.
- The study focused on evaluating the effectiveness of mRNA COVID-19 vaccines in pregnant individuals, specifically looking at outcomes like hospitalization and infection rates across different virus variants and time since vaccination.
- Among 57,688 pregnant individuals, 28% were vaccinated; the results indicated a 91% effectiveness against hospitalization within 150 days post-vaccination that declined to 48% after 150 days.
We investigated whether unvaccinated pregnant persons cluster geographically and determined factors associated with being unvaccinated using spatial and multivariate logistic regression analyses. Pregnant persons with deliveries from December 15, 2020, through September 30, 2022, at Kaiser Permanente Northern California were included. Of the 85,852 pregnant persons in the study, 46.
View Article and Find Full Text PDFBackground: The epidemiology of coronavirus disease 2019 (COVID-19) continues to develop with emerging variants, expanding population-level immunity, and advances in clinical care. We describe changes in the clinical epidemiology of COVID-19 hospitalizations and risk factors for critical outcomes over time.
Methods: We included adults aged ≥18 years from 10 states hospitalized with COVID-19 June 2021-March 2023.
Article Synopsis
- A study examined influenza vaccination coverage among pregnant people in the U.S. from the 2016-2017 to 2021-2022 seasons, revealing trends among different demographics.
- Coverage rose from 63.0% in 2016-2017 to a peak of 71.0% in 2019-2020 but dropped significantly to 56.4% during the 2021-2022 season post-COVID-19 pandemic.
- The research highlighted that the lowest vaccination rates were consistently among pregnant individuals aged 18-24 and non-Hispanic Black individuals, emphasizing the need for targeted outreach to increase vaccination coverage.
Article Synopsis
- - On June 19, 2022, the FDA approved mRNA COVID-19 vaccines for young children based on safety and efficacy data from trials, with Pfizer-BioNTech for ages 6 months-4 years and Moderna for ages 6 months-5 years.
- - The CDC updated vaccine recommendations on December 9, 2022, including the use of bivalent vaccines for children aged 6 months and older, after assessing their effectiveness against hospital visits for COVID-19-like illness.
- - Effectiveness of two Moderna doses was found to be 29%, while three Pfizer doses showed 43% effectiveness; however, children who received at least one bivalent dose had an 80% effectiveness in preventing
Article Synopsis
- Immunocompromised (IC) individuals face a higher risk of severe COVID-19 and have reduced vaccine effectiveness compared to non-immunocompromised (non-IC) individuals.
- A study analyzed emergency department visits and hospitalizations among IC and non-IC adults, finding that vaccine effectiveness was significantly lower in IC patients, particularly for those who received 3 doses of mRNA vaccines or 1-2 doses of viral-vector vaccines.
- Despite some protection from vaccines, the results indicate a pressing need for additional safeguards for IC adults, especially transplant recipients who showed the lowest vaccine effectiveness.
Article Synopsis
- The study examines the safety of simultaneous vaccination (SV) with COVID-19 vaccines and other vaccines, analyzing data from the Vaccine Safety Datalink for those aged 5 and older.
- The findings show that SV with COVID-19 vaccines was infrequent, with only about 0.7% for the first dose and 0.3% for the second dose, primarily including vaccines like influenza and HPV.
- Overall, while most health outcomes following SV were rare and similar to those who didn't receive SV, there were some statistically significant increases in rates of specific conditions like appendicitis and Bell's palsy after certain doses.
Article Synopsis
- A study involving over 80,000 pregnant individuals found that receiving a COVID-19 mRNA booster shot did not increase the risk of serious health issues like thrombocytopenia, myocarditis, or stroke shortly after vaccination.
- However, the booster was linked to a higher incidence of mild symptoms such as malaise or fatigue within the first week, and lymph node swelling or inflammation in the following weeks.
- Overall, the results align with previous studies and suggest that it's safe for pregnant people to receive the COVID-19 booster.