Publications by authors named "Nicola Klein"
Article Synopsis
- The text discusses the impact of pneumococcal conjugate vaccines (PCVs), specifically PCV10 and PCV13, on invasive pneumococcal disease (IPD) globally, highlighting how these vaccines have reduced the prevalence of disease caused by vaccine-type serotypes after extensive use.
- It describes the methodology of data collection from various surveillance sites, which aimed to evaluate IPD cases that occurred five years after the vaccines were implemented, focusing on different age groups for analysis.
- Findings indicate significant differences in serotype distribution between PCV10 and PCV13 sites; notably, certain serotypes, such as 19A and serotype 3, were prevalent in specific age groups, signaling ongoing challenges in controlling
Global impact of ten-valent and 13-valent pneumococcal conjugate vaccines on invasive pneumococcal disease in all ages (the PSERENADE project): a global surveillance analysis.
Lancet Infect Dis
December 2024
Background: Pneumococcal conjugate vaccines (PCVs) that are ten-valent (PCV10) and 13-valent (PCV13) became available in 2010. We evaluated their global impact on invasive pneumococcal disease (IPD) incidence in all ages.
Methods: Serotype-specific IPD cases and population denominators were obtained directly from surveillance sites using PCV10 or PCV13 in their national immunisation programmes and with a primary series uptake of at least 50%.
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.
Article Synopsis
- - In 2014, the PCV13 vaccine was recommended for adults 65 and older, aiming to reduce invasive pneumococcal disease (IPD), yet cases of serotype 3 lingered despite overall declines in other serotypes.
- - A study conducted from 2014 to 2020 within Kaiser Permanente Northern California evaluated the effectiveness of PCV13 in preventing IPD in this age group, analyzing over 610,000 participants.
- - The findings showed that the vaccine was 61.5% effective against PCV13-serotype IPD and 46.3% effective against serotype 3, highlighting the need for ongoing monitoring of vaccine impact on IPD across different serotypes. *
Background: The JYNNEOS vaccine (two doses given 28 days apart) was recommended in the United States for people at high risk of exposure to monkeypox virus during the 2022 mpox outbreak. Our objective was to assess the safety of JYNNEOS using two complementary epidemiologic methods.
Methods: This observational cohort included patients of eight large integrated healthcare organizations who received JYNNEOS.
Article Synopsis
- * The objective of the study was to assess the safety of the quadrivalent recombinant influenza vaccine (RIV4) compared to the quadrivalent standard-dose inactivated vaccine (SD-IIV4) among pregnant individuals and their infants.
- * Conducted by Kaiser Permanente Northern California, the observational study analyzed various pregnancy and birth outcomes, adjusting for factors like age and comorbidities, to determine the effects of RIV4 versus SD-IIV4 vaccinations during the 201
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.
View Article and Find Full Text PDFEffectiveness of the Original Monovalent and Bivalent COVID-19 Vaccines Against COVID-19-Associated Emergency Department and Urgent Care Encounters in Pregnant Persons Who Were Not Immunocompromised: VISION Network, June 2022-August 2023.
Open Forum Infect Dis
September 2024
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.
Background: Clostridioides difficile infection (CDI) causes substantial mortality and healthcare burden. We assessed the detoxified toxin-A/B PF-06425090 vaccine for primary CDI prevention.
Methods: This phase 3 observer-blinded study randomized (1:1) ≥50-year-olds at increased CDI risk (N = 17 535) to receive 3 PF-06425090 or placebo doses (0, 1, and 6 months).
Purpose: Vaccine-associated enhanced disease (VAED) is a theoretical concern with new vaccines, although trials of authorized vaccines against SARS-CoV-2 have not identified markers for VAED. The purpose of this study was to detect any signals for VAED among adults vaccinated against coronavirus disease 2019 (COVID-19).
Methods: In this cross-sectional study, we assessed COVID-19 severity as a proxy for VAED among 400 adults hospitalized for COVID-19 from March through October 2021 at eight US healthcare systems.
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.
Article Synopsis
- Limited evidence exists about how much wheezing in young children is linked to respiratory syncytial virus (RSV) infections in their early years.
- A study tracked 2-year-olds in 8 countries until they turned six, assessing wheeze occurrences and calculating the population attributable risk (PAR) for those with previous RSV lower respiratory tract infections.
- Results showed that children with RSV-LRTI had significantly higher incidences of wheezing, suggesting that preventing RSV infections in early childhood could reduce wheezing episodes in later years.
Article Synopsis
- Nine-valent human papillomavirus (9vHPV) vaccines can be given in two doses, and this study explores the effects of extending the time between doses beyond the typical 6 to 12 months.
- The study involved 146 adolescents who received their second 9vHPV dose between 12 to 53 months after the first dose, and results showed that antibody levels increased significantly after the second dose, with all participants showing a positive response a month later.
- Adverse events were mostly mild, such as injection site reactions, and no serious side effects were reported, suggesting that longer intervals between doses are safe and effective for the 9vHPV vaccination.
Ischemic Stroke After Bivalent COVID-19 Vaccination: Self-Controlled Case Series Study.
JMIR Public Health Surveill
June 2024
Article Synopsis
- The study analyzed the potential link between bivalent COVID-19 vaccination and the incidence of ischemic stroke, focusing on individuals aged 12 and older within a specific time frame in a large health care system.
- Results indicated no increased risk of ischemic stroke within 21 days of vaccination for either the Pfizer-BioNTech or Moderna vaccines across most groups, but a notable increase in risk was found for those under 65 who received the Pfizer-BioNTech vaccine alongside the influenza shot within 42 days.
- For individuals with a prior SARS-CoV-2 infection, the risk of stroke further increased, suggesting a need for close monitoring in these populations after vaccination.
Article Synopsis
- The study investigated the potential link between COVID-19 vaccination during pregnancy and the risk of stillbirth, addressing concerns of vaccine hesitancy among pregnant individuals.
- A matched case-control approach was used, analyzing data from 276 confirmed stillbirths and 822 live births to assess any significant associations with vaccination status.
- Results indicated no significant association between COVID-19 vaccination and stillbirth risk, regardless of vaccine type, number of doses, or timing of vaccination, suggesting that vaccination does not increase the risk of stillbirth in pregnant individuals.
Article Synopsis
- People with HIV (PWH) are more vulnerable to severe outcomes from COVID-19, but there’s limited knowledge on their vaccination rates and factors influencing their vaccine completion.
- A study was conducted to assess COVID-19 vaccination coverage among PWH and analyze the demographics, clinical aspects, and community influences affecting their vaccination completion.
- Results showed that 90.5% of PWH completed the primary vaccine series by the end of 2021, with prior influenza vaccination being a significant factor for both the initial series and additional doses, while uncontrolled HIV viremia negatively impacted vaccination rates.
Article Synopsis
- The U.S. COVID-19 vaccination program started in December 2020 and has played a crucial role in reducing illness and death caused by the virus, with safety monitoring being a key part of this effort.
- The government established multiple safety monitoring systems, utilizing both passive and active surveillance to track potential adverse events, especially focusing on vulnerable groups like pregnant individuals.
- The report highlights how systems worked together to quickly identify and manage issues like myocarditis after mRNA vaccinations, ensuring effective communication of safety data to healthcare providers and the public.
Interim Effectiveness of Updated 2023-2024 (Monovalent XBB.1.5) COVID-19 Vaccines Against COVID-19-Associated Hospitalization Among Adults Aged ≥18 Years with Immunocompromising Conditions - VISION Network, September 2023-February 2024.
MMWR Morb Mortal Wkly Rep
March 2024
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.
Background: The 20-valent pneumococcal conjugate vaccine (PCV20) was developed to extend pneumococcal disease protection beyond 13-valent PCV (PCV13).
Methods: This phase 3, double-blind study conducted in the United States/Puerto Rico evaluated PCV20 safety and immunogenicity. Healthy infants were randomized to receive a 4-dose series of PCV20 or PCV13 at 2, 4, 6 and 12-15 months old.
Objective: To assess the validity of electronic health record (EHR)-based influenza vaccination data among adults in a multistate network.
Methods: Following the 2018-2019 and 2019-2020 influenza seasons, surveys were conducted among a random sample of adults who did or did not appear influenza-vaccinated (per EHR data) during the influenza season. Participants were asked to report their influenza vaccination status; self-report was treated as the criterion standard.