Publications by authors named "Sy L"

This retrospective cohort study evaluated the comparative vaccine effectiveness (cVE) of licensed standard-dose cell-based versus egg-based influenza vaccines in preventing influenza hospitalization among adults 18-64 years during the 2022-2023 season. The cohort included eligible Kaiser Permanente Southern California members who received ≥ 1 dose of influenza vaccine (n = 848,334). The adjusted cVE against influenza hospitalization was -10.

View Article and Find Full Text PDF

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.

View Article and Find Full Text PDF
Article Synopsis
  • 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.
View Article and Find Full Text PDF
Article Synopsis
  • A study developed and validated a natural language processing (NLP) algorithm to identify postherpetic neuralgia (PHN) from unstructured electronic health records (EHRs), aiming to improve accuracy compared to traditional diagnosis codes and prescription data.
  • The research involved reviewing EHRs from a large health care system and comparing the NLP's performance with code-based methods by analyzing sensitivity, specificity, and other statistical measures.
  • Results showed the NLP algorithm had high sensitivity (90.9%) and specificity (98.5%), with notable advantages in identifying PHN cases compared to code-based methods, which exhibited much lower sensitivity (52.7%-61.8%).
View Article and Find Full Text PDF
Article Synopsis
  • The study examined the pregnancy outcomes of adults who received the HepB-CpG vaccine or the traditional HepB-alum vaccine shortly before or during pregnancy at Kaiser Permanente Southern California.* -
  • Among the individuals studied, those who received HepB-CpG had a higher live birth rate (84%) compared to HepB-alum recipients (74%), with lower spontaneous abortion rates for the HepB-CpG group (7% vs. 17%).* -
  • No major birth defects were reported in either group, suggesting that HepB-CpG does not pose additional risks for pregnancy outcomes compared to HepB-alum.*
View Article and Find Full Text PDF
Article Synopsis
  • Influenza significantly impacts older adults, necessitating updated data on vaccine effectiveness within this group.
  • A study at Kaiser Permanente Southern California assessed the comparative vaccine effectiveness of high-dose, adjuvanted, and standard-dose cell-based influenza vaccines against the standard-dose egg-based vaccine among individuals aged 65 and older.
  • Results indicated that both high-dose and adjuvanted vaccines offered better protection against influenza-related medical encounters and hospitalization compared to the standard-dose egg-based vaccine during the 2022-2023 flu season.
View Article and Find Full Text PDF
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.
View Article and Find Full Text PDF
Article Synopsis
  • The study examines the safety of 2-dose mRNA vaccines, focusing on serious adverse events (SAEs) during the risk period after the first dose and how they might affect the safety evaluation for the second dose.
  • Researchers developed two new methods, propensity score SCCS (PS-SCCS) and partitioned SCCS (P-SCCS), which provided unbiased estimates of the relative incidence of myocarditis/pericarditis after vaccination, unlike standard SCCS which overestimated risk after the second dose.
  • Findings indicated that mRNA vaccines, particularly after the second dose, are linked with increased risks of myocarditis/pericarditis in individuals aged 12-39.
View Article and Find Full Text PDF
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.
View Article and Find Full Text PDF
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.
View Article and Find Full Text PDF

Both music and language are found in all known human societies, yet no studies have compared similarities and differences between song, speech, and instrumental music on a global scale. In this Registered Report, we analyzed two global datasets: (i) 300 annotated audio recordings representing matched sets of traditional songs, recited lyrics, conversational speech, and instrumental melodies from our 75 coauthors speaking 55 languages; and (ii) 418 previously published adult-directed song and speech recordings from 209 individuals speaking 16 languages. Of our six preregistered predictions, five were strongly supported: Relative to speech, songs use (i) higher pitch, (ii) slower temporal rate, and (iii) more stable pitches, while both songs and speech used similar (iv) pitch interval size and (v) timbral brightness.

View Article and Find Full Text PDF
Article Synopsis
  • Emerging SARS-CoV-2 sublineages continue to pose a risk for serious COVID-19 disease, particularly as many individuals haven’t been vaccinated in over a year.
  • A study evaluated the effectiveness of the mRNA-1273 bivalent vaccine against these circulating sublineages by analyzing confirmed cases and matching them to controls, revealing a decline in vaccine effectiveness over time.
  • The findings suggest that periodic revaccination with updated vaccines could be necessary to lower COVID-19-related health issues as the effectiveness of existing vaccines decreases against new variants.
View Article and Find Full Text PDF

We evaluated the vaccine effectiveness (VE) of two doses of recombinant zoster vaccine (RZV) against herpes zoster (HZ) and postherpetic neuralgia (PHN) in Chinese adults at Kaiser Permanente Southern California (KPSC). Chinese KPSC members were identified based on self-reported ethnicity or self-reported preferred spoken/written language. Those aged ≥50 years who received two doses of RZV 4 weeks to ≤ 6 months apart were matched 1:4 to RZV unvaccinated Chinese members and followed through June 2022; second doses were accrued 6/1/2018-12/31/2020.

View Article and Find Full Text PDF
Article Synopsis
  • A study re-evaluated mortality risks associated with COVID-19 vaccinations using a modified self-controlled case series design to minimize confounding biases.
  • Researchers analyzed death data from vaccinated and unvaccinated individuals, focusing on non-COVID-19 mortality and specific cardiac-related deaths within set observation periods.
  • Results for Pfizer-BioNTech showed reduced mortality risks for all outcomes, while Moderna and Janssen also indicated low risks, although some results for Moderna had confidence intervals that included 1, suggesting uncertainty in the estimates.
View Article and Find Full Text PDF

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.

View Article and Find Full Text PDF

Background: Bivalent mRNA COVID-19 vaccines were developed to provide protection against the original SARS-CoV-2 strain and Omicron BA.4/BA.5 variants, but uptake in the United States has been low.

View Article and Find Full Text PDF

Background: COVID-19 vaccination is crucial in combating the COVID-19 pandemic. Messenger RNA COVID-19 vaccines were initially authorized as a 2-dose primary series and have been widely used in the United States; completing the 2-dose primary series offers protection against infection, severe illness, and death. Understanding the risk factors for not completing the 2-dose primary series is critical to evaluate COVID-19 vaccination programs and promote completion of the 2-dose primary series.

View Article and Find Full Text PDF
Article Synopsis
  • The bivalent mRNA-1273 COVID-19 vaccine, which targets both the original virus and the Omicron BA.4/BA.5 variants, has been authorized to enhance protection against COVID-19.
  • A matched cohort study showed that compared to those who only received monovalent vaccines, the bivalent vaccine had a 70.3% effectiveness rate in preventing hospitalizations due to COVID-19.
  • The bivalent booster not only sustained strong protection for over three months but also demonstrated effectiveness against medically attended SARS-CoV-2 infections (55.0%) and COVID-19 hospital deaths (82.7%).
View Article and Find Full Text PDF
Article Synopsis
  • A cohort study was conducted at Kaiser Permanente Southern California to assess the connection between mRNA COVID-19 vaccines and the occurrence of herpes zoster (HZ), which is a viral infection also known as shingles.
  • The study compared over 1 million vaccinated individuals who received either the mRNA-1273 or BNT162b2 vaccines to unvaccinated individuals, identifying HZ cases within 90 days post-vaccination using diagnosis codes and antiviral treatments.
  • Results indicated a small increased risk of developing HZ after the second dose, especially in individuals aged 50 and older who hadn’t received the zoster vaccine, highlighting a potential safety concern for this age group.
View Article and Find Full Text PDF
Article Synopsis
  • HepB-CpG (Heplisav-B) is a hepatitis B vaccine that requires only 2 doses, while HepB-alum (Engerix-B) requires 3 doses, prompting a study to assess the safety of these vaccines regarding new immune-mediated diseases, herpes zoster, and anaphylaxis in a real-world setting.
  • A cohort study followed 69,625 adults who received either vaccine between 2018 and 2019, using electronic health records to track the incidence of the specified outcomes for 13 months.
  • Results showed similar rates of immune-mediated diseases between both vaccines, except for rheumatoid arthritis, which was initially higher for HepB-CpG but adjusted to show no significant difference after
View Article and Find Full Text PDF
Article Synopsis
  • - The study analyzed the effectiveness of receiving a fourth dose of the mRNA-1273 vaccine compared to only three doses in people aged 50 and older, involving nearly 357,000 participants from Kaiser Permanente Southern California.
  • - Results showed that the fourth dose significantly improved protection against SARS-CoV-2 infection (25.9% more effective), COVID-19 hospitalization (67.3% more effective), and death from COVID-19 (72.5% more effective).
  • - However, the effectiveness of the fourth dose decreased over time, particularly 2-4 months after vaccination, indicating that while four doses offer better protection, the level of effectiveness can vary and diminish in various demographic groups.
View Article and Find Full Text PDF

Background: Data on the effectiveness of the 3-dose mRNA-1273 primary series are limited, particularly in comparison to 2 doses. Given suboptimal COVID-19 vaccine uptake among immunocompromised populations, it is important to monitor the effectiveness of fewer than the recommended doses in this population.

Methods: We conducted a matched cohort study at Kaiser Permanente Southern California to evaluate the relative vaccine effectiveness (rVE) of the 3-dose series vs 2 doses of mRNA-1273 in preventing SARS-CoV-2 infection and severe COVID-19 outcomes among immunocompromised individuals.

View Article and Find Full Text PDF

Background: Measles, mumps, and rubella vaccine (MMR) is routinely administered to children; however, adolescents and adults may receive MMR for various reasons. Safety studies in adolescents and adults are limited. We report on safety of MMR in this age group in the Vaccine Safety Datalink.

View Article and Find Full Text PDF
Article Synopsis
  • * The study, including over 123,000 individuals, finds that while three doses of the mRNA-1273 vaccine provide strong initial protection against infections, effectiveness diminishes quickly for newer subvariants like BA.2.12.1, BA.4, and BA.5 after the third dose.
  • * Hospitalization protection remains high with three doses but shows variability; four doses boost effectiveness but still drop significantly after a few months, indicating a need for evaluation of updated booster shots.
View Article and Find Full Text PDF