Unvaccinated Group Research Articles

Three-year Profile of COVID-19 Cases in Eastern Visayas, the Philippines (2020–2023)

This paper presents a three-year profile of laboratory-confirmed COVID-19 cases in Eastern Visayas, the Philippines, from 23 Mar 2020–31 Mar 2023 – with descriptive data on temporal trends, geographical variations, demographic factors, clinical characteristics, transmission patterns, and outcomes for vaccinated and unvaccinated cases. We analyzed data from the Regional Epidemiology and Surveillance Unit, Department of Health–Eastern Visayas Center for Health and Development to identify associations between COVID-19 severity and mortality and demographic and clinical factors. Moreover, we examined significant differences across gender cohorts and between vaccinated and unvaccinated individuals. During the three-year period, Eastern Visayas recorded 64,740 confirmed cases, with 98.93% recovery and 1.07% mortality. Most cases (61.72%) occurred in 2021 – with Tacloban, Ormoc, and Leyte having the highest attack rates per 100,000 population. Infections were asymptomatic (70.40%) or mild (21.83%), and 82.7% of deaths were linked to severe infections. Females accounted for 52.6% of the patients, with a lower mortality rate (44.5%) than males (55.5%). The 20–29 age group had the highest count (22.57%), whereas the 70–79 age group recorded the highest number of deaths (25.94%). The vast majority (93.6%) had no comorbidities. Comorbidities reported among deaths included kidney disease (11.3%), heart disease (7.6%), and hypertension (3.9%). Notably, no significant differences in recoveries and deaths were found between vaccinated and unvaccinated groups (p-value = 0.304). Logistic regression analysis showed that gender, age group, place of residence, comorbidity, and vaccination status were significantly associated with disease severity and mortality. Eastern Visayas demonstrated a relatively low COVID-19 caseload (1.59%) within the cumulative Philippine count. This is the most extensive COVID-19 case profile in the Philippines to date, hence providing essential data for pandemic preparedness, enhanced response strategies, and regional health crisis resilience.

A Critical Analysis of All-Cause Deaths during COVID-19 Vaccination in an Italian Province.

Immortal time bias (ITB) is common in cohort studies and distorts the association estimates between the treated and untreated. We used data from an Italian study on COVID-19 vaccine effectiveness, with a large cohort, long follow-up, and adjustment for confounding factors, affected by ITB, with the aim to verify the real impact of the vaccination campaign by comparing the risk of all-cause death between the vaccinated population and the unvaccinated population. We aligned all subjects on a single index date and considered the "all-cause deaths" outcome to compare the survival distributions of the unvaccinated group versus various vaccination statuses. The all-cause-death hazard ratios in univariate analysis for vaccinated people with 1, 2, and 3/4 doses versus unvaccinated people were 0.88, 1.23, and 1.21, respectively. The multivariate values were 2.40, 1.98, and 0.99. Possible explanations of this trend of the hazard ratios as vaccinations increase could be a harvesting effect; a calendar-time bias, accounting for seasonality and pandemic waves; a case-counting window bias; a healthy-vaccinee bias; or some combination of these factors. With 2 and even with 3/4 doses, the calculated Restricted Mean Survival Time and Restricted Mean Time Lost have shown a small but significant downside for the vaccinated populations.

Expectations Versus Fantasies and Vaccine Hesitancy: How Suffering From COVID-19 Versus Suffering From Vaccines Interact.

Previous research on COVID-19 vaccination highlights future thoughts associated with possible Coronavirus infection and vaccine side effects as key predictors of vaccine hesitancy. Yet, research has focused on independent contributions of such future thoughts, neglecting their interactive aspects. We examined whether thoughts about two possible COVID-related futures (suffering from COVID-19 and vaccine side effects) interactively predict vaccine hesitancy and vaccination behavior among unvaccinated and vaccinated people. Importantly, we compared two forms of future thinking: beliefs or expectations (likelihood judgments) versus fantasies (free thoughts and images describing future events). In Study 1, we conducted a longitudinal study with an unvaccinated group (N = 210). We assessed expectations versus fantasies about the two COVID-related futures as predictors. As outcome variables, we measured vaccine hesitancy, and 9 weeks later we assessed information seeking and vaccine uptake. Study 2 was a cross-sectional study comparing vaccine hesitancy of an unvaccinated group (N = 307) to that of a vaccinated group (N = 311). Study 1 found that more negative fantasies about COVID-19 impact and less negative fantasies about vaccine side effects interactively predicted lower vaccine hesitancy and more vaccine-related behaviors among unvaccinated people; no such interaction was observed between respective expectations. Study 2 replicated these results of Study 1. Additionally, for vaccinated people, low expectations of negative COVID-19 impact and high expectations of negative vaccine impact interactively predicted higher vaccine hesitancy, whereas no such interaction was observed for respective fantasies. Research on vaccine hesitancy should explore interactions between future thinking about disease and about vaccine side effects. Importantly, there is much to be gained by distinguishing expectations versus fantasies: vaccination interventions aiming to boost vaccine uptake among unvaccinated people should tap into their negative future fantasies regarding both disease and vaccine side effects.

Tailored vs. General COVID-19 prevention for adults with mental disabilities residing in group homes: a randomized controlled effectiveness-implementation trial

BackgroundPeople with serious mental illness (SMI) and people with intellectual disabilities/developmental disabilities (ID/DD) are at higher risk for COVID-19 and more severe outcomes. We compare a tailored versus general best practice COVID-19 prevention program in group homes (GHs) for people with SMI or ID/DD in Massachusetts (MA).MethodsA hybrid effectiveness-implementation cluster randomized control trial compared a four-component implementation strategy (Tailored Best Practices: TBP) to dissemination of standard prevention guidelines (General Best-Practices: GBP) in GHs across six MA behavioral health agencies. GBP consisted of standard best practices for preventing COVID-19. TBP included GBP plus four components including: (1) trusted-messenger peer testimonials on benefits of vaccination; (2) motivational interviewing; (3) interactive education on preventive practices; and (4) fidelity feedback dashboards for GHs. Primary implementation outcomes were full COVID-19 vaccination rates (baseline: 1/1/2021–3/31/2021) and fidelity scores (baseline: 5/1/21–7/30/21), at 3-month intervals to 15-month follow-up until October 2022. The primary effectiveness outcome was COVID-19 infection (baseline: 1/1/2021–3/31/2021), measured every 3 months to 15-month follow-up. Cumulative incidence of vaccinations were estimated using Kaplan-Meier curves. Cox frailty models evaluate differences in vaccination uptake and secondary outcomes. Linear mixed models (LMMs) and Poisson generalized linear mixed models (GLMMs) were used to evaluate differences in fidelity scores and incidence of COVID-19 infections.ResultsGHs (n=415) were randomized to TBP (n=208) and GBP (n=207) including 3,836 residents (1,041 ID/DD; 2,795 SMI) and 5,538 staff. No differences were found in fidelity scores or COVID-19 incidence rates between TBP and GBP, however TBP had greater acceptability, appropriateness, and feasibility. No overall differences in vaccination rates were found between TBP and GBP. However, among unvaccinated group home residents with mental disabilities, non-White residents achieved full vaccination status at double the rate for TBP (28.6%) compared to GBP (14.4%) at 15 months. Additionally, the impact of TBP on vaccine uptake was over two-times greater for non-White residents compared to non-Hispanic White residents (ratio of HR for TBP between non-White and non-Hispanic White: 2.28, p = 0.03).ConclusionTailored COVID-19 prevention strategies are beneficial as a feasible and acceptable implementation strategy with the potential to reduce disparities in vaccine acceptance among the subgroup of non-White individuals with mental disabilities.Trial registrationClinicalTrials.gov, NCT04726371, 27/01/2021. https://clinicaltrials.gov/study/NCT04726371.

Investigating the predictors of COVID-19 vaccine decision-making among parents of children aged 5–11 in the UK

BackgroundThe global effort to combat the COVID-19 pandemic highlights the pivotal role of vaccination in public health, particularly considering emerging severe acute respiratory syndrome-coronavirus-2 variants. While priority has been given to immunising vulnerable populations, children remain a significant unvaccinated group, prompting NHS England to include them in their new vaccination strategy. The role parents play in child healthcare decisions, specifically regarding COVID-19 vaccination, is crucial, and the Health Belief Model (HBM) provides a framework for understanding parental vaccination behaviour. MethodsTo investigate the predictors influencing parental decision-making for COVID-19 vaccination in children aged 5–11, an online cross-sectional survey was conducted amongst parents (n = 206) living in the UK aged > 18, with one or more children aged 5–11. The present study measured HBM constructs, demographic factors, vaccine hesitancy and vaccine decision-making self-efficacy. Binomial logistic regression was used to analyse the responses of 206 participants using the child vaccination status (vaccinated vs. unvaccinated) as the outcome variable. FindingsThe regression model significantly predicted child vaccination status, identifying perceived barriers, cues to action and parent age as significant predictors. Higher cues to action and older parent age increased the likelihood of child vaccination, while greater perceived barriers decreased it. The model achieved 80.8 % overall accuracy by correctly identifying 87.6 % of vaccinated cases and 69.4 % of unvaccinated cases, demonstrating high accuracy in predicting parental vaccination decisions. ConclusionThe present study contributes to our understanding of the factors shaping parental decision-making regarding COVID-19 child vaccination, highlighting the impact of perceived barriers, cues to action and parent age. Future public health campaigns should address the specific barriers faced by parents, emphasise external cues to action and tailor messaging to acknowledge age-related differences in parental vaccine decision-making. By addressing the aforementioned factors influencing parental behaviour regarding child vaccination, future interventions can increase the number of children vaccinated against COVID-19, preventing transmission, protecting from severe illness and contributing to the NHS vaccination strategy.

Duration of Protection and Humoral Immune Response in Nile Tilapia (Oreochromis niloticus L.) Vaccinated against Streptococcus agalactiae.

Streptococcosis caused by Streptococcus agalactiae (S. agalactiae) is a major bacterial disease affecting the production of Nile tilapia (Oreochromis niloticus L.), causing significant economic losses due to mortality in the growing phase. Vaccination is the most effective method for preventing streptococcosis on Nile tilapia farms. In Brazil, the major tilapia-producing regions have long production cycles (6-10 months) and harvest tilapias weighing over 900 g for fillet production. Thus, data on the duration of the humoral immune response and protection in farmed tilapia have not been reported or are poorly described. Furthermore, the efficiency of serological testing for the long-term monitoring of immune responses induced by vaccination against S. agalactiae has never been addressed. This study evaluated the duration of protection and humoral immune response induced in Nile tilapia vaccinated against S. agalactiae until 300 days post-vaccination (dpv). The immunization trial was composed of two groups: vaccinated (Vac), vaccinated intraperitoneally with a commercial vaccine, and unvaccinated (NonVac) group, injected fish with sterile saline solution. At 15, 30, 150, 180, 210, and 300 dpv, blood sampling was conducted to detect anti-S. agalactiae IgM antibodies using indirect Enzyme-Linked Immunosorbent Assay (ELISA), and the fish were challenged with pathogenic S. agalactiae to determine the duration of vaccine protection through relative percentage survival (RPS). Spearman's rank correlation was performed between the ELISA optical density (OD) of vaccinated tilapia and the duration of vaccine protection (RPS). The mean cumulative mortality in NonVac and Vac groups ranged from 65 to 90% and less than 35%, respectively. The average RPS was 71, 93, 94, 70, 86, and 67% at 15, 30, 150, 180, 210, and 300 dpv, respectively. RPS revealed that the vaccine provided protection from 15 to 300 dpv. The specific anti-S. agalactiae IgM antibody levels were significantly higher in the Vac group than that non-Vac group up to 180 dpv. The vaccinated fish exhibited significant protection for up to 10 months after vaccination. There was a positive correlation between the antibody response and RPS. This study revealed that a single dose of commercial vaccine administered to Nile tilapia can confer long-term protection against S. agalactiae and that indirect ELISA can monitor the duration of the humoral immune response for up to six months following vaccination. Finally, vaccine protection over six months can be associated with other components of the fish immune system beyond the humoral immune response by IgM antibodies.

Effectiveness of BNT162b2 Against Infection, Symptomatic Infection, and Hospitalization Among Older Adults Aged ≥65 Years During the Delta Variant Predominance in Japan: The VENUS Study.

We evaluated the effectiveness of the BNT162b2 vaccine against infection, symptomatic infection, and hospitalization in older people during the Delta-predominant period (July 1 to September 30, 2021). We performed a population-based cohort study in an older adult population aged ≥65 years using data from the Vaccine Effectiveness, Networking, and Universal Safety Study conducted from January 1, 2019, to September 30, 2021, in Japan. We matched BNT162b2-vaccinated and -unvaccinated individuals in a 1:1 ratio on the date of vaccination of the vaccinated individual. We evaluated the effectiveness of the vaccine against infection, symptomatic infection, and coronavirus disease (COVID-19)-related hospitalization by comparing the vaccinated and unvaccinated groups. We estimated the risk ratio and risk difference using the Kaplan-Meier method with inverse probability weighting. The vaccine effectiveness was calculated as (1 - risk ratio) × 100%. The study included 203,574 matched pairs aged ≥65 years. At 7 days after the second dose, the vaccine effectiveness of BNT162b2 against infection, symptomatic infection, and hospitalization was 78.1% (95% confidence interval [CI], 65.2-87.8%), 79.1% (95% CI, 64.6-88.9%), and 93.5% (95% CI, 83.7-100%), respectively. BNT162b2 was highly effective against infection, symptomatic infection, and hospitalization in Japan's older adult population aged ≥65 years during the Delta-predominant period.

MRNA vaccines protect from the lung microvasculature injury and the capillary blood volume loss occurring in SARS-CoV-2 paucisymptomatic infections.

The reduction of lung capillary blood volume (Vc) had been identified as the microvascular injury mostly underlying the respiratory Long-COVID syndrome following post-COVID-19 pneumonia. The same kind of injury have been recently also found in several individuals after milder paucisymptomatic SARS-CoV-2 infections. Though current guidelines strongly recommend vac-cination, studies aimed to investigate the in vivo protection of anti-SARS-CoV-2 vaccines on lung microvascular targets still are missing to our best knowledge. to assess the protection of mRNA vaccines from the reduction of lung capillary blood volume (Vc) caused by pauci-symptomatic SARS.CoV-2 infections in vaccinated compared to unvaccinated individuals. Non-smoking individuals with recent paucisymptomatic SARS-CoV-2 infection were divided into vaccinated and unvaccinated groups. Lung function parameters, including single-breath diffusing capacity and microvascular blood volume, were compared between groups. fifty vaccinated and twenty-five unvaccinated well-matched individuals were studied. Differently than usual lung function parameters, only the single-breath simultaneous assessment of sDLCO, sDLNO/sDLCO ratio and Vc allowed to identify the occurrence of the lung microvascular injury with high sensitivity and specificity (p<0.001). mRNA vaccines proved to exert a high protection from the loss of lung capillary blood volume (Vc) induced by SARS.CoV-2 paucisymptomatic infections (p<0.001). The availability of this non-invasive investigational model should be regarded as a very helpful tool for assessing and comparing in vivo the protective effect of mRNA vaccines on the human microvascular structures of the deep lung.

Impact of Circulating Anti-Spike Protein Antibody Levels on Multi-Organ Long COVID Symptoms.

Patients with long COVID syndrome present with various symptoms affecting multiple organs. Vaccination before or after SARS-CoV-2 infection appears to reduce the incidence of long COVID or at least limit symptom deterioration. However, the impact of vaccination on the severity and extent of multi-organ long COVID symptoms and the relationship between the circulating anti-spike protein antibody levels and the severity and extent of multi-organ symptoms are unclear. This prospective cohort study included 198 patients with previous PCR-verified SARS-CoV-2 infection who met the criteria for long COVID syndrome. Patients were divided into vaccinated (n = 138, 69.7%) or unvaccinated (n = 60, 30.3%) groups. Anti-spike protein antibody levels were determined at initial clinical presentation and compared between the groups. Long COVID symptoms were quantified on the basis of the number of affected organs: Class I (mild) with symptoms in three organs, Class II (moderate) with symptoms in four to five organs, and Class III (severe) with symptoms in six or more organ systems. Associations between time to infection and vaccination with anti-spike protein antibody levels were assessed. The anti-spike protein antibody levels were 1925 ± 938 vs. 481 ± 768 BAU/mL (p < 0.001) in the vaccinated vs. unvaccinated patients. The circulating anti-spike antibody cutoff of 665.5 BAU/mL allowed us to differentiate the vaccinated from the unvaccinated patients. Vaccinated patients had fewer class II and class III multi-organ symptoms (Class II 39.9% vs. 45.0%; Class III 10.1% vs. 23.3%, p-value 0.014). Anti-spike antibody level correlated negatively with multi-organ symptom classes (p = 0.016; 95% CI -1.229 to -0.126). Anti-spike antibody levels in unvaccinated patients declined markedly with time, in contrast to the persistence of high anti-spike antibody levels in the vaccinated patients. Multi-organ symptoms were lower in vaccinated long-COVID patients, especially in those with higher anti-spike antibody levels (≥665.5 BAU/mL). Classifying the symptoms on the basis of the number of affected organs enables a more objective symptom quantification.

The impact of COVID-19 mRNA vaccines on immune-related adverse events in patients with cancer receiving immune checkpoint inhibitors.

2648 Background: Cancer patients are a vulnerable population to COVID-19. COVID-19 mRNA vaccines have shown to decrease hospitalization and death risk from COVID-19 in cancer patients. Concurrent COVID-19 vaccination and immune checkpoint inhibitors (ICIs) use may impact immune-related adverse events (irAEs) synergistically. Limited data exist on how COVID-19 mRNA vaccines affect irAEs in ICI-treated cancer patients, especially those with breakthrough infections. Methods: We retrospectively analyzed adult patients with malignant solid tumors receiving ICIs at a single cancer institute (January 2020 to July 2021). Fully vaccinated status is defined as two consecutive doses of mRNA vaccines (BNT162b2 and mRNA-1273). Patients who were partially vaccinated, fully vaccinated post COVID-19 infection, vaccinated with non-mRNA COVID-19 vaccines, or last visit within 30 days post vaccination were excluded. All COVID-19 infections were confirmed by PCR. In the vaccinated group, only post-vaccination irAEs were considered as events. Results: 443 patients were included in our study, with 251 (56.7%) vaccinated and 192 (43.3%) unvaccinated. The baseline characteristics were similar between the two groups, except for age (vaccinated median 68 years, unvaccinated median 62 years, p=0.004). With a median follow-up of 12 months, incidences of all-grade irAEs (19.1% vs. 20.3%, p=0.72) and severe irAEs (5.6% vs. 4.2%, p=0.66) were comparable between vaccinated and unvaccinated groups. 34 breakthrough COVID-19 infections occurred. In the vaccinated group, a non-significant trend of higher all-grade irAEs incidence was noted in the COVID-19 infected subgroup compared to uninfected subgroup (29.4% vs. 17.5%, p = 0.11). Univariate analysis linked COVID-19 vaccination (OR 1.54, 95% CI 1.01-2.35, p=0.04) and ipilimumab + nivolumab use (OR 5.57, 95% CI 1.79-17.35, p=0.003) to a higher risk of all-grade irAEs in the entire cohort. After multivariate adjustment, ipilimumab + nivolumab use remained the only variable associated with all-grade irAEs (OR 4.95, 95% CI 1.57-15.64, p=0.006). Conclusions: Our study suggests that COVID-19 mRNA vaccines do not increase irAE risk in cancer patients on ICIs. Fully vaccinated patients with breakthrough COVID-19 infections may safely continue ICI treatment without an increased irAE risk. [Table: see text]

A potential association between COVID-19 vaccination and development of alzheimer's disease.

The challenges of the COVID-19 pandemic extend to concerns about vaccine side effects, particularly potential links to neurodegenerative diseases such as Alzheimer's disease (AD). This study investigates the association between COVID-19 vaccination and the onset of AD and its prodromal state, mild cognitive impairment (MCI). A nationwide, retrospective cohort study leveraging data from the Korean National Health Insurance Service was conducted. The study, conducted in Seoul, South Korea, analyzed data from a random 50% sample of city residents aged 65 and above, totaling 558,017 individuals. Participants were divided into vaccinated and unvaccinated groups, with vaccinations including mRNA and cDNA vaccines. The study focused on AD and MCI incidences post-vaccination, identified via ICD-10 codes, using multivariable logistic and Cox regression analyses. Patients with vascular dementia or Parkinson's disease served as controls. Findings showed an increased incidence of MCI and AD in vaccinated individuals, particularly those receiving mRNA vaccines, within three months post-vaccination. The mRNA vaccine group exhibited a significantly higher incidence of AD (Odds Ratio [OR]: 1.225; 95% Confidence Interval [CI]: 1.025-1.464; p = 0.026) and MCI (OR: 2.377; CI: 1.845-3.064; p < 0.001) compared to the unvaccinated group. No significant relationship was found with vascular dementia or Parkinson's disease. Preliminary evidence suggests a potential link between COVID-19 vaccination, particularly mRNA vaccines, and increased incidences of AD and MCI. This underscores the need for further research to elucidate the relationship between vaccine-induced immune responses and neurodegenerative processes, advocating for continuous monitoring and investigation into the vaccines' long-term neurological impacts.

Assessment of COVID-19 vaccine effectiveness in a nation with a low vaccination coverage: insights from real-world data and propensity score matched analyses

We conducted a comprehensive evaluation of COVID-19 vaccine effectiveness in reducing mortality rates in a country with a low vaccination coverage. A retrospective cohort study analysed data from 1,048,574 adult (≥ 18) patients spanning from March 2020 to April 2022, using data from the national digital medical record repository. Univariate analysis and logistic regression calculated odds ratios and their significance. Propensity score matching was utilised to strengthen the statistical results. Among the 1,048,574 patients diagnosed with COVID-19, 73% (n = 780,718) were unvaccinated, and 27% (n = 267,856) were reported as fully vaccinated. Unadjusted statistical analyses revealed a significant reduction in mortality rates among the vaccinated cohort (1,608 deaths; 0.6%) compared to the unvaccinated group (40,985 deaths; 5.2%) [OR 0.1090 (95%CI 0.1037 to 0.1146), p < 0.0001]. This outcome was consistent across all subgroups, including patient sex, age group, in-hospital setting, vaccine type, SARS-CoV-2 variant, and high-risk patient groups (i.e. with a solid malignancy, cardiovascular disease, chronic pulmonary disease or diabetes mellitus). Logistic regression revealed that the highest fatal risk was in non-vaccinated males aged >63. Propensity score matching substantiated the observed reduction in mortality rates across the entire vaccinated cohort and within all patient subgroups. Individuals infected with SARS-CoV-2 face an elevated risk of premature mortality. Vaccination, especially when utilising mRNA-based platforms, significantly mitigates this risk, particularly among high-risk populations.

Impact of the COVID-19 vaccinations on economic outcomes and mental health services in the U.S

The development of vaccines has long been viewed as a critical public health tool to raise immunity against the COVID-19 virus and to reopen economic activities globally. Against this background, this study examines the impact of COVID-19 vaccinations on economic outcomes and mental health services in the U.S. We employed the Household Pulse Survey covering 549, 950 and 57, 892 vaccinated and unvaccinated individuals, respectively. For the causal analysis, we control the differences between the vaccinated and unvaccinated groups using propensity score matching (PSM) and augmented inverse probability weighting (AIPW) methods. Economic outcomes include whether individuals work on-site, telework or work from home, in-store shopping, job loss, or food sufficient. We also consider whether individuals experience mental health distress and receive mental health services as a potential outcome. The empirical results show that the probability of working on-site, in-store shopping, food sufficiency, and using mental health services are significantly higher among the recipients of the COVID-19 vaccines than non-recipients. We also find that the likelihood of teleworking and job loss decreased significantly among the recipients of the COVID-19 vaccine compared to non-recipients. The magnitude of the estimated impact across race and ethnic groups is mixed, which shows that vaccination effects are heterogeneous across the races/ethnic groups in the sample.

Varicella-Zoster Virus-Induced Neurologic Disease After COVID-19 Vaccination: A Multicenter Observational Cohort Study.

Early reports described an increased risk of herpes zoster following receipt of mRNA-based COVID-19 vaccines. The objective was to assess whether COVID-19 vaccine is associated with varicella-zoster virus-induced neurologic disease (VZV-ND). This multicenter retrospective case-control study with a test-negative design was conducted at 12 hospitals in Israel. We included all patients admitted with VZV-ND between January 2020 and December 2021 and matched controls with a negative polymerase chain reaction result for VZV in cerebrospinal fluid. We identified 188 patients meeting the case definition of VZV-ND who were admitted during the study period. Cases were matched with 376 controls. There was no significant variation in the incidence of VZV-ND between 1 year preceding and 1 year following the deployment of BNT162b2 in Israel. Analysis of persons who had received at least 1 dose of COVID-19 vaccine (n = 259) showed similar proportions of VZV-ND and non-VZV-ND in 4 intervals (30, 42, 50, 60 days) following the last vaccine dose. The median time from the last vaccine dose to hospitalization with a neurologic syndrome was 53 days (IQR, 25-128) and 82 days (IQR, 36-132) for VZV-ND and non-VZV-ND, respectively, not reaching statistical significance (P = .056). The rate of VZV-ND in vaccinated patients was no different from the rate in the unvaccinated group (30.9% vs 35.4%, P = .2). We did not find an association between COVID-19 vaccine and VZV-ND. Since COVID-19 vaccine is now recommended yearly, every fall and winter, establishing the safety of the vaccine is of great importance.

Importance of Examining Incidentality in Vaccine Safety Assessment

The author believes that the principles of statistical methods for vaccine safety can be divided into three categories: comparison of adverse event incidence rates between vaccinated and unvaccinated groups, analysis of incidentality in the vaccinated group, and a combination of both. The first category includes the cohort study; the second, the self-controlled risk interval design (SCRI); and the third, the self-controlled case series method. A single p-value alone should not determine a scientific conclusion, and analysis should be performed using multiple statistical methods with different principles. The author believes that using both the cohort study and the SCRI for analysis is the best method to assess vaccine safety. When the cohort study may not detect a significant difference owing to a low incidence rate of an adverse event in the vaccinated group or a high one in the unvaccinated group, the SCRI may detect it. Because vaccines must have a higher level of safety than the pharmaceuticals used for treatment, vaccine safety is advisable to be assessed using methods that can detect a significant difference even for any value of the incidence rate of an adverse event. The author believes that the analyses of COVID-19 vaccine safety have areas for improvement because the proportion of papers that used the cohort study and the SCRI was negligible.

The association of COVID-19 vaccination and menstrual health: A period-tracking app-based cohort study

BackgroundIn initial COVID-19 clinical trials, menstrual health was not formally monitored, yet anecdotal reports of menstruation changes surfaced on social media. This study aims to assess the association between COVID-19 vaccines and menstruation using Clue, a period-tracking application. Study designA survey assessing demographics, menstrual health, stress levels, and COVID-19 vaccination was sent to Clue users between 12/7/2021 and 2/9/2022. Inclusion criteria were (1) 18 years or older (2) currently menstruating (3) not pregnant or breastfeeding since 1/2020. Menstrual data was collected for each participant. Users with cycle lengths more than 90 days were excluded. Cycle lengths were calculated for the 6-month average pre-vaccination (PRIOR), the cycle during which vaccination was administered (DURING), the cycle following DURING (AFTER1), and the cycle following AFTER1 (AFTER2). For periods, individuals were stratified based on whether vaccination was received during their menstrual period (DURING). Period lengths were additionally calculated for the 6-month average pre-vaccination (PRIOR), the first period following vaccination (AFTER1), and the period following AFTER1 (AFTER2). For unvaccinated participants, an index date (4/1/2022) was used to similarly designate menstrual cycles and periods. For each participant, cycle length changes for DURING, AFTER1, and AFTER2 compared to PRIOR were determined. Student’s t-test compared the mean of these changes between vaccinated and unvaccinated groups. ResultsOf 7,559 participants, 6,897 (91 %) were vaccinated. Compared to PRIOR, individuals vaccinated during their menstrual period demonstrated a statistically significant increase in the DURING period length, but not AFTER1 (p = 0.463) and AFTER2 (p = 0.692). No statistically significant changes were observed in period lengths of those vaccinated in between periods or in cycle lengths overall. ConclusionA small but statistically significant change in period length was observed only in individuals vaccinated for COVID-19 during their menstrual period. Providers can better counsel menstruating individuals to reduce vaccine misinformation.

Effect of the HPV vaccination programme on incidence of cervical cancer and grade 3 cervical intraepithelial neoplasia by socioeconomic deprivation in England: population based observational study

ObjectivesTo replicate previous analyses on the effectiveness of the English human papillomavirus (HPV) vaccination programme on incidence of cervical cancer and grade 3 cervical intraepithelial neoplasia (CIN3) using 12 additional...

SARS-CoV-2 vaccine effectiveness and clinical outcomes in hemodialysis patients: the NHIS-COVID-19 cohort study in South Korea.

Patients undergoing hemodialysis (HD) have a high risk of novel coronavirus disease 2019 (COVID-19) and poor clinical outcomes. This study aimed to investigate severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) vaccine effectiveness against infection and deaths in the South Korean population undergoing HD. We conducted a retrospective cohort study to compare the incidence of COVID-19 and post-diagnosis mortality between patients who were either never vaccinated or fully or partially vaccinated. The Korean nationwide COVID-19 registry and the Korean National Health Insurance Service databases were used. Adult patients without a history of COVID-19 were included between October 8, 2020, and December 31, 2021. The study outcomes were COVID-19 diagnosis, severe clinical COVID-19-related events, and post-diagnosis death. Eighty-five thousand eighteen patients undergoing HD were included, of whom 69,601 were fully vaccinated, 2,213 were partially vaccinated and 13,204 were unvaccinated. Compared with the unvaccinated group, the risk of being diagnosed with COVID-19 in patients who were fully vaccinated decreased during the study period (adjusted odds ratio [aOR] = 0.147; 95% confidence interval [CI] = 0.135-0.159). There were 1,140 (1.3%) patients diagnosed with COVID-19. After diagnosis, fully vaccinated patients were significantly less likely to die than unvaccinated patients (aOR = 0.940; 95% CI = 0.901-0.980) and to experience severe clinical events (aOR = 0.952; 95% CI = 0.916-0.988). Full vaccination against COVID-19 was associated with a reduced risk of both infection and severe clinical outcomes in the South Korean population undergoing HD. These findings support the use of vaccination against SARS-CoV-2 among patients undergoing HD.

Herpesviral Keratitis Following COVID-19 Vaccination: Analysis of NHIS Database in Korea.

The purpose of this study was to determine the risk of herpesviral keratitis associated with 4 coronavirus disease 2019 (COVID-19) vaccines approved in South Korea, using large-scale data from the National Health Insurance Service. The study included 8,528,254 individuals, with cohorts categorized based on COVID-19 vaccination status. Two investigations were conducted: The first aimed to assess the risk of new-onset herpesviral keratitis while the second study focused on the risk of relapse in individuals with a preexisting diagnosis. Propensity score matching was used for cohort balancing, and various covariates, including vaccine types and comorbidities, were considered. Statistical analyses, including Cox proportional hazard regression, were used to calculate adjusted hazard ratio (aHR) and assess the risk of herpesviral keratitis. Individuals receiving COVID-19 vaccination exhibited a higher risk of new-onset herpesviral keratitis compared with the unvaccinated control group (aHR 1.43, 95% confidence interval, 1.19-1.73). Both mRNA and non-mRNA vaccines demonstrated an increased risk. Individuals with preexisting herpetic keratitis who received COVID-19 vaccination showed a higher risk of relapse herpesviral keratitis compared with the unvaccinated control group (aHR 1.98, 95% CI, 1.29-3.03). Sensitivity analyses supported the robustness of the results. This analysis of a large national health insurance database suggests an increased risk of both new-onset and relapse of herpesviral keratitis associated with COVID-19 vaccination in South Korea. While COVID-19 vaccination is crucial for pandemic control, health care providers should be aware of potential herpesvirus reactivation and consider appropriate prophylaxis and treatment for at-risk individuals.

Impact of Vaccination Status on Outcome of Patients With COVID-19 and Acute Ischemic Stroke Undergoing Mechanical Thrombectomy.

Data on impact of COVID-19 vaccination and outcomes of patients with COVID-19 and acute ischemic stroke undergoing mechanical thrombectomy are scarce. Addressing this subject, we report our multicenter experience. This was a retrospective analysis of patients with COVID-19 and known vaccination status treated with mechanical thrombectomy for acute ischemic stroke at 20 tertiary care centers between January 2020 and January 2023. Baseline demographics, angiographic outcome, and clinical outcome evaluated by the modified Rankin Scale score at discharge were noted. A multivariate analysis was conducted to test whether these variables were associated with an unfavorable outcome, defined as modified Rankin Scale score >3. A total of 137 patients with acute ischemic stroke (48 vaccinated and 89 unvaccinated) with acute or subsided COVID-19 infection who underwent mechanical thrombectomy attributable to vessel occlusion were included in the study. Angiographic outcomes between vaccinated and unvaccinated patients were similar (modified Thrombolysis in Cerebral Infarction ≥2b: 85.4% in vaccinated patients versus 86.5% in unvaccinated patients; P=0.859). The rate of functional independence (modified Rankin Scale score, ≤2) was 23.3% in the vaccinated group and 20.9% in the unvaccinated group (P=0.763). The mortality rate was 30% in both groups. In the multivariable analysis, vaccination status was not a significant predictor for an unfavorable outcome (P=0.957). However, acute COVID-19 infection remained significant (odds ratio, 1.197 [95% CI, 1.007-1.417]; P=0.041). Our study demonstrated no impact of COVID-19 vaccination on angiographic or clinical outcome of COVID-19-positive patients with acute ischemic stroke undergoing mechanical thrombectomy, whereas worsening attributable to COVID-19 was confirmed.