Measuring vaccine protection when the population is mostly vaccinated

OBJECTIVES

This study aims to address limitations in assessing vaccine protection using the classical vaccine effectiveness (VE) measure, especially in contexts where a significant portion of the population is already vaccinated or infected.

STUDY DESIGN AND SETTING

We propose using the adjusted number of cases (ANC) as a building block for deriving vaccine effectiveness measures. This approach accounts for biases arising from small and unrepresentative unvaccinated reference groups with incomplete data. We demonstrate the use of these measures for assessing the protection conferred by a booster dose against severe COVID-19 using data from Israel.

RESULTS

The use of ANC and the derived measures reveals a more comprehensive understanding of the complex immunity landscape compared to traditional VE measures. This approach enables meaningful comparisons between different vaccination categories and provides insights to inform policy decisions.

CONCLUSION

In situations with widespread vaccination and prior infections, traditional VE measures can be limited in their informative value. Using the ANC offers a more robust and insightful assessment of vaccine effectiveness. A demonstration of the evaluation of booster dose protection against severe COVID-19 in Israel underscores the importance of adopting complementary measures to guide public health strategies.

Issues in Implementing Regression Calibration Analyses

Regression calibration is a popular approach for correcting biases in estimated regression parameters when exposure variables are measured with error. This approach involves building a calibration equation to estimate the value of the unknown true exposure given the error-prone measurement and other covariates. The estimated, or calibrated, exposure is then substituted for the unknown true exposure in the health outcome regression model. When used properly, regression calibration can greatly reduce the bias induced by exposure measurement error. Here, we first provide an overview of the statistical framework for regression calibration, specifically discussing how a special type of error, called Berkson error, arises in the estimated exposure. We then present practical issues to consider when applying regression calibration, including: 1) how to develop the calibration equation and which covariates to include; 2) valid ways to calculate standard errors of estimated regression coefficients; and 3) problems arising if one of the covariates in the calibration model is a mediator of the relationship between the exposure and outcome. Throughout, we provide illustrative examples using data from the Hispanic Community Health Study/Study of Latinos (United States, 2008-2011) and simulations. We conclude with recommendations for how to perform regression calibration.

Factors Associated With Protection From SARS-CoV-2 Omicron Variant Infection and Disease Among Vaccinated Health Care Workers in Israel

Importance

A correlation between antibody levels and risk of infection has been demonstrated for the wild-type, Alpha, and Delta SARS-COV-2 variants. High rates of breakthrough infections by the Omicron variant emphasized the need to investigate whether the humoral response elicited by mRNA vaccines is also associated with reduced risk of Omicron infection and disease.

Objective

To investigate whether the high antibody levels in individuals who have received at least 3 doses of an mRNA vaccine are associated with reduced risk of Omicron infection and disease.

Design, Setting, and Participants

This prospective cohort study used serial real time-polymerase chain reaction (RT-PCR) and serological test data from January and May 2022 to assess the association of preinfection immunoglobin G (IgG) and neutralizing antibody titers with incidence of Omicron variant infection, incidence of symptomatic disease, and infectivity. Participants included health care workers who had received 3 or 4 doses of an mRNA COVID-19 vaccine. Data were analyzed from May to August 2022.

Exposures

Levels of SARS-CoV-2 anti-receptor binding domain IgG and neutralizing antibodies.

Main Outcomes and Measures

The main outcomes were incidence of Omicron infection, incidence of symptomatic disease, and infectivity. Outcomes were measured using SARS-COV-2 PCR and antigen testing and daily online surveys regarding symptomatic disease.

Results

This study included 3 cohorts for 3 different analyses: 2310 participants were included in the protection from infection analysis (4689 exposure events; median [IQR] age, 50 [40-60] years; 3590 [76.6%] among female health care workers), 667 participants (median [IQR] age, 46.28 (37.44,54.8); 516 [77.4%] female) in the symptomatic disease analysis, and 532 participants (median [IQR] age, 48 [39-56] years; 403 [75.8%] female) in the infectivity analysis. Lower odds of infection were observed for each 10-fold increase in preinfection IgG (odds ratio [OR], 0.71; 95% CI, 0.56-0.90) and for each 2-fold increase in neutralizing antibody titers (OR, 0.89; 95% CI, 0.83-0.95). The odds of substantial symptomatic disease were reduced for each 10-fold increase in IgG levels (OR, 0.48; 95% CI, 0.29-0.78) and for each 2-fold increase in neutralizing antibodies levels (OR, 0.86; 95% CI, 0.76-0.96). Infectivity, assessed by mean cycle threshold value, was not significantly decreased with increasing IgG or neutralizing antibodies titers.

Conclusions and Relevance

In this cohort study of vaccinated health care workers, IgG and neutralizing antibody titer levels were associated with protection against infection with the Omicron variant and against symptomatic disease.

Protection against Omicron BA.1/BA.2 severe disease 0-7 months after BNT162b2 booster

Following evidence of waning immunity against both infection and severe disease after 2 doses of the BNT162b2 vaccine, Israel began administering a 3rd BNT162b2 dose (booster) in July 2021. Recent studies showed that the 3rd dose provides a much lower protection against infection with the Omicron variant compared to the Delta variant and that this protection wanes quickly. However, there is little evidence regarding the protection of the 3rd dose against Omicron (BA.1/BA.2) severe disease. In this study, we estimate the preservation of immunity from severe disease up to 7 months after receiving the booster dose. We calculate rates of severe SARS-CoV-2 disease between groups of individuals aged 60 and above, comparing those who received two doses at least 4 months previously to those who received the 3rd dose (stratified by the time from vaccination), and to those who received a 4th dose. The analysis shows that protection conferred by the 3rd dose against Omicron severe disease did not wane over a 7-month period. Moreover, a 4th dose further improved protection, with a severe disease rate approximately 3-fold lower than in the 3-dose cohorts.

Sucrose and Fructose in Spot Urine as a Biomarker of Total Sugars Intake – Findings From a Controlled Feeding Study

Objectives

To investigate the utility of sucrose and fructose measured in spot urine (uSF) as a measure of 24-h urinary sucrose and fructose (24uSF) and a biomarker of total sugars (TS) intake.

Methods

A hundred participants, 18–70 years of age, recruited from the Phoenix Metropolitan Area completed a 15-d controlled feeding study, which simulated their usual dietary behavior. Participants collected eight nonconsecutive 24-h urines; for two of the urine collections, each spot urine void was collected in a separate container. In the analysis, we considered four voids out of all voids collected for the day [AM void – 1^st void after a meal or between 8:30 am to 12:30 pm; PM void - 1^st void after a meal and between 12:31 pm to 5:30 pm; EVE void - 1^st void after a meal and between 5:31 pm to 12:00 am; and Next-day (ND) void - 1^st next day morning void and between 4:00 am to 12:00 pm]. We investigated the performance of uSF measured in one void, and uSF combined from two and three voids as a measure of 1) 24uSF and 2) TS intake.

Results

Among the four selected voids, averaged over two collection days, uSF measured in the EVE void correlated best with 24uSF [partial r (adjusted for urinary creatinine) = 0.69]. For uSF biomarker combined from two voids, PM/EVE void produced the strongest correlation with 24uSF (r = 0.75). The correlation only marginally improved, when adding a 3^rd void (PM/EVE/ND: r = 0.78). Based on these findings, we developed prediction equations for log(24uSF) based on log(uSF) measured in EVE, PM/EVE or PM/EVE/ND voids, adjusted for gender, log(age), BMI and log(creatinine). The R² from the linear mixed model relating predicted 24uSF based on EVE, PM/EVE or PM/EVE/ND voids with observed TS, age and gender was 0.30, 0.46 and 0.48, respectively. Biomarker-estimated TS intake based on log(24uSF) predicted from PM/EVE voids had moderate model-based estimates of correlation with ‘usual’ TS intake (for uSF measured in PM/EVE voids from 1 day, r = 0.34; from 2 days, r = 0.45; and from 4 days, r = 0.52).

Conclusions

Our findings suggest that uSF measured in PM/EVE voids performs well as a measure of 24uSF, and may be used to generate biomarker-based TS intake estimate when collecting of 24-urine is not feasible. Collecting PM and EVE voids over at least 2 nonconsecutive days rather than one day will produce less biased results.

Funding Sources

NIH - National Cancer Institute.

Added Sugars Intake Explained by Amino Acid Carbon Isotope Ratio Profiles in a Controlled Feeding Study of U.S. Adults

Objectives

To evaluate an amino acid carbon stable isotope ratio (CIRAA) biomarker of added sugars (AS) intake in a controlled feeding study of men and women across age and BMI groups.

Methods

We conducted a 15-d feeding study in Phoenix, AZ, of men and women (N = 100, aged 18–70 y, BMI 17.9–35.0) who were recruited across sex, age, and BMI groups. Participants were provided personalized diets that resembled their habitual intakes, based on 2 consecutive 7-d food records. We measured CIRAAs in serum samples (N = 99) collected at the end of the feeding period and determined correlations with dietary intakes. We used forward selection to construct a model to explain AS intake using participant characteristics and 14 measured CIRAAs. This model was internally validated using a bootstrap optimism correction.

Results

Median (25th, 75th percentile) AS intake was 65.2 g/d (44.7, 81.4) and 9.5% (7.2%, 12.4%) of energy. The CIR of alanine had the highest, though still modest, correlation with AS intake (Pearson r = 0.32, P = 0.001). Serum CIRAAs were more highly correlated with animal food intakes, especially the ratio of animal to total protein intake (APR). The highest correlations were between the APR and the CIRs of phenylalanine (Pearson r = 0.85, P < 0.001) and leucine (Pearson r = 0.84, P < 0.001). The model of AS intake included participant sex and body weight and the CIRs of 6 AAs: alanine, valine, lysine, glutamic acid, serine, and glycine. This model had modest explanatory power (multiple R2 = 0.38), and the optimism-corrected R2 for the model was lower (R2 = 0.15).

Conclusions

The observed association between serum CIRAAs and AS intake in the U.S. diet is encouraging; however, further investigation in populations with wider ranges of AS intake is warranted.

Funding Sources

National Cancer Institute; Institutional Development Award (IDeA) from the National Institutes of General Medical Sciences.

Protection by a Fourth Dose of BNT162b2 against Omicron in Israel

BACKGROUND

On January 2, 2022, Israel began administering a fourth dose of BNT162b2 vaccine to persons 60 years of age or older. Data are needed regarding the effect of the fourth dose on rates of confirmed severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection and of severe coronavirus disease 2019 (Covid-19).

METHODS

Using the Israeli Ministry of Health database, we extracted data on 1,252,331 persons who were 60 years of age or older and eligible for the fourth dose during a period in which the B.1.1.529 (omicron) variant of SARS-CoV-2 was predominant (January 10 through March 2, 2022). We estimated the rate of confirmed infection and severe Covid-19 as a function of time starting at 8 days after receipt of a fourth dose (four-dose groups) as compared with that among persons who had received only three doses (three-dose group) and among persons who had received a fourth dose 3 to 7 days earlier (internal control group). For the estimation of rates, we used quasi-Poisson regression with adjustment for age, sex, demographic group, and calendar day.

RESULTS

The number of cases of severe Covid-19 per 100,000 person-days (unadjusted rate) was 1.5 in the aggregated four-dose groups, 3.9 in the three-dose group, and 4.2 in the internal control group. In the quasi-Poisson analysis, the adjusted rate of severe Covid-19 in the fourth week after receipt of the fourth dose was lower than that in the three-dose group by a factor of 3.5 (95% confidence interval [CI], 2.7 to 4.6) and was lower than that in the internal control group by a factor of 2.3 (95% CI, 1.7 to 3.3). Protection against severe illness did not wane during the 6 weeks after receipt of the fourth dose. The number of cases of confirmed infection per 100,000 person-days (unadjusted rate) was 177 in the aggregated four-dose groups, 361 in the three-dose group, and 388 in the internal control group. In the quasi-Poisson analysis, the adjusted rate of confirmed infection in the fourth week after receipt of the fourth dose was lower than that in the three-dose group by a factor of 2.0 (95% CI, 1.9 to 2.1) and was lower than that in the internal control group by a factor of 1.8 (95% CI, 1.7 to 1.9). However, this protection waned in later weeks.

CONCLUSIONS

Rates of confirmed SARS-CoV-2 infection and severe Covid-19 were lower after a fourth dose of BNT162b2 vaccine than after only three doses. Protection against confirmed infection appeared short-lived, whereas protection against severe illness did not wane during the study period.

Rapid Decline of Zika Virus IgM Antibodies against the NS1 Protein in Imported Israeli Cases

Zika virus (ZIKV) infection during pregnancy may cause severe fetal abnormalities and therefore it is important to diagnose and distinguish between recent and past Zika infection. Serological diagnosis assays detect antibodies against the envelope protein, that suffer from high cross-reactivity. In addition, reports regarding long IgM persistence prevent its use in diagnosis of recent Zika infection. Following the Zika pandemic, a novel ELISA assay based on detection of IgM and IgG antibodies against Zika nonstructural 1 (NS1) protein was developed (NS1-IgM and NS1-IgG). Here, antibodies against NS1 were assessed in Israeli travelers diagnosed with Zika. NS1-IgM and NS1-IgG antibodies from 36 travelers diagnosed with ZIKV infection were detected as early as 5 days after symptom onset. However, while IgG levels were maintained for several months, IgM levels in all samples declined rapidly and by 31 days after symptom onset, no IgM positive samples were detected. Interval-censored survival analysis demonstrated 25%, 50%, and 75% decline in NS1-IgM levels in 29 days (95% CI: 22-34), 34 days (95% CI: 29-44), and 44 days (95% CI: 34-65), respectively. Our results suggest that IgM antibodies against ZIKV NS1 are short lived and can be used as a reliable marker for diagnosis of recent ZIKV infection.

Similarity of Protection Conferred by Previous SARS-CoV-2 Infection and by BNT162b2 Vaccine: A 3-Month Nationwide Experience From Israel

The worldwide shortage of vaccination against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection while the pandemic still remains uncontrolled has led many countries to the dilemma of whether or not to vaccinate previously infected persons. Understanding the level of protection conferred by previous infection compared with that of vaccination is important for policy-making. We analyzed an updated individual-level database of the entire population of Israel to assess the protection provided by both prior infection and vaccination in preventing subsequent SARS-CoV-2 infection, hospitalization with coronavirus disease 2019 (COVID-19), severe disease, and death due to COVID-19. Outcome data were collected from December 20, 2020, to March 20, 2021. Vaccination was highly protective, with overall estimated effectiveness of 94.5% (95% confidence interval (CI): 94.3, 94.7) for documented infection, 95.8% (95% CI: 95.2, 96.2) for hospitalization, 96.3% (95% CI: 95.7, 96.9) for severe illness, and 96.0% (95% CI: 94.9, 96.9) for death. Similarly, the overall estimated level of protection provided by prior SARS-CoV-2 infection was 94.8% (95% CI: 94.4, 95.1) for documented infection, 94.1% (95% CI: 91.9, 95.7) for hospitalization, and 96.4% (95% CI: 92.5, 98.3) for severe illness. Our results should be considered by policy-makers when deciding whether or not to prioritize vaccination of previously infected adults.

Comparing Covid-19 pandemic waves in hospitalized patients - a retrospective, multicenter, cohort study

BACKGROUND

Covid-19 disease was first diagnosed in Israel at the end of February 2020. Until the end of June 2021 842,536 confirmed cases and 6428 deaths were accumulated. The aim of our multicenter retrospective cohort study is to describe the demographic and clinical characteristics of hospitalized patients and to compare the pandemic waves before immunization.

METHODS

Out of 22302 patients hospitalized in general medical centers we randomly selected 6329 admissions for the study. Of these, 3582 and 1106 were eligible for the study in the first period (1 ^st & 2 ^nd waves), and in the second period (3 ^rd wave), respectively.

RESULTS

Thirty-day mortality was higher in the 2nd period than in the 1st period, 25.20% versus 13.68% (P<0.001). Invasive mechanical ventilation supported 9.19% and 14.21% of the patients in the 1st period and 2nd period, respectively. Extracorporeal Membrane Oxygenation (ECMO) was used more than twice as often on the 2nd period .

CONCLUSIONS

Invasive ventilation, use of ECMO and mortality rate were 1.5 to 2 times higher on the 2 ^nd period than in the 1 ^st period. Patients of the 2 ^nd period had a more severe presentation and higher mortality than those of the 1 ^st period.

Protection against Covid-19 by BNT162b2 Booster across Age Groups

BACKGROUND

After promising initial results from the administration of a third (booster) dose of the BNT162b2 messenger RNA vaccine (Pfizer-BioNTech) to persons 60 years of age or older, the booster campaign in Israel was gradually expanded to persons in younger age groups who had received a second dose at least 5 months earlier.

METHODS

We extracted data for the period from July 30 to October 10, 2021, from the Israel Ministry of Health database regarding 4,696,865 persons 16 years of age or older who had received two doses of BNT162b2 at least 5 months earlier. In the primary analysis, we compared the rates of confirmed coronavirus disease 2019 (Covid-19), severe illness, and death among those who had received a booster dose at least 12 days earlier (booster group) with the rates among those who had not received a booster (nonbooster group). In a secondary analysis, we compared the rates in the booster group with the rates among those who had received a booster 3 to 7 days earlier (early postbooster group). We used Poisson regression models to estimate rate ratios after adjusting for possible confounding factors.

RESULTS

The rate of confirmed infection was lower in the booster group than in the nonbooster group by a factor of approximately 10 (range across five age groups, 9.0 to 17.2) and was lower in the booster group than in the early postbooster group by a factor of 4.9 to 10.8. The adjusted rate difference ranged from 57.0 to 89.5 infections per 100,000 person-days in the primary analysis and from 34.4 to 38.3 in the secondary analysis. The rates of severe illness in the primary and secondary analyses were lower in the booster group by a factor of 17.9 (95% confidence interval [CI], 15.1 to 21.2) and 6.5 (95% CI, 5.1 to 8.2), respectively, among those 60 years of age or older and by a factor of 21.7 (95% CI, 10.6 to 44.2) and 3.7 (95% CI, 1.3 to 10.2) among those 40 to 59 years of age. The adjusted rate difference in the primary and secondary analyses was 5.4 and 1.9 cases of severe illness per 100,000 person-days among those 60 years of age or older and 0.6 and 0.1 among those 40 to 59 years of age. Among those 60 years of age or older, mortality was lower by a factor of 14.7 (95% CI, 10.0 to 21.4) in the primary analysis and 4.9 (95% CI, 3.1 to 7.9) in the secondary analysis. The adjusted rate difference in the primary and secondary analyses was 2.1 and 0.8 deaths per 100,000 person-days.

CONCLUSIONS

Across the age groups studied, rates of confirmed Covid-19 and severe illness were substantially lower among participants who received a booster dose of the BNT162b2 vaccine than among those who did not.

Waning Immunity after the BNT162b2 Vaccine in Israel

BACKGROUND

In December 2020, Israel began a mass vaccination campaign against coronavirus disease 2019 (Covid-19) by administering the BNT162b2 vaccine, which led to a sharp curtailing of the outbreak. After a period with almost no cases of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection, a resurgent Covid-19 outbreak began in mid-June 2021. Possible reasons for the resurgence were reduced vaccine effectiveness against the delta (B.1.617.2) variant and waning immunity. The extent of waning immunity of the vaccine against the delta variant in Israel is unclear.

METHODS

We used data on confirmed infection and severe disease collected from an Israeli national database for the period of July 11 to 31, 2021, for all Israeli residents who had been fully vaccinated before June 2021. We used a Poisson regression model to compare rates of confirmed SARS-CoV-2 infection and severe Covid-19 among persons vaccinated during different time periods, with stratification according to age group and with adjustment for possible confounding factors.

RESULTS

Among persons 60 years of age or older, the rate of infection in the July 11-31 period was higher among persons who became fully vaccinated in January 2021 (when they were first eligible) than among those fully vaccinated 2 months later, in March (rate ratio, 1.6; 95% confidence interval [CI], 1.3 to 2.0). Among persons 40 to 59 years of age, the rate ratio for infection among those fully vaccinated in February (when they were first eligible), as compared with 2 months later, in April, was 1.7 (95% CI, 1.4 to 2.1). Among persons 16 to 39 years of age, the rate ratio for infection among those fully vaccinated in March (when they were first eligible), as compared with 2 months later, in May, was 1.6 (95% CI, 1.3 to 2.0). The rate ratio for severe disease among persons fully vaccinated in the month when they were first eligible, as compared with those fully vaccinated in March, was 1.8 (95% CI, 1.1 to 2.9) among persons 60 years of age or older and 2.2 (95% CI, 0.6 to 7.7) among those 40 to 59 years of age; owing to small numbers, the rate ratio could not be calculated among persons 16 to 39 years of age.

CONCLUSIONS

These findings indicate that immunity against the delta variant of SARS-CoV-2 waned in all age groups a few months after receipt of the second dose of vaccine.

Waning Immunity after the BNT162b2 Vaccine in Israel

BACKGROUND

In December 2020, Israel began a mass vaccination campaign against coronavirus disease 2019 (Covid-19) by administering the BNT162b2 vaccine, which led to a sharp curtailing of the outbreak. After a period with almost no cases of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection, a resurgent Covid-19 outbreak began in mid-June 2021. Possible reasons for the resurgence were reduced vaccine effectiveness against the delta (B.1.617.2) variant and waning immunity. The extent of waning immunity of the vaccine against the delta variant in Israel is unclear.

METHODS

We used data on confirmed infection and severe disease collected from an Israeli national database for the period of July 11 to 31, 2021, for all Israeli residents who had been fully vaccinated before June 2021. We used a Poisson regression model to compare rates of confirmed SARS-CoV-2 infection and severe Covid-19 among persons vaccinated during different time periods, with stratification according to age group and with adjustment for possible confounding factors.

RESULTS

Among persons 60 years of age or older, the rate of infection in the July 11-31 period was higher among persons who became fully vaccinated in January 2021 (when they were first eligible) than among those fully vaccinated 2 months later, in March (rate ratio, 1.6; 95% confidence interval [CI], 1.3 to 2.0). Among persons 40 to 59 years of age, the rate ratio for infection among those fully vaccinated in February (when they were first eligible), as compared with 2 months later, in April, was 1.7 (95% CI, 1.4 to 2.1). Among persons 16 to 39 years of age, the rate ratio for infection among those fully vaccinated in March (when they were first eligible), as compared with 2 months later, in May, was 1.6 (95% CI, 1.3 to 2.0). The rate ratio for severe disease among persons fully vaccinated in the month when they were first eligible, as compared with those fully vaccinated in March, was 1.8 (95% CI, 1.1 to 2.9) among persons 60 years of age or older and 2.2 (95% CI, 0.6 to 7.7) among those 40 to 59 years of age; owing to small numbers, the rate ratio could not be calculated among persons 16 to 39 years of age.

CONCLUSIONS

These findings indicate that immunity against the delta variant of SARS-CoV-2 waned in all age groups a few months after receipt of the second dose of vaccine.

Waning Immune Humoral Response to BNT162b2 Covid-19 Vaccine over 6 Months

BACKGROUND

Despite high vaccine coverage and effectiveness, the incidence of symptomatic infection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has been increasing in Israel. Whether the increasing incidence of infection is due to waning immunity after the receipt of two doses of the BNT162b2 vaccine is unclear.

METHODS

We conducted a 6-month longitudinal prospective study involving vaccinated health care workers who were tested monthly for the presence of anti-spike IgG and neutralizing antibodies. Linear mixed models were used to assess the dynamics of antibody levels and to determine predictors of antibody levels at 6 months.

RESULTS

The study included 4868 participants, with 3808 being included in the linear mixed-model analyses. The level of IgG antibodies decreased at a consistent rate, whereas the neutralizing antibody level decreased rapidly for the first 3 months with a relatively slow decrease thereafter. Although IgG antibody levels were highly correlated with neutralizing antibody titers (Spearman's rank correlation between 0.68 and 0.75), the regression relationship between the IgG and neutralizing antibody levels depended on the time since receipt of the second vaccine dose. Six months after receipt of the second dose, neutralizing antibody titers were substantially lower among men than among women (ratio of means, 0.64; 95% confidence interval [CI], 0.55 to 0.75), lower among persons 65 years of age or older than among those 18 to less than 45 years of age (ratio of means, 0.58; 95% CI, 0.48 to 0.70), and lower among participants with immunosuppression than among those without immunosuppression (ratio of means, 0.30; 95% CI, 0.20 to 0.46).

CONCLUSIONS

Six months after receipt of the second dose of the BNT162b2 vaccine, humoral response was substantially decreased, especially among men, among persons 65 years of age or older, and among persons with immunosuppression.

BNT162b2 vaccine effectiveness was marginally affected by the SARS-CoV-2 beta variant in fully vaccinated individuals

Objective

To evaluate the effectiveness of the Pfizer BNT162b2 vaccine against the SARS-Cov-2 Beta variant.

Study Design and Setting

Israel's mass vaccination program, using two doses of the Pfizer BNT162b2 vaccine, successfully curtailed the Alpha variant outbreak during winter 2020–2021, However, the virus may mutate and partially evade the immune system. To monitor this, sequencing of selected positive swab samples of interest was initiated. Comparing vaccinated with unvaccinated PCR positive persons, we estimated the odds ratio for a vaccinated case to have the Beta vs. the Alpha variant, using logistic regression, controlling for important confounders.

Results

There were 19 cases of Beta variant (3.2%) among those vaccinated more than 14 days before the positive sample and 79 (3.4%) among the unvaccinated. The estimated odds ratio was 1.26 (95% CI: 0.65–2.46). Assuming the effectiveness against the Alpha variant to be 95%, the estimated effectiveness against the Beta variant was 94% (95% CI: 88%–98%).

Conclusion

Despite concerns over the Beta variant, the BNT162b2 vaccine seemed to provide substantial immunity against both the Beta and the Alpha variants. From 14 days following the second vaccine dose, the effectiveness of BNT162b2 vaccine was at most marginally affected by the Beta variant.

Protection of BNT162b2 Vaccine Booster against Covid-19 in Israel

BACKGROUND

On July 30, 2021, the administration of a third (booster) dose of the BNT162b2 messenger RNA vaccine (Pfizer-BioNTech) was approved in Israel for persons who were 60 years of age or older and who had received a second dose of vaccine at least 5 months earlier. Data are needed regarding the effect of the booster dose on the rate of confirmed coronavirus 2019 disease (Covid-19) and the rate of severe illness.

METHODS

We extracted data for the period from July 30 through August 31, 2021, from the Israeli Ministry of Health database regarding 1,137,804 persons who were 60 years of age or older and had been fully vaccinated (i.e., had received two doses of BNT162b2) at least 5 months earlier. In the primary analysis, we compared the rate of confirmed Covid-19 and the rate of severe illness between those who had received a booster injection at least 12 days earlier (booster group) and those who had not received a booster injection (nonbooster group). In a secondary analysis, we evaluated the rate of infection 4 to 6 days after the booster dose as compared with the rate at least 12 days after the booster. In all the analyses, we used Poisson regression after adjusting for possible confounding factors.

RESULTS

At least 12 days after the booster dose, the rate of confirmed infection was lower in the booster group than in the nonbooster group by a factor of 11.3 (95% confidence interval [CI], 10.4 to 12.3); the rate of severe illness was lower by a factor of 19.5 (95% CI, 12.9 to 29.5). In a secondary analysis, the rate of confirmed infection at least 12 days after vaccination was lower than the rate after 4 to 6 days by a factor of 5.4 (95% CI, 4.8 to 6.1).

CONCLUSIONS

In this study involving participants who were 60 years of age or older and had received two doses of the BNT162b2 vaccine at least 5 months earlier, we found that the rates of confirmed Covid-19 and severe illness were substantially lower among those who received a booster (third) dose of the BNT162b2 vaccine.

Protection of BNT162b2 Vaccine Booster against Covid-19 in Israel

BACKGROUND

On July 30, 2021, the administration of a third (booster) dose of the BNT162b2 messenger RNA vaccine (Pfizer-BioNTech) was approved in Israel for persons who were 60 years of age or older and who had received a second dose of vaccine at least 5 months earlier. Data are needed regarding the effect of the booster dose on the rate of confirmed coronavirus 2019 disease (Covid-19) and the rate of severe illness.

METHODS

We extracted data for the period from July 30 through August 31, 2021, from the Israeli Ministry of Health database regarding 1,137,804 persons who were 60 years of age or older and had been fully vaccinated (i.e., had received two doses of BNT162b2) at least 5 months earlier. In the primary analysis, we compared the rate of confirmed Covid-19 and the rate of severe illness between those who had received a booster injection at least 12 days earlier (booster group) and those who had not received a booster injection (nonbooster group). In a secondary analysis, we evaluated the rate of infection 4 to 6 days after the booster dose as compared with the rate at least 12 days after the booster. In all the analyses, we used Poisson regression after adjusting for possible confounding factors.

RESULTS

At least 12 days after the booster dose, the rate of confirmed infection was lower in the booster group than in the nonbooster group by a factor of 11.3 (95% confidence interval [CI], 10.4 to 12.3); the rate of severe illness was lower by a factor of 19.5 (95% CI, 12.9 to 29.5). In a secondary analysis, the rate of confirmed infection at least 12 days after vaccination was lower than the rate after 4 to 6 days by a factor of 5.4 (95% CI, 4.8 to 6.1).

CONCLUSIONS

In this study involving participants who were 60 years of age or older and had received two doses of the BNT162b2 vaccine at least 5 months earlier, we found that the rates of confirmed Covid-19 and severe illness were substantially lower among those who received a booster (third) dose of the BNT162b2 vaccine.

BNT162b2 COVID-19 vaccine and correlates of humoral immune responses and dynamics: a prospective, single-centre, longitudinal cohort study in health-care workers

Background

Concurrent with the Pfizer–BioNTech BNT162b2 COVID-19 vaccine roll-out in Israel initiated on Dec 19, 2020, we assessed the early antibody responses and antibody kinetics after each vaccine dose in health-care workers of different ages and sexes, and with different comorbidities.

Methods

We did a prospective, single-centre, longitudinal cohort study at the Sheba Medical Centre (Tel-Hashomer, Israel). Eligible participants were health-care workers at the centre who had a negative anti-SARS-CoV-2 IgG assay before receiving the first dose of the intramuscular vaccine, and at least one serological antibody test after the first dose of the vaccine. Health-care workers with a positive SARS-CoV-2 PCR test before vaccination, a positive anti-SARS-CoV-2 IgG serology test before vaccination, or infection with COVID-19 after vaccination were excluded from the study. Participants were followed up weekly for 5 weeks after the first vaccine dose; a second dose was given at week 3. Serum samples were obtained at baseline and at each weekly follow-up, and antibodies were tested at 1–2 weeks after the first vaccine dose, at week 3 with the administration of the second vaccine dose, and at weeks 4–5 (ie, 1–2 weeks after the second vaccine dose). Participants with comorbidities were approached to participate in an enriched comorbidities subgroup, and at least two neutralising assays were done during the 5 weeks of follow-up in those individuals. IgG assays were done for the entire study population, whereas IgM, IgA, and neutralising antibody assays were done only in the enriched comorbidities subgroup. Concentrations of IgG greater than 0·62 sample-to-cutoff (s/co) ratio and of IgA greater than 1·1 s/co, and titres of neutralising antibodies greater than 10 were considered positive. Scatter plot and correlation analyses, logistic and linear regression analyses, and linear mixed models were used to investigate the longitudinal antibody responses.

Findings

Between Dec 19, 2020, and Jan 30, 2021, we obtained 4026 serum samples from 2607 eligible, vaccinated participants. 342 individuals were included in the enriched comorbidities subgroup. The first vaccine dose elicited positive IgG and neutralising antibody responses at week 3 in 707 (88·0%) of 803 individuals, and 264 (71·0%) of 372 individuals, respectively, which were rapidly increased at week 4 (ie, 1 week after the second vaccine dose) in 1011 (98·4%) of 1027 and 357 (96·5%) of 370 individuals, respectively. Over 4 weeks of follow-up after vaccination, a high correlation (r=0·92) was detected between IgG against the receptor-binding domain and neutralising antibody titres. First-dose induced IgG response was significantly lower in individuals aged 66 years and older (ratio of means 0·25, 95% CI 0·19–0·31) and immunosuppressed individuals (0·21, 0·14–0·31) compared with individuals aged 18·00–45·99 years and individuals with no immunosuppression, respectively. This disparity was partly abrogated following the second dose. Overall, endpoint regression analysis showed that lower antibody concentrations were consistently associated with male sex (ratio of means 0·84, 95% CI 0·80–0·89), older age (ie, ≥66 years; 0·64, 0·58–0·71), immunosuppression (0·44, 0·33–0·58), and other specific comorbidities: diabetes (0·88, 0·79–0·98), hypertension (0·90, 0·82–0·98), heart disease (0·86, 0·75–1·00), and autoimmune diseases (0·82, 0·73–0·92).

Interpretation

BNT162b2 vaccine induces a robust and rapid antibody response. The significant correlation between receptor-binding domain IgG antibodies and neutralisation titres suggests that IgG antibodies might serve as a correlate of neutralisation. The second vaccine dose is particularly important for older and immunosuppressed individuals, highlighting the need for timely second vaccinations and potentially a revaluation of the long gap between doses in some countries. Antibody responses were reduced in susceptible populations and therefore they might be more prone to breakthrough infections.

Funding

Sheba Medical Center, Israel Ministry of Health.

The Carbon Isotope Ratio of Breath Is Elevated by Short and Long-Term Added Sugar and Animal Protein Intake in a Controlled Feeding Study

Objectives

Objective biomarkers would help to clarify relationships between added sugar (AS) intake and chronic disease. A recent study identified the breath carbon isotope ratio (CIR) as a potential short-term AS biomarker. To further evaluate the biomarker potential of the breath CIR, we evaluate the effects of both short and longer-term intakes of AS in the context of normal dietary intake patterns, and also evaluate animal protein (AP), another dietary factor known to influence CIR.

Methods

We conducted a 15-d controlled feeding study of 100 adults (age 18–70, 55% women) in Phoenix, AZ. Participants were provided individualized diets that approximated habitual food intakes and recorded the time that all foods were consumed throughout each day. Three breath samples were collected on each of 3 nonconsecutive, randomly selected study days: one fasting sample, one “morning” sample (collected 10:00–14:00) and one “evening” sample (collected 14:00–20:00). We used a linear mixed model to evaluate the effects of AS and AP intake in each of 8 hours preceding collection of the breath sample (t1 = 0–1 hour prior, t2 = 1–2 hours prior, etc.). Besides daily intake, models also included 15-d mean AS and AP intake, as well as sex, age and BMI. Coefficients are presented as (β (SE), P).

Results

Mean (±SD) intakes of AS and AP in our study were 67 ± 34 and 73 ± 30 g/d, respectively. The breath CIR was increased by AS consumed 1–4 hours prior to sample collection (βt2 = 0.014 (0.005), P = 0.0025; βt3 = 0.0094 (0.004), P = 0.02; βt4 = 0.012 (0.005), P = 0.02) and AP consumed 3–6 hours prior to sample collection (βt4 = 0.012 (0.005), P = 0.03; βt5 = 0.0092 (0.004), P = 0.03; βt6 = 0.010 (0.006), P = 0.09). In addition, the breath CIR increased with higher 15-d intakes of both AS and AP (βAS = 0.012 (0.003), P &lt; 0.0001 and βAP = 0.014 (0.004), P = 0.0003, respectively).

Conclusions

Both short-term and longer-term intakes of AS and AP increased the breath CIR. Short-term AS intake had a more rapid effect on the breath CIR than short-term AP intake, although effects were of similar size. Furthermore, the size of short-term effects were similar to the size of long-term effects. Thus, breath CIR is influenced by both short and long-term intakes of AS and AP and could have potential for evaluating dietary patterns.

Funding Sources

This work was funded by NIH U01 CA197902.

Evaluating the Serum Carbon Isotope Ratio as a Biomarker for Animal Protein Ratio in a Controlled Feeding Study of US Adults

Objectives

Recent studies have identified the serum natural abundance carbon isotope ratio (CIR) as a candidate biomarker of animal protein intake in postmenopausal women. Such a biomarker would help clarify the contribution of dietary protein source (animal vs. vegetable) to chronic disease risk. Here we evaluate biomarker performance and develop a biomarker calibration equation in a mixed-age and – gender cohort.

Methods

We conducted a 15-d feeding study of 100 adults (age 18–70, 55% women) in Phoenix, AZ. Participants were provided individualized diets that approximated habitual food intakes. Total CIR and nitrogen isotope ratio (NIR) were measured in sera collected at the end of the feeding period. We expressed animal protein as a ratio of total protein intake (APratio). We evaluated a model of serum CIR based on APratio, the serum NIR, gender, age and body weight, and the resulting regression equation was inverted to develop an equation for the APratio that we call the calibrated biomarker. We evaluated the association of the calibrated biomarker with actual APratio using Pearson correlation and 5-fold cross validation.

Results

Animal protein intake in this study was 73 ± 30 g/d (mean ± SD) and the APratio was 0.63 ± 0.13. Our model explained a large proportion of the variation in serum CIR (R2 = 0.77) and APratio was the only significant model effect (coefficient = 6.22, SE = 0.44, P &lt; 0.0001). Inverting that model generated the following biomarker calibration equation: APratio = (CIR – 26.35 – 0.06 (gender) + 0.068 * In age – 0.215 * In body weight – 0.204 * serum NIR)/6.22, where gender = 1,0 (male, female). There was a strong correlation between model-predicted and actual APratio (rP = 0.85, P &lt; 0.0001), with the mean model-predicted APratio differing from mean actual APratio by 0.0015 (SE = 0.0077). The standard deviation of the prediction error was 0.076. The 5-fold cross validation procedure produced very similar model R2, effects, and prediction errors.

Conclusions

These data suggest that the serum CIR has potential as a predictive biomarker of APratio, providing a useful tool for objectively assessing dietary protein intake patterns. Such a tool could help resolve the contribution of dietary patterns favoring animal protein intake to chronic disease risk.

Funding Sources

This work was funded by NIH U01 CA197902.

Rituximab maintenance improves overall survival of patients with follicular lymphoma-Individual patient data meta-analysis

BACKGROUND

Randomised trials of rituximab maintenance (MR) for patients with follicular lymphoma support improved progression-free survival (PFS), but the effect on overall survival has been inconclusive. To evaluate the effect of MR on overall survival according to patient and disease characteristics, and to explore certain adverse events, we performed an individual patient data (IPD) meta-analysis.

METHODS

All investigators of randomised controlled trials that compared MR therapy with observation or treatment only at relapse (no MR) for patients with follicular lymphoma were invited to participate in an IPD meta-analysis. We obtained baseline patient and disease characteristics and time to progression and death for each patient. All analyses took into account the trial and original randomised treatment group. We analysed data in two ways: a two-stage analysis and a multivariate model including patient and disease characteristics.

FINDINGS

Seven trials including 2315 patients were analysed. Overall survival of patients improved with MR compared with no MR (hazard ratio [HR] 0.79, 95% CI 0.66-0.96). We could not detect any patient or disease characteristics that were associated with a survival benefit with MR. In all of the models, MR had a beneficial effect on overall survival compared with observation for all types of patients, which was not shown in a particular subgroup in which the patient had already received rituximab in the induction phase and received first-line therapy. MR improved PFS compared with observation (HR 0.57, 95% CI 0.51-0.64). The risk of adverse events was higher with MR, specifically infection of any grade and grade 3-4 infections.

INTERPRETATION

Based on IPD from randomised controlled trials, MR improves overall survival consistently in all patients, regardless of patient and disease characteristics when compared with observation, and should be prescribed after a successful induction with R-CVP or R-CHOP for patients with follicular lymphoma. It is still uncertain if that holds when the patient has already received rituximab in his/hers first induction. The effect of MR after bendamustine-rituximab induction compared with rituximab at progression should be further explored.

Chromatic Multifocal Pupillometer for Objective Perimetry and Diagnosis of Patients with Retinitis Pigmentosa

PURPOSE

To assess visual field (VF) defects and retinal function objectively in healthy participants and patients with retinitis pigmentosa (RP) using a chromatic multifocal pupillometer.

DESIGN

Cross-sectional study.

PARTICIPANTS

The right eyes of 16 healthy participants and 13 RP patients.

METHODS

Pupil responses to red and blue light (peak, 485 and 625 nm, respectively) presented by 76 light-emitting diodes, 1.8-mm spot size at different locations of a 16.2° VF were recorded. Subjective VFs of RP patients were determined using chromatic dark-adapted Goldmann VFs (CDA-GVFs). Six healthy participants underwent 2 pupillometer examinations to determine test-retest reliability.

MAIN OUTCOME MEASURES

Three parameters of pupil contraction were determined automatically: percentage of change of pupil size (PPC), maximum contraction velocity (MCV; in pixels per second), and latency of MCV (LMCV; in seconds). The fraction of functional VF was determined by CDA-GVF.

RESULTS

In healthy participants, higher PPC and MCV were measured in response to blue compared with red light. The LMCV in response to blue light was relatively constant throughout the VF. Healthy participants demonstrated higher PPC and MCV and shorter LMCV in central compared with peripheral test points in response to red light. Test-retest correlation coefficients were 0.7 for PPC and 0.5 for MCV. In RP patients, test point in which the PPC and MCV were lower than 4 standard errors from the mean of healthy participants correlated with areas that were indicated as nonseeing by CDA-GVF. The mean absolute deviation in LMCV parameter in response to the red light between different test point was significantly higher in RP patients (range, 0.16-0.47) than in healthy participants (range, 0.02-0.16; P < 0.0001) and indicated its usefulness as a diagnostic tool with high sensitivity and specificity (area under the receiver operating characteristic curve (AUC), 0.97, Mann-Whitney-Wilcoxon analysis). Randomly reducing the number of test points to a total of 15 points did not significantly reduce the AUC in RP diagnosis based on this parameter.

CONCLUSIONS

This study demonstrates the feasibility of using a chromatic multifocal pupillometer for objective diagnosis of RP and assessment of VF defects.

Methods to Assess Measurement Error in Questionnaires of Sedentary Behavior

Sedentary behavior has already been associated with mortality, cardiovascular disease, and cancer. Questionnaires are an affordable tool for measuring sedentary behavior in large epidemiological studies. Here, we introduce and evaluate two statistical methods for quantifying measurement error in questionnaires. Accurate estimates are needed for assessing questionnaire quality. The two methods would be applied to validation studies that measure a sedentary behavior by both questionnaire and accelerometer on multiple days. The first method fits a reduced model by assuming the accelerometer is without error, while the second method fits a more complete model that allows both measures to have error. Because accelerometers tend to be highly accurate, we show that ignoring the accelerometer's measurement error, can result in more accurate estimates of measurement error in some scenarios. In this manuscript, we derive asymptotic approximations for the Mean-Squared Error of the estimated parameters from both methods, evaluate their dependence on study design and behavior characteristics, and offer an R package so investigators can make an informed choice between the two methods. We demonstrate the difference between the two methods in a recent validation study comparing Previous Day Recalls (PDR) to an accelerometer-based ActivPal.

Diabetes among Ethiopian Immigrants to Israel: Exploring the Effects of Migration and Ethnicity on Diabetes Risk

Objective

Diabetes prevalence among ethnic minorities and immigrants often differs from the majority indigenous population. We compared diabetes prevalence, incidence and risk among Ethiopian and non-Ethiopian Jews. Within these main groups, we controlled for the effect of migration on diabetes risk by comparing the subgroups of Ethiopian and former Soviet Union (FSU) immigrants, and compared both with Israeli-born non-Ethiopian Jews.

Methods

The study cohort included adult Ethiopian (n = 8,398) and age-matched non-Ethiopian Jews (n = 15,977) and subgroups: Ethiopian immigrants (n = 7,994), FSU immigrants (n = 1,541) and Israeli-born non-Ethiopian Jews (n = 10,828). Diabetes prevalence, annual incidence, and hazard ratios (HRs) adjusted for sex and metabolic syndrome (MetS)-components, were determined in three age groups (<50yrs, 50-59yrs, and ≥60yrs). Comparisons of body mass index (BMI) at diabetes incidence were made.

Results

Younger (<50yrs) Ethiopians had higher prevalence rates, 3.6% (95%CI: 3.1–4.1) and annual incidence, 0.9% (95%CI: 0.8–1.0) than non-Ethiopians, 2.7% (95%CI: 2.3–3.0) and 0.5% (95%CI: 0.4–0.6), respectively. These differences were particularly pronounced among Ethiopian women. Diabetes risk among Ethiopians was higher and adjustment for MetS-components was important only for BMI, which further increased hazard ratio (HR) estimates associated with Ethiopian ethnicity from 1.81 (95% CI:1.50–2.17) to 2.31 (95% CI:1.91–2.79). The same differences were seen when comparing Ethiopian to FSU immigrants. BMI before incident diabetes was lower among younger Ethiopian immigrants than younger FSU immigrants and Israeli-born.

Conclusions

Ethiopian ethnicity is associated with increased diabetes risk, which is age and BMI dependent. Young Ethiopians<50yrs, particularly women, had the greatest increase in risk. Lower BMI cut-offs should be defined to reflect diabetes risk among Ethiopians.

Special care dentistry: how prepared are we?

AIM

To assess and evaluate the confidence of the undergraduate dental team in Irish dental schools regarding their training in the field of special care dentistry (SCD).

METHOD

A questionnaire was distributed amongst the undergraduate dental teams within Cork University Dental School and Hospital (CUDSH) and Dublin Dental University Hospital (DDUH). The data were analysed to assess for differences between the median responses of the various groups.

RESULTS

A total of 139 students participated in the study; 82 from DDUH (59 dental science students, seven dental hygiene students and 16 dental nursing students) and 57 from CUDSH (43 dental science students and 14 dental hygiene students). Twenty-two per cent (n = 30) of respondents agreed that their training had been sufficient in providing treatment or assistance for patients requiring SCD. Seventy-five per cent agreed that more emphasis should be placed on clinical training in SCD (n = 76). Thirty-one per cent of students anticipated a high level of confidence in treating patients requiring SCD upon graduation (n = 43), with dental science students feeling the least prepared amongst the dental team.

CONCLUSION

Confidence levels of the undergraduate dental team were low with regard to SCD. The existing hands-on clinical training in SCD was deemed insufficient by the respondents. Students believed more emphasis should be placed on SCD training in the undergraduate curriculum.

Enzymatic MPG DNA repair assays for two different oxidative DNA lesions reveal associations with increased lung cancer risk

DNA repair is a major mechanism for minimizing mutations and reducing cancer risk. Here, we present the development of reproducible and specific enzymatic assays for methylpurine DNA glycosylase (MPG) repairing the oxidative lesions 1,N6-ethenoadenine (εA) and hypoxanthine (Hx) in peripheral blood mononuclear cells protein extracts. Association of these DNA repair activities with lung cancer was determined using conditional logistic regression with specimens from a population-based case-control study with 96 lung cancer cases and 96 matched control subjects. The mean MPG-εA in case patients was 15.8 units/μg protein (95% CI 15.3-16.3), significantly higher than in control subjects-15.1 (14.6-15.5), *P = 0.011. The adjusted odds ratio for lung cancer associated with a one SD increase in MPG-εA activity (2.48 units) was significantly bigger than 1 (OR = 1.6, 95% CI = 1.1-2.4; *P = 0.013). When activity of OGG1, a different DNA repair enzyme for oxidative damage, was included in the model, the estimated odds ratio/SD for a combined MPG-εA-OGG1 score was 2.6 (95% CI 1.6-4.2) *P = 0.0001, higher than the odds ratio for each single assay. The MPG enzyme activity assays described provide robust functional risk biomarkers, with increased MPG-εA activity being associated with increased lung cancer risk, similar to the behavior of MPG-Hx. This underscores the notion that imbalances in DNA repair, including high DNA repair, usually perceived as beneficial, can cause cancer risk. Such DNA repair risk biomarkers may be useful for risk assessment of lung cancer and perhaps other cancer types, and for early detection techniques such as low-dose CT.

ISS groups: are we speaking the same language?

BACKGROUND

Despite ISS being a widely accepted tool for measuring injury severity, many researchers and practitioners use different partition of ISS into severity groups. The lack of uniformity in ISS use inhibits proper comparisons between different studies. Creation of ISS group boundaries based on single AIS value squares and their sums was proposed in 1988 during Major Trauma Study (MTOS) in the USA, but was not validated by analysis of large databases.

METHODS

A validation study analysing 316,944 patients in the Israeli National Trauma registry (INTR) and 249,150 patients in the American National Trauma Data Bases (NTDB). A binary algorithm (Classification and Regression Trees (CART)) was used to detect the most significantly different ISS groups and was also applied to original MTOS data.

RESULTS

The division of ISS into groups by the CART algorithm was identical in both Trauma Registries and very similar to original division in the MTOS. For most samples, the recommended groups are 1-8, 9-14, 16-24 and 25-75, while in very large samples or in studies specifically targeting critical patients there is a possibility to divide the last group into 25-48 and 50-75 groups, with an option for further division into 50-66 and 75 groups.

CONCLUSIONS

Using a statistical analysis of two very large databases of trauma patients, we have found that partitioning of ISS into groups based on their association with patient mortality enables us to establish clear cut-off points for these groups. We propose that the suggested partition of ISS into severity groups would be adopted as a standard in order to have a common language when discussing injury severity.

The value of education in special care dentistry as a means of reducing inequalities in oral health

People with disability are subject to inequality in oral health both in terms of prevalence of disease and unmet healthcare needs. Over 18% of the global population is living with moderate to severe functional problems related to disability, and a large proportion of these persons will require Special Care Dentistry at some point in their lifetime. It is estimated that 90% of people requiring Special Care Dentistry should be able to access treatment in a local, primary care setting. Provision of such primary care is only possible through the education and training of dentists. The literature suggests that it is vital for the dental team to develop the necessary skills and gain experience treating people with special needs in order to ensure access to the provision of oral health care. Education in Special Care Dentistry worldwide might be improved by the development of a recognised academic and clinical discipline and by providing international curricula guidelines based on the International Classification of Functioning, Disability and Health (ICF, WHO). This article aims to discuss the role and value of promoting and harmonising education in Special Care Dentistry as a means of reducing inequalities in oral health.

N-methylpurine DNA glycosylase and OGG1 DNA repair activities: opposite associations with lung cancer risk

Only a minority of smokers develop lung cancer, possibly due to genetic predisposition, including DNA repair deficiencies. To examine whether inter-individual variations in DNA repair activity of N-methylpurine DNA glycosylase (MPG) are associated with lung cancer, we conducted a blinded, population-based, case–control study with 100 lung cancer case patients and 100 matched control subjects and analyzed the data with conditional logistic regression. All statistical tests were two-sided. MPG enzyme activity in peripheral blood mononuclear cells from case patients was higher than in control subjects, results opposite that of 8-oxoguanine DNA glycosylase (OGG1) DNA repair enzyme activity. For lung cancer associated with one standard deviation increase in MPG activity, the adjusted odds ratio was 1.8 (95% confidence interval [CI] = 1.2 to 2.6; P = .006). A combined MPG and OGG1 activities score was more strongly associated with lung cancer risk than either activity alone, with an odds ratio of 2.3 (95% CI = 1.4 to 3.6; P < .001). These results form a basis for a future panel of risk biomarkers for lung cancer risk assessment and prevention.

Efficacy of nonpharmacologic interventions for agitation in advanced dementia: a randomized, placebo-controlled trial

BACKGROUND

A randomized, placebo-controlled clinical trial was undertaken to determine the efficacy of nonpharmacologic individualized interventions (individualized to address unmet needs such as boredom or pain) in decreasing agitation in persons with dementia.

METHOD

Agitated nursing home residents with advanced dementia (from 9 nursing homes in 5 locations in Maryland, United States) were randomized into an intervention group (n = 89) and a placebo control group (n = 36). On the basis of data from baseline assessment, a systematic methodology for individualizing nonpharmacologic interventions, Treatment Routes for Exploring Agitation (TREA), was used with the intervention group: an unmet need was hypothesized, a corresponding treatment category was identified, and specifics of the treatment were chosen to fit the person's need, past identity, preferences, and abilities. (Unmet needs were hypothesized based on physician evaluations, structured staff interviews, relative questionnaires, direct observations of agitation with the Agitation Behavior Mapping Instrument [the primary outcome measure] and affect with Lawton's Modified Behavior Stream [the secondary outcome measure], and resident assessments.) TREA interventions were implemented for 2 weeks, and observations of agitation and affect were recorded. The study was conducted from June 2006 until December 2011.

RESULTS

Relative to a control group, TREA interventions for unmet needs produced statistically significant declines in total (P < .001), physical nonaggressive (P < .001), and verbal agitation (P = .004) and significant increases in pleasure (P < .001) and interest (P < .05).

CONCLUSIONS

This is the first large randomized controlled trial to demonstrate the efficacy of TREA and one of only a few such trials of nonpharmacologic interventions for agitation in persons with dementia. The translation of these findings into practice is sorely needed and would require structural changes dedicating staff time to observing each agitated resident, determining unmet needs, obtaining appropriate intervention materials, conducting the individualized nonpharmacologic interventions, and evaluating results.

TRIAL REGISTRATION

ClinicalTrials.gov identifier: NCT00820859.

Diabetes, glucose control, glucose lowering medications, and cancer risk: a 10-year population-based historical cohort

Background

Both diabetes and glucose-lowering medications have been associated with an increased risk of cancer incidence. This study will compare cancer incidence rates in individuals with and without diabetes; and will investigate, in individuals with diabetes, an association between glucose control and cancer incidence; and between the use of specific glucose-lowering medications, as well as no drug exposure, and cancer incidence.

Methods/design

This is a population based historical cohort study of all individuals aged 21 years or older (about 2,300,000) who were insured by Clalit Health Services, the largest health maintenance organization in Israel during a ten-year study period. Four study groups will be established according to the status of diabetes and cancer at study entry, Jan 1, 2002: cancer free, diabetes free; cancer free, diabetes prevalent; cancer prevalent, diabetes free; and cancer prevalent, diabetes prevalent. Individuals without diabetes at study entry will be followed for diabetes incidence, and all four groups will be followed for specific cancer incidence, including second primary neoplasms. Glucose control will be assessed by HbA1c and by fasting plasma glucose levels. Time dependent regression models for cancer incidence will account for glucose-lowering medications as they are added and changed over the follow-up period. A large number of demographic and clinical variables will be considered, including: age, gender, BMI, smoking status, concomitant medications, glucose control (assessed by HbA1c and by fasting plasma glucose) and cancer screening tests.

Discussion

Strengths of this study include the large population; high quality comprehensive data; comparison to individuals without diabetes, and to those with diabetes but not treated with glucose-lowering medications; and the extensive range of variables available for analysis. The great increases in diabetes prevalence and in treatment options render this study particularly relevant and timely. The Israeli national healthcare system, characterized by high standard and uniform healthcare, offers an advantageous environment for its conduct.

Candidate gene analysis in israeli soldiers with stress fractures

To investigate the association of polymorphisms within candidate genes which we hypothesized may contribute to stress fracture predisposition, a case-control, cross- sectional study design was employed. Genotyping 268 Single Nucleotide Polymorphisms- SNPs within 17 genes in 385 Israeli young male and female recruits (182 with and 203 without stress fractures). Twenty-five polymorphisms within 9 genes (NR3C1, ANKH, VDR, ROR2, CALCR, IL6, COL1A2, CBG, and LRP4) showed statistically significant differences (p < 0.05) in the distribution between stress fracture cases and non stress fracture controls. Seventeen genetic variants were associated with an increased stress fracture risk, and eight variants with a decreased stress fracture risk. None of the SNP associations remained significant after correcting for multiple comparisons (false discovery rate- FDR). Our findings suggest that genes may be involved in stress fracture pathogenesis. Specifically, the CALCR and the VDR genes are intriguing candidates. The putative involvement of these genes in stress fracture predisposition requires analysis of more cases and controls and sequencing the relevant genomic regions, in order to define the specific gene mutations. Key pointsUnderstanding the possible contribution of genetic variants to stress fracture pathogenesis.There is a paucity of data on the involvement of polymorphisms in specific genes in active military personnel/athletes which may contribute to stress fractures development.The results from the current study should facilitate a more comprehensive look at the genetic component of stress fractures.

Childhood exposure to ionizing radiation to the head and risk of schizophrenia

While the association between exposure to ionizing radiation and cancer is well established, its association with schizophrenia is unclear. The aim of our study was to assess risk of schizophrenia after childhood exposure to ionizing radiation to the head (mean dose: 1.5 Gy). The study population included an exposed group of 10,834 individuals irradiated during childhood for treatment of tinea capitis in the 1950s and two unexposed comparison groups of 5392 siblings and 10,834 subjects derived from the National Population Registry individually matched to the exposed group by age, sex (when possible), country of birth, and year of immigration to Israel. These groups were followed for a median 46 years for diagnosis of schizophrenia updated to December 2002. The Cox proportional hazards model stratified by matched sets was used to compare the risk of schizophrenia between the groups. Based on 1,217,531 person-years of follow-up, 451 cases were identified. No statistically significant association was found between radiation exposure and schizophrenia for the total group (hazard ratio per 1 Gy to the brain: 1.05, 95% confidence interval: 0.93-1.18) or within subgroups of sex, dose categories or latent period. When comparing a subgroup of subjects irradiated under 5 years of age with the matched unexposed group, the estimated hazard ratio reached 1.18 (95% confidence interval: 0.96-1.44; P = 0.1). The results of our analysis do not support an association between exposure to ionizing radiation and risk of schizophrenia. More research on possible effects of early exposure to ionizing radiation on schizophrenia specifically and brain tissue in general is needed.

A NEW MULTIVARIATE MEASUREMENT ERROR MODEL WITH ZERO-INFLATED DIETARY DATA, AND ITS APPLICATION TO DIETARY ASSESSMENT

In the United States the preferred method of obtaining dietary intake data is the 24-hour dietary recall, yet the measure of most interest is usual or long-term average daily intake, which is impossible to measure. Thus, usual dietary intake is assessed with considerable measurement error. Also, diet represents numerous foods, nutrients and other components, each of which have distinctive attributes. Sometimes, it is useful to examine intake of these components separately, but increasingly nutritionists are interested in exploring them collectively to capture overall dietary patterns. Consumption of these components varies widely: some are consumed daily by almost everyone on every day, while others are episodically consumed so that 24-hour recall data are zero-inflated. In addition, they are often correlated with each other. Finally, it is often preferable to analyze the amount of a dietary component relative to the amount of energy (calories) in a diet because dietary recommendations often vary with energy level. The quest to understand overall dietary patterns of usual intake has to this point reached a standstill. There are no statistical methods or models available to model such complex multivariate data with its measurement error and zero inflation. This paper proposes the first such model, and it proposes the first workable solution to fit such a model. After describing the model, we use survey-weighted MCMC computations to fit the model, with uncertainty estimation coming from balanced repeated replication.The methodology is illustrated through an application to estimating the population distribution of the Healthy Eating Index-2005 (HEI-2005), a multi-component dietary quality index involving ratios of interrelated dietary components to energy, among children aged 2-8 in the United States. We pose a number of interesting questions about the HEI-2005 and provide answers that were not previously within the realm of possibility, and we indicate ways that our approach can be used to answer other questions of importance to nutritional science and public health.

Can agitated behavior of nursing home residents with dementia be prevented with the use of standardized stimuli?

OBJECTIVES

To assess the relative effect of different types of stimuli on agitated behaviors of nursing home residents with dementia.

DESIGN

Repeated-measures design with randomized assignment of conditions.

SETTING

Seven Maryland nursing homes.

PARTICIPANTS

One hundred eleven nursing home residents with a diagnosis of dementia who exhibited agitation.

INTERVENTION

Different types of stimuli (music, social stimuli, simulated social stimuli, and individualized stimuli based on the person's self-identity) were presented.

MEASUREMENTS

Agitation was directly observed and recorded using the Agitation Behavior Mapping Instrument.

RESULTS

All stimulus categories were associated with significantly less physical agitation than baseline observations, and all except for manipulative stimuli were associated with significantly less total agitation. Live social stimuli were associated with less agitation than music, self-identity, work, simulated social, and manipulative stimulus categories. Task and reading stimulus categories were each associated with significantly less agitation than work, simulated social, and manipulative stimulus categories. Music and self-identity stimuli were associated with less agitation than simulated social and manipulative stimuli.

CONCLUSION

Providing stimuli offers a proactive approach to preventing agitation in persons with dementia, with live social stimuli being the most successful.

Traumeel S for pain relief following hallux valgus surgery: a randomized controlled trial

Background

In spite of recent advances in post-operative pain relief, pain following orthopedic surgery remains an ongoing challenge for clinicians. We examined whether a well known and frequently prescribed homeopathic preparation could mitigate post-operative pain.

Method

We performed a randomized, double blind, placebo-controlled trial to evaluate the efficacy of the homeopathic preparation Traumeel S^® in minimizing post-operative pain and analgesic consumption following surgical correction of hallux valgus. Eighty consecutive patients were randomized to receive either Traumeel tablets or an indistinguishable placebo, and took primary and rescue oral analgesics as needed. Maximum numerical pain scores at rest and consumption of oral analgesics were recorded on day of surgery and for 13 days following surgery.

Results

Traumeel was not found superior to placebo in minimizing pain or analgesic consumption over the 14 days of the trial, however a transient reduction in the daily maximum post-operative pain score favoring the Traumeel arm was observed on the day of surgery, a finding supported by a treatment-time interaction test (p = 0.04).

Conclusions

Traumeel was not superior to placebo in minimizing pain or analgesic consumption over the 14 days of the trial. A transient reduction in the daily maximum post-operative pain score on the day of surgery is of questionable clinical importance.

Trial Registration

This study was registered at ClinicalTrials.gov. # NCT00279513

Cellular phone use and risk of benign and malignant parotid gland tumors--a nationwide case-control study

The objective of this nationwide study was to assess the association between cellular phone use and development of parotid gland tumors (PGTs). The methods were based on the international INTERPHONE study that aimed to evaluate possible adverse effects of cellular phone use. The study included 402 benign and 58 malignant incident cases of PGTs diagnosed in Israel at age 18 years or more, in 2001-2003, and 1,266 population individually matched controls. For the entire group, no increased risk of PGTs was observed for ever having been a regular cellular phone user (odds ratio = 0.87; p = 0.3) or for any other measure of exposure investigated. However, analysis restricted to regular users or to conditions that may yield higher levels of exposure (e.g., heavy use in rural areas) showed consistently elevated risks. For ipsilateral use, the odds ratios in the highest category of cumulative number of calls and call time without use of hands-free devices were 1.58 (95% confidence interval: 1.11, 2.24) and 1.49 (95% confidence interval: 1.05, 2.13), respectively. The risk for contralateral use was not significantly different from 1. A positive dose-response trend was found for these measurements. Based on the largest number of benign PGT patients reported to date, our results suggest an association between cellular phone use and PGTs.

Does greater exposure to own-health data make a difference on the visual analog scale?

The Visual Analog Scale (VAS) has become popular in eliciting valuation of health-related quality of life. The aim of the study was to explore the effect of greater exposure to own-health data on the VAS evaluation. A survey of 2,500 individuals included three measurements of the VAS, which differed in time and in the accumulated recall data to which the respondent had been exposed. Agreement among the three measurements was tested in several ways. The results generally showed that the VAS is a stable measure. The intraclass correlation coefficient (ICC) was 0.881. The paired t-tests indicated that the differences between the measurements were insignificant. More than half of the sample reported exactly the same VAS value in the three measurements. The use of the VAS measure, without any other preparation, seems to invoke the own-health data needed to report an accurate evaluation of health-related quality of life at any point in time.

Quantitative science methods for biomarker validation in chemoprevention trials

Even the most common malignancies have a low probability of occurrence over a restricted time interval. Therefore controlled intervention studies that use incident cancer as an outcome must be large, lengthy and, hence, costly. Studies with surrogate outcomes - biomarkers of pre-clinical carcinogenesis - are attractive because they are potentially smaller, shorter, and less expensive than their counterparts with cancer outcomes. Despite their potential, however, surrogate outcomes require validation to ensure that they provide sufficient quality of evidence on intervention effects. We review methods that have been proposed over the past 15 years for such validation. The two main approaches are those based on the Prentice criterion, which require data from a single study, and those based on meta-analysis, which require data from many studies. The former approach has fallen out of favor, for reasons to be explained. The latter approach is more popular, but so demanding of resources that it may prove impractical for cancer chemoprevention in all but a few instances. Researchers may have to resign themselves to more limited use of surrogate outcomes, not as replacements for traditional outcomes, but as outcomes for Phase II studies designed to decide which interventions to pass for Phase III testing.

Reduced repair of the oxidative 8-oxoguanine DNA damage and risk of head and neck cancer

An increasing number of studies indicate that reduced DNA-repair capacity is associated with increased cancer risk. Using a functional assay for the removal of the oxidative DNA lesion 8-oxoguanine by the DNA-repair enzyme 8-oxoguanine DNA glycosylase 1 (OGG1), we have previously shown that reduced OGG activity is a risk factor in lung cancer. Here, we report that OGG activity in peripheral blood mononuclear cells from 37 cases with squamous cell carcinoma of the head and neck (SCCHN) was significantly lower than in 93 control subjects, frequency matched for age and gender. Retesting of OGG activity 3 to 4 years after diagnosis and successful treatment of 18 individuals who recovered from the disease showed that OGG activity values were similar to those determined at diagnosis, suggesting that reduced OGG activity in case patients was not caused by the disease. Logistic regression analysis indicated that the adjusted odds ratio (OR) associated with a unit decrease in OGG activity was statistically significantly increased [OR, 2.3; 95% confidence interval (95% CI), 1.5-3.4]. Individuals in the lowest tertile of OGG activity exhibited an increased risk of SCCHN with an OR of 7.0 (95% CI, 2.0-24.5). The combination of smoking and low OGG was associated with a highly increased estimated relative risk for SCCHN. These results suggest that low OGG is associated with the risk of SCCHN, and if confirmed by additional epidemiologic studies, screening of smokers for low OGG activity might be used as a strategy for the prevention of lung cancer and SCCHN.