Hybrid immunity from SARS-CoV-2 infection and vaccination in Canadian adults: cohort study.

Background: Few national-level studies have evaluated the impact of 'hybrid' immunity (vaccination coupled with recovery from infection) from the Omicron variants of SARS-CoV-2.Methods: From May 2020 to December 2022, we conducted serial assessments (each of ~4000-9000 adults) examining SARS-CoV-2 antibodies within a mostly representative Canadian cohort drawn from a national online polling platform. Adults, most of whom were vaccinated, reported viral test-confirmed infections and mailed self-collected dried blood spots to a central lab. Samples underwent highly sensitive and specific antibody assays to spike and nucleocapsid protein antigens, the latter triggered only by infection. We estimated cumulative SARS-CoV-2 incidence prior to the Omicron period and during the BA.1/1.1 and BA.2/5 waves. We assessed changes in antibody levels and in age-specific active immunity levels.Results: Spike levels were higher in infected than in uninfected adults, regardless of vaccination doses. Among adults vaccinated at least thrice and infected more than six months earlier, spike levels fell notably and continuously for the nine months post-vaccination. By contrast, among adults infected within six months, spike levels declined gradually. Declines were similar by sex, age group, and ethnicity. Recent vaccination attenuated declines in spike levels from older infections. In a convenience sample, spike antibody and cellular responses were correlated. Near the end of 2022, about 35% of adults above age 60 had their last vaccine dose more than six months ago, and about 25% remained uninfected. The cumulative incidence of SARS-CoV-2 infection rose from 13% (95% CI 11-14%) before omicron to 78% (76-80%) by December 2022, equating to 25 million infected adults cumulatively. However, the COVID-19 weekly death rate during the BA.2/5 waves was less than half of that during the BA.1/1.1 wave, implying a protective role for hybrid immunity.Conclusions: Strategies to maintain population-level hybrid immunity require up-to-date vaccination coverage, including among those recovering from infection. Population-based, self-collected dried blood spots are a practicable biological surveillance platform.Funding: Funding was provided by the COVID-19 Immunity Task Force, Canadian Institutes of Health Research, Pfizer Global Medical Grants, and St. Michael's Hospital Foundation. PJ and ACG are funded by the Canada Research Chairs Program.

Cobalt-Catalyzed Enantioselective Reductive Amination of Ketones with Hydrazides.

An efficient cobalt-catalyzed asymmetric reductive amination of ketones with hydrazides has been realized, directly producing valuable chiral hydrazines in high yields and enantioselectivities (up to 98% enantiomeric excess).

Assessment of SARS-CoV-2 Seropositivity During the First and Second Viral Waves in 2020 and 2021 Among Canadian Adults.

Importance: The incidence of infection during SARS-CoV-2 viral waves, the factors associated with infection, and the durability of antibody responses to infection among Canadian adults remain undocumented. Objective: To assess the cumulative incidence of SARS-CoV-2 infection during the first 2 viral waves in Canada by measuring seropositivity among adults. Design, Setting, and Participants: The Action to Beat Coronavirus study conducted 2 rounds of an online survey about COVID-19 experience and analyzed immunoglobulin G levels based on participant-collected dried blood spots (DBS) to assess the cumulative incidence of SARS-CoV-2 infection during the first and second viral waves in Canada. A sample of 19 994 Canadian adults (aged ≥18 years) was recruited from established members of the Angus Reid Forum, a public polling organization. The study comprised 2 phases (phase 1 from May 1 to September 30, 2020, and phase 2 from December 1, 2020, to March 31, 2021) that generally corresponded to the first (April 1 to July 31, 2020) and second (October 1, 2020, to March 1, 2021) viral waves. Main Outcomes and Measures: SARS-CoV-2 immunoglobulin G seropositivity (using a chemiluminescence assay) by major geographic and demographic variables and correlation with COVID-19 symptom reporting. Results: Among 19 994 adults who completed the online questionnaire in phase 1, the mean (SD) age was 50.9 (15.4) years, and 10 522 participants (51.9%) were female; 2948 participants (14.5%) had self-identified racial and ethnic minority group status, and 1578 participants (8.2%) were self-identified Indigenous Canadians. Among participants in phase 1, 8967 had DBS testing. In phase 2, 14 621 adults completed online questionnaires, and 7102 of those had DBS testing. Of 19 994 adults who completed the online survey in phase 1, fewer had an educational level of some college or less (4747 individuals [33.1%]) compared with the general population in Canada (45.0%). Survey respondents were otherwise representative of the general population, including in prevalence of known risk factors associated with SARS-CoV-2 infection. The cumulative incidence of SARS-CoV-2 infection among unvaccinated adults increased from 1.9% in phase 1 to 6.5% in phase 2. The seropositivity pattern was demographically and geographically heterogeneous during phase 1 but more homogeneous by phase 2 (with a cumulative incidence ranging from 6.4% to 7.0% in most regions). The exception was the Atlantic region, in which cumulative incidence reached only 3.3% (odds ratio [OR] vs Ontario, 0.46; 95% CI, 0.21-1.02). A total of 47 of 188 adults (25.3%) reporting COVID-19 symptoms during phase 2 were seropositive, and the OR of seropositivity for COVID-19 symptoms was 6.15 (95% CI, 2.02-18.69). In phase 2, 94 of 444 seropositive adults (22.2%) reported having no symptoms. Of 134 seropositive adults in phase 1 who were retested in phase 2, 111 individuals (81.8%) remained seropositive. Participants who had a history of diabetes (OR, 0.58; 95% CI, 0.38-0.90) had lower odds of having detectable antibodies in phase 2. Conclusions and Relevance: The Action to Beat Coronavirus study found that the incidence of SARS-CoV-2 infection in Canada was modest until March 2021, and this incidence was lower than the levels of population immunity required to substantially reduce transmission of the virus. Ongoing vaccination efforts remain central to reducing viral transmission and mortality. Assessment of future infection-induced and vaccine-induced immunity is practicable through the use of serial online surveys and participant-collected DBS.

COVID-19 vaccination intention during early vaccine rollout in Canada: a nationwide online survey.

BACKGROUND: Understanding vaccination intention during early vaccination rollout in Canada can help the government's efforts in vaccination education and outreach. METHOD: Panel members age 18 and over from the nationally representative Angus Reid Forum were invited to complete an online survey about their experience with COVID-19, including their intention to get vaccinated. Respondents were asked "When a vaccine against the coronavirus becomes available to you, will you get vaccinated or not?" Having no intention to vaccinate was defined as choosing "No - I will not get a coronavirus vaccination" as a response. Odds ratios and predicted probabilities are reported for no vaccine intentionality in demographic groups. FINDINGS: 14,621 panel members completed the survey. Having no intention to vaccinate against COVID-19 is relatively low overall (9%) with substantial variation among demographic groups. Being a resident of Alberta (predicted probability = 15%; OR 0.58 [95%CI 0.14-2.24]), aged 40-59 (predicted probability = 12%; OR 0.87 [0.78-0.97]), identifying as a visible minority (predicted probability = 15%; OR 0.56 [0.37-0.84]), having some college level education or lower (predicted probability = 14%) and living in households of at least five members (predicted probability = 13%; OR 0.82 [0.76-0.88]) are related to lower vaccination intention. INTERPRETATION: The study identifies population groups with greater and lesser intention to vaccinate in Canada. As the Canadian COVID-19 vaccination effort continues, policymakers may use this information to focus outreach, education, and other efforts on the latter groups, which also have had higher risks for contracting and dying from COVID-19. FUNDING: Pfizer Global Medical, Unity Health Foundation, Canadian COVID-19 Immunity Task Force.

Food Security Status among U.S. Older Adults: Functional Limitations Matter.

This study aimed to assess the relationship between food security and health outcomes among older adults (age 65+) in the U.S. We used a pooled sample (2011-2015, N = 37,292) from the National Health Interview Survey (NHIS) and ordered logit models to assess characteristics associated with food security including health conditions (diabetes and hypertension) and functional activity limitations. We estimated that 1.3 million individuals aged 65+ in the U.S. had low/very low food security. Having at least one functional limitation (OR = 1.717, 95% CI = 1.436, 2.054) was significantly associated with low/very low food security. Having fair or poor health status (OR = 3.315, 95% CI = 2.938, 3.739) was also a significant factor for food security among older adults, while having health insurance coverage (OR = 0.467, 95% CI = 0.341, 0.64) was negatively associated with food insecurity. Demographics and socioeconomic characteristics were significantly related to food insecurity among seniors. Seniors with functional limitations and poor health status are at risk for food insecurity. Interventions at the clinical site of care may be useful in addressing food security issues for older adults.

The effect of a fresh produce incentive paired with cooking and nutrition education on healthy eating in low-income households: a pilot study.

OBJECTIVE: This study pilot-tested combining financial incentives to purchase fruits and vegetables with nutrition education focused on cooking to increase the consumption of fruits and vegetables and improve attitudes around healthy eating on a budget among low-income adults. The goal of the pilot study was to examine implementation feasibility and fidelity, acceptability of the intervention components by participants and effectiveness. DESIGN: The study design was a pre-post individual-level comparison without a control group. The pilot intervention included two components, a scan card providing free produce up to a weekly maximum dollar amount for use over a 2-month period, and two sessions of tailored nutrition and cooking education. Outcomes included self-reported attitudes about healthy eating and daily fruit and vegetable consumption from one 24-h dietary recall collected before and after the intervention. SETTING: Greater Minneapolis/St. Paul area in Minnesota. PARTICIPANTS: Adults (n 120) were recruited from five community food pantries. RESULTS: Findings indicated that the financial incentive component of the intervention was highly feasible and acceptable to participants, but attendance at the nutrition education sessions was moderate. Participants had a statistically significant increase in the consumption of fruit, from an average of 1·00 cup/d to 1·78 cups/d (P < 0·001), but no significant change in vegetable consumption or attitudes with respect to their ability to put together a healthy meal. CONCLUSIONS: While combining financial incentives with nutrition education appears to be acceptable to low-income adult participants, barriers to attend nutrition education sessions need to be addressed in future research.

Eating behavior and weight gain during pregnancy.

OBJECTIVES: Little is known about the relationship between eating behavior and weight gain during pregnancy. PURPOSE: Our objective was to assess the relationship among self-reported cognitive restraint, disinhibition, and hunger, and excessive gestational weight gain (GWG) as defined by the Institute of Medicine's (IOM) 2009 guidelines. Based on previous research examining eating behaviors and weight gain in non-pregnant women, we hypothesized that excessive GWG would be related to higher cognitive restraint, higher disinhibition, and higher perception of hunger. METHODS: 190 pregnant women from the Glowing study completed the Three-Factor Eating Questionnaire (TFEQ) at the enrollment visit, which included subscales assessing restraint, disinhibition, and hunger. Participants' height and weight from <10 weeks through 36 weeks gestation were measured, allowing classification within or in excess of the IOM guidelines adjusted for the week of the final measurement. RESULTS: The odds that a participant would gain weight above IOM recommendations was 1.2 times higher (OR = 1.17, 95% CI = 1.05-1.29) for each one-unit increase in the disinhibition subscale in the unadjusted logistic regression. However, after controlling for sociodemographic characteristics and baseline BMI categories, participants' TFEQ scores were not associated with the likelihood of having GWG above IOM guidelines. Eating behaviors subscales were modestly correlated with baseline BMI categories (all rs < 0.50 with p-values ranging from <0.001 to 0.619). CONCLUSIONS: Although disinhibition scores had a significant relationship with excessive GWG, the significance of this relationship was not sustained after adjusting for sociodemographic characteristics and baseline BMI categories.

Preliminary evaluation of the Healthy Savings Program: a novel health insurance-based wellness programme to encourage healthy food purchases.

OBJECTIVE: To examine level of participation and satisfaction with the Healthy Savings Program (HSP), a programme that provides price discounts on healthier foods. DESIGN: For Study 1, a survey was distributed to a random sample of adults who were invited to participate in a version of the HSP that provided a discount for the purchase of fresh produce and discounts on other healthier foods. In Study 2, interviews were conducted with a convenience sample of adults invited to participate in a version of the HSP that provided price discounts on specific products only (no fresh produce discount). SETTING: The HSP is provided to all employer-based insurance plan members of a large health plan. Employers can choose to enhance the version of the HSP that their employees receive by paying for a weekly discount on fresh produce. SUBJECTS: Employees in employer groups that received the enhanced HSP (Study 1) and employees in an employer group (Study 2) that received the standard HSP. RESULTS: Among survey respondents in Study 1, 69·3 % reported using the HSP card. Most were satisfied with the fresh produce discount and ease of use of the HSP card. Satisfaction was lower for selection of participating stores, amounts of discounts and selection of discounted products. In Study 2, barriers to the use of the HSP card cited included the limited number of participating stores and the limited selection of discounted products. CONCLUSIONS: Satisfaction with some elements of the HSP was high while other elements may need improvement to increase programme use.

The effect of proportional v. value pricing on fountain drink purchases: results from a field experiment.

OBJECTIVE: Reducing sugar-sweetened beverage consumption is a public health priority, yet finding an effective and acceptable policy intervention is challenging. One strategy is to use proportional pricing (a consistent price per fluid ounce) instead of the typical value-priced approach where large beverages offer better value. The purpose of the present study was to evaluate whether proportional pricing affects the purchasing of fountain beverages at a university cinema concession stand. DESIGN: Four price strategies for beverages were evaluated over ten weekends of film screenings. We manipulated two factors: the price structure (value pricing v. proportional pricing) and the provision of information about the price per fluid ounce (labels v. no labels). The key outcomes were the number and size of beverages purchased. We analysed data using regression analyses, with standard errors clustered by film and controlling for the day and time of purchase. SETTING: A university cinema concession stand in Minnesota, USA, in spring 2015. SUBJECTS: University students. RESULTS: Over the study period (360 beverages purchased) there were no significant effects of the proportional pricing treatment. Pairing a label with the standard value pricing increased the likelihood of purchasing large drinks but the label did not affect purchasing when paired with proportional pricing. CONCLUSIONS: Proportional prices did not significantly affect the size of beverages purchased by students at a university cinema, but adding a price-per-ounce label increased large drink purchases when drinks were value-priced. More work is needed to address whether pricing and labelling strategies might promote healthier beverage purchases.

Young adults' responses to alternative messages describing a sugar-sweetened beverage price increase.

OBJECTIVE: Many jurisdictions in the USA and globally are considering raising the prices of sugar-sweetened beverages (SSB) through taxes as a strategy to reduce their consumption. The objective of the present study was to identify whether the rationale provided for an SSB price increase affects young adults' behavioural intentions and attitudes towards SSB. DESIGN: Participants were randomly assigned to receive one of eight SSB price increase rationales. Intentions to purchase SSB and attitudes about the product and policy were measured. SETTING: A forty-six-item cross-sectional Internet survey. SUBJECTS: Undergraduate students (n 494) at a large US Midwestern university. RESULTS: Rationale type was significantly associated with differences in participants' purchasing intentions for the full sample (F 7,485=2·53, P=0·014). Presenting the rationale for an SSB price increase as a user fee, an effort to reduce obesity, a strategy to offset health-care costs or to protect children led to lower SSB purchasing intentions compared with a message with no rationale. Rationale type was also significantly associated with differences in perceptions of soda companies (F 7,485=2·10, P=0·043); among low consumers of SSB, messages describing the price increase as a user fee or tax led to more negative perceptions of soda companies. CONCLUSIONS: The rationale attached to an SSB price increase could influence consumers. However, these message effects may depend on individuals' level of SSB consumption.

Associations between food environment around schools and professionally measured weight status for middle and high school students.

BACKGROUND: Obesity rates among school-age children remain high. Access to energy-dense foods at home, in schools, in stores, and restaurants around homes and schools is of concern. Research on the relationship between food environment around schools and students' weight status is inconclusive. This study examines the association between weight status of middle and high school students and proximity to a comprehensive set of food outlets around schools. METHODS: Deidentified nurse-measured heights and weights data were obtained for 12,954 middle and high school students attending 33 public schools in four low-income communities in New Jersey. Geocoded locations of supermarkets, convenience stores, small grocery stores, and limited-service restaurants were obtained from commercial sources. Random-effect regression models with robust standard errors were developed to adjust for unequal variances across schools and clustering of students within schools. RESULTS: Proximity to small grocery stores that offered some healthy options (e.g., five fruits, five vegetables, and low-fat/skim milk) and supermarkets was associated with healthier student weight status. Having a small grocery store within 0.25 mile of school and an additional such store within that radius was associated with a lower BMI z-score (p<0.05). An additional supermarket within 0.25 mile of schools was associated with a lower probability of being overweight/obese (p<0.05). CONCLUSIONS: Improving access to healthy food outlets, such as small stores, that offer healthy food options and supermarkets around middle and high schools is a potential strategy for improving weight outcomes among students.