Viral Respiratory Epidemic Modeling of Societal Segregation Based on Vaccination Status

BACKGROUND

Societal segregation of unvaccinated people from public spaces has been a novel and controversial coronavirus disease 2019 (COVID-19)-era public health practice in many countries. Models exploring potential consequences of vaccination-status-based segregation have not considered how segregation influences the contact frequencies in the segregated groups. We systematically investigate implementing effects of segregation on population-specific contact frequencies and show this critically determines the predicted epidemiological outcomes, focusing on the attack rates in the vaccinated and unvaccinated populations and the share of infections among vaccinated people that were due to contacts with infectious unvaccinated people.

METHODS

We describe a susceptible-infectious-recovered (SIR) two-population model for vaccinated and unvaccinated groups of individuals that transmit an infectious disease by person-to-person contact. The degree of segregation of the two groups, ranging from zero to complete segregation, is implemented using the like-to-like mixing approach developed for sexually transmitted diseases, adapted for presumed severe acute respiratory syndrome coronavirus 2 (SARS‑CoV‑2) transmission. We allow the contact frequencies for individuals in the two groups to be different and depend, with variable strength, on the degree of segregation.

RESULTS

Segregation can either increase or decrease the attack rate among the vaccinated, depending on the type of segregation (isolating or compounding), and the contagiousness of the disease. For diseases with low contagiousness, segregation can cause an attack rate in the vaccinated, which does not occur without segregation.

INTERPRETATION

There is no predicted blanket epidemiological advantage to segregation, either for the vaccinated or the unvaccinated. Negative epidemiological consequences can occur for both groups.

Social networks and mental health change in older adults after the Covid-19 outbreak

OBJECTIVES

This article examines the influence of social networks on selected aspects of mental health following the outbreak of the coronavirus.

METHOD

We linked data from a post outbreak telephone survey in 2020 by the Survey of Health, Ageing and Retirement in Europe, with baseline data from SHARE Wave 6 (2016) (n = 33,485). Two mental health measures (depression and anxiety) were regressed on social network variables relevant to the Covid-19 crisis (frequency of face-to-face contact and frequency of contact through electronic means), controlling for confounders. Interactions of age group and social networks were considered. Baseline mental health was controlled, focusing the analysis on post-outbreak mental health change.

RESULTS

Face-to-face network contact significantly reduced negative mental health changes while electronic contact significantly increased them. The age interactions were insignificant. Country differences were observed.

CONCLUSION

The findings suggest that face-to-face social networks can moderate the negative impact of the COVID-19 pandemic on important aspects of mental health.

Affiliated stigma and contact frequency in sibling relationships of adults with intellectual disabilities: The mediation of relational motivations

Background: Typically developing (TD) siblings play a crucial role in promoting the health and well-being of adults with intellectual disabilities. Their involvement in the sibling relationship during adulthood may predict their likelihood of providing care to the sibling with intellectual disabilities (ID). However, different types of motivations (discretionary and obligatory) related to the contact frequency of TD siblings have not been fully explored. Little is known about how their negative experiences, such as affiliated stigma, influences relational motivations, which consequently affect contact frequency. This study examined these links in a Chinese context. Method: In total, 1,298 Chinese siblings were surveyed using questionnaires, and structural equation modelling was used to test the mediation effect. Results: Contact frequencies of TD siblings were significantly affected by discretionary motivation, obligatory motivation, and stigma experiences. The findings supported the mediating effect of obligatory motivation in the relationship between affiliated stigma and contact frequency. Conclusion: This study is among the first to examine whether the relational motivation of TD siblings predicts their contact frequency within their relationships with adult siblings with ID. We found that both types of relational motivations of TD siblings positively predicted contact behavior.

The longitudinal association between social network composition and episodic memory in older adulthood: the importance of contact frequency with friends

Objectives: The composition of one's social network has been associated with cognition such that a greater proportion of family is associated with worse cognition compared to a greater proportion of friends. It is not clear whether this association between network composition and cognitive aging is driven by potential negative effects of family interactions or positive effects of friend interactions.Methods: Using the Health and Retirement Study (T1: 2006/2008, T2: 2010/2012, T3: 2012/2014), a longitudinal mediation model was conducted to test the effects of composition on episodic memory and latent change in memory through contact frequency with friends and family.Results: Analyses revealed indirect effects of composition on both T2 memory and latent change in memory through contact frequency with friends. A greater proportion of family in one's network was associated with lower contact frequency with friends and in turn lower memory. Composition was also associated with higher contact frequency with family; however, contact frequency with family was not associated with memory.Conclusions: These findings suggest that spending time with family may not affect episodic memory in older adulthood, but spending time with friends may be beneficial. Potential mechanisms and implications regarding the importance of friendships in later life are discussed.

Intergenerational contacts and depressive symptoms among older parents in Eastern Europe

OBJECTIVE

We investigate the association between parent-child contact frequency and changes in older parents' depressive symptoms in Bulgaria, Georgia and Russia. These are countries in which societal transformations may mean that psychological feelings of security engendered by having children in close contact may have particularly important implications for the mental health of older parents.

METHODS

We analysed data from two waves of the Generation and Gender Surveys conducted three years apart and took account of relationships with more than one child. Analyses were performed using OLS regression models, adjusted for depressive symptoms at baseline.

RESULTS

Among mothers increases in depressive symptoms were greater for those who lacked at least weekly contact with any child than for those with frequent contact with at least one child (b = 0.64; p<0.01). Increases in depressive symptoms were associated with infrequent contacts with children, even after controlling for relationship quality (b = 0.55; p<0.05). Among unpartnered fathers, less than weekly meetings with children were associated with increases in depressive symptoms.

CONCLUSIONS

Among mothers and unpartnered fathers changes in depressive symptoms varied by parent-child contact. The adverse effect of not having a partner on fathers' mental health was reduced, but not eliminated, by having frequent contacts with adult children.