Analysis of COVID-19 Risk Following a Ring Vaccination Intervention to Address SARS-CoV-2 Alpha Variant Transmission in Montreal, Canada.

Importance: Given limited COVID-19 vaccine availability early in the pandemic, optimizing immunization strategies was of paramount importance. Ring vaccination has been used successfully to control transmission of other airborne respiratory viruses. Objective: To assess the association of a ring vaccination intervention on COVID-19 spread in the initial epicenter of SARS-CoV-2 Alpha variant transmission in Montreal, Canada. Design, Setting, and Participants: This cohort study compared COVID-19 daily disease risk in 3 population-based groups of neighborhoods in Montreal, Canada, defined by their intervention-specific vaccine coverage at the neighborhood level: the primary intervention group (500 or more vaccinated persons per 10 000 persons), secondary intervention group (95 to 499), and control group (0 to 50). The groups were compared within each of 3 time periods: before intervention (December 1, 2020, to March 16, 2021), during and immediately after intervention (March 17 to April 17, 2021), and 3 weeks after the intervention midpoint (April 18 to July 18, 2021). Data were analyzed between June 2021 and November 2021. Exposures: Vaccination targeted parents and teachers of children attending the 32 schools and 48 childcare centers in 2 adjacent neighborhoods with highest local transmission (case counts) of Alpha variant shortly after its introduction. Participants were invited to receive 1 dose of mRNA vaccine between March 22 and April 9, 2021 (before vaccine was available to these age groups). Main Outcomes and Measures: COVID-19 risk in 3 groups of neighborhoods based on intervention-specific vaccine coverage. Results: A total of 11 794 residents were immunized, with a mean (SD) age of 43 (8) years (range, 16-93 years); 5766 participants (48.9%) lived in a targeted neighborhood, and 9784 (83.0%) were parents. COVID-19 risk in the primary intervention group was significantly higher than in the control group before (unadjusted risk ratio [RR], 1.58; 95% CI 1.52-1.65) and during (RR, 1.63; 95% CI, 1.52-1.76) intervention, and reached a level similar to the other groups in the weeks following the intervention (RR, 1.03; 95% CI, 0.94-1.12). A similar trend was observed when restricting to SARS-CoV-2 variants and persons aged 30 to 59 years (before: RR, 1.72; 95% CI, 1.63-1.83 vs after: RR, 1.01; 95% CI, 0.88-1.17). Conclusions and Relevance: Our findings show that ring vaccination was associated with a reduction in COVID-19 risk in areas with high local transmission of Alpha variant shortly after its introduction. Ring vaccination may be considered as an adjunct to mass immunization to control transmission in specific areas, based on local epidemiology.

Making sense of what exactly public health does: a typology of public health interventions.

SETTING: Montréal. INTERVENTION: The lack of common knowledge about what public health does is a hindrance to its recognition and capacity to act. Montréal's regional public health department set an explicit goal to clarify and better communicate its specific contributions when it developed its 2016-2021 action plan. This article briefly describes the efforts made to classify public health practice, introduces a typology of public health interventions and discusses its application and benefits. OUTCOMES: The typology that was developed defines 29 types of interventions grouped into four categories: direct action targeting the population; advocacy (persuading partners to take action); support (helping partners take action); collaboration (taking action with partners). The analysis of Montreal's most recent action plan, completely drafted in terms of the typology, provides an insightful characterization of public health practice. Globally, four out of five interventions target partners (indirect), with more than half falling within the support category. Other indirect interventions are divided almost equally between advocacy and collaboration. Following a rigorous planning process and enforcing the use of the typology also had a significant structuring effect on the organization and its teams and enabled greater synergy with partners from other sectors. IMPLICATIONS: Very few people are familiar with everything public health does, sometimes not even the responsible political decision-makers. This situation poses a threat to the survival of its prevention mission. The typology of public health interventions is an innovative tool that can be used to better inform the public and decision-makers.

Seeing is believing: an educational outreach activity on disinfection practices.

BACKGROUND: Skin and soft-tissue infections are very common among persons who inject drugs. They occur when microbes pass under the protective layer of the skin and proliferate. This happens when harm reduction recommendations such as skin aseptia before injection and sterile injection equipment usage are not properly followed. METHODS: A group of active drug users involved in a health promotion project as peer educators were asked about their formation needs. To address their inquiries concerning skin and soft-tissue infections, we devised with them a series of workshops touching upon common infections, the microflora, and microbial transmission. RESULTS: Participants learned to identify common infections and how to properly react in case of an abscess, cellulitis or phlebitis. They saw microscopic objects, found out about the high prevalence of microbes in their environment and on their skin, and could appreciate the efficiency of different washing and disinfection techniques. They visualized how easily microbes can spread from person to person and from contaminated objects to persons. CONCLUSION: In the weeks following this activity, some participants demonstrated and reported healthy behavioural changes regarding their own injection practices. Furthermore, they shared their newfound knowledge and began enforcing its application among people they inject drugs with. Most participants greatly appreciated this activity and valued it as being highly efficient and tangible. Note: A French version of this paper is available on the Journal's web site [see Additional file 1].

[The critical reading of scientific articles, an easy-to-use method]. / La lecture critique d'articles scientifiques, une méthode simple a utiliser.

Faced with the abundance of available literature, clinicians must follow a method in order to carry out a critical reading of scientific articles. This enables them to decide how relevant the selected article is to the issues specific to their area of work and to choose whether to undertake a basic critical reading or to embark on an active reading.