Vaccins de voyage : quel horizon ? [Travel vaccines: what is in the pipeline?]

While no vaccine is on the horizon to prevent traveler's diarrhea, progress has been made in the field of malaria and dengue fever. In both cases, the objective is not primarily the prevention among travelers but rather the reduction of morbidity and mortality in populations living in endemic areas. The immune mechanisms protecting against parasitosis are not well understood, which further complicates vaccine development. The fact that veterinary vaccines against the parasites causing cysticercosis and echinococcosis are available for animals, justifies a certain optimism that vaccines against parasitosis will also be available for humans in the future. We report on recent developments in dengue, malaria, schistosomiasis, and hookworm vaccines

Diagnostic du Covid-19 en milieu ambulatoire [COVID-19 Diagnosis]

The need to curb the circulation of SARS-CoV-2 virus in the community and to diagnose those at risk of developing complications implies that an appropriate test should be chosen according to the epidemiological and clinical context. Rapid antigen tests, either nasopharyngeal or nasal, have the advantage of reflecting contagiousness better than PCR and giving an immediate result, reason why they are used as first-line for community diagnosis and screening. A rapid test allows immediate management of outpatients and does not falsely attribute the current acute episode to a previous SARS-CoV-2 infection. PCR, whether nasopharyngeal or buccosalivary, is useful for epidemiological surveillance, including that of new variants, as well as identification of severe COVID in the post-infectious phase

Safety and immunogenicity of a synthetic nanoparticle-based, T cell priming peptide vaccine against dengue in healthy adults in Switzerland: a double-blind, randomized, vehicle-controlled, phase 1 study.

Vaccines that minimize the risk of vaccine-induced antibody-dependent enhancement and severe dengue are needed to address the global health threat posed by dengue. This study assessed the safety and immunogenicity of a gold nanoparticle (GNP)-based, multi-valent, synthetic peptide dengue vaccine candidate (PepGNP-Dengue), designed to provide protective CD8+ T cell immunity, without inducing antibodies. In this randomized, double-blind, vehicle-controlled, phase 1 trial (NCT04935801), healthy naïve individuals aged 18-45 years recruited at the Centre for primary care and public health, Lausanne, Switzerland, were randomly assigned to receive PepGNP-Dengue or comparator (GNP without peptides [vehicle-GNP]). Randomization was stratified into four groups (low dose [LD] and high dose [HD]), allocation was double-blind from participants and investigators. Two doses were administered by intradermal microneedle injection 21 days apart. Primary outcome was safety, secondary outcome immunogenicity. Analysis was by intention-to-treat for safety, intention-to-treat and per protocol for immunogenicity. 26 participants were enrolled (August-September 2021) to receive PepGNP-Dengue (LD or HD, n = 10 each) or vehicle-GNP (LD or HD, n = 3 each). No vaccine-related serious adverse events occurred. Most (90%) related adverse events were mild; injection site pain and transient discoloration were most frequently reported. Injection site erythema occurred in 58% of participants. As expected, PepGNP-Dengue did not elicit anti-DENV antibodies of significance. Significant increases were observed in specific CD8+ T cells and dengue dextramer+ memory cell subsets in the LD PepGNP-Dengue but not in the HD PepGNP-Dengue or vehicle-GNP groups, specifically PepGNP-activated CD137+CD69+CD8+ T cells (day 90, +0.0318%, 95% CI: 0.0088-0.1723, p = 0.046), differentiated effector memory (TemRA) and central memory (Tcm) CD8+ T cells (day 35, +0.8/10 <sup>5</sup> CD8+, 95% CI: 0.19-5.13, p = 0.014 and +1.34/10 <sup>5</sup> CD8+, 95% CI: 0.1-7.34, p = 0.024, respectively). Results provide proof of concept that a synthetic nanoparticle-based peptide vaccine can successfully induce virus-specific CD8+ T cells. The favourable safety profile and cellular responses observed support further development of PepGNP-Dengue. Emergex Vaccines Holding Limited

Séjours prolongés en zone endémique de malaria : quelles stratégies de prévention ? [Long-term travelers to malaria endemic areas : What prevention strategies ?]

Long-term travelers are particularly exposed to malaria. It is essential to inform them about this risk, the recognition of the symptoms of the disease and the need for prompt treatment. Addressing any fears of travelers and answering their questions improve therapeutic adherence. Personal protective measures (repellents, mosquito nets) are fundamental and safe to reduce exposure to the vector of the disease. Depending on the individual risk of malaria and the special vulnerability of the traveler, short-term or prolonged chemoprophylaxis and/or emergency self-treatment and a rapid diagnostic test for malaria may be offered

Vaccins à ARN messager contre le Covid-19 : piqûre de rappel [mRNA Covid vaccines: What do we know eight months after deployment]

This paper summarizes the main knowledge on mRNA vaccines in September 2021. The only contraindication for a 1st dose of vaccine is an allergy to one of the components of the vaccine, but a specialized consultation is possible for an eventual split vaccination under medical supervision. Serious side effects are rare and consist mainly of myocarditis, shingles and appendicitis, but the risk/benefit ratio is always favorable for vaccination. Efficacy against severe COVID-19 is > 90 % after 6 months, and this against all variants. It is recommended to vaccinate pregnant women. A 3rd dose is not recommended at this time, except for immunosuppressed individuals without detectable antibodies after 2 doses. Vaccine mixing is possible, including with a viral vector vaccine

Adolescents porteurs d'affections chroniques : la parole aux patients = [Adolescents with chronic condition: what do they have to tell]

Contexte : Un adolescent sur dix environ souffre d'une affection chronique; le vécu d'une telle situation reste relativement ignoré des soignants. Objectifs : A l'aide d'un focus groupe avec des adolescents porteurs d'une affection chronique (AC) explorer les représentations par rapport au soutien et à l'adaptation à l'AC et la perception de la prise en charge par les équipes soignantes. Résultats : Douze garçons et filles de 12 à 18 ans de la Suisse romande ont participé à une discussion semi-directive de deux heures et rapportent que c'est surtout sur eux-mêmes qu'ils doivent compter avant de se tourner vers leurs parents ou leurs amis. Les pairs, l'équipe soignante, les autres malades et les enseignants ont chacun des rôles importants à jouer à des moments ou un autre de l'évolution de l'AC. Ces jeunes demandent aux médecins une prise en charge globale plutôt que focalisée seulement sur leur AC. Le respect, la possibilité d'un soutien et d'explications précises leur paraissent importants. Conclusion : Les médecins et équipes soignantes doivent anticiper les questions difficiles à poser, permettre à leurs jeunes patients de nommer leurs émotions et de développer une vision positive de leur avenir en favorisant leur autonomisation et leur intégration dans la société

Voyager écolo : quelles recommandations ? [Eco-tourism: what recommendations?]

Which recommendations family doctors and travel health practitioners can provide to their patients, to reduce their environmental footprint when travelling? Avoiding flying is the biggest action a traveler can take to reduce their greenhouse gas emissions. Staying at eco-lodges, or carbon offsetting, may help, but one must be aware of false or exaggerated claims on their impact. Using UV light, filters, halogens or boiling water, are effective ways to disinfect water and reduce the waste created from plastic water bottles. Given the large carbon footprint of medications and laboratory exams, limiting prescription of antibiotics or antimalarials in pre-travel consultations, or limiting unnecessary laboratory exams in returning travelers by following the latest recommendations, could reduce greenhouse emissions of the medical practice

COVID-19 Vaccination Program for Undocumented Migrants: Notes from the Field of a Regional Center of General Medicine and Public Health, Canton of Vaud, Switzerland.

The COVID-19 pandemic highlighted health inequities for vulnerable populations and the need for more equitable care and access to vaccination. This article described the implementation of a COVID-19 vaccination program for undocumented migrants in a regional academic center of general medicine and public health (Unisanté). The vaccination program's specific components included: triple coordination between the health authorities, the regional center and community partners, a walk-in and free service, no health insurance required, qualified nursing and administrative staff with previous experience with vulnerable populations, translated information materials and interpreters, a guarantee of confidentiality and a widespread communication campaign within the communities. In total, 2'351 undocumented migrants from 97 nationalities received at least one dose of mRNA COVID-19 vaccine (Spikevax) and 2242 were considered fully vaccinated. Although it was hard to assess its global effectiveness, the program vaccinated a significant number of undocumented adult migrants in the Canton of Vaud. The difficulties linked to the pandemic context, the heavy workload for healthcare staff and the limited resources were overcome by strong collaborations between the different actors involved throughout the program. Targeted public health policies, such as vaccination programs for undocumented migrants, are essential to guarantee equitable care, especially in pandemic times

Revaccination of persons with an immediate reaction after the first dose of mRNA COVID-19 vaccine

Background: The newly developed mRNA-based COVID-19 vaccines can provoke anaphylaxis. Management of persons with an immediate reaction suggestive of an allergy after the first dose remains to be defined. The newly developed mRNA-based COVID-19 vaccines can provoke anaphylaxis. Management of persons with an immediate reaction suggestive of an allergy after the first dose remains to be defined. Method: Skin testing was performed with both mRNA-based vaccines. Upon a negative skin test, a 2-step (10 + 90%) revaccination protocol was performed. Positive skin tests were confirmed with a Basophil Activation Test (BAT). Results: 25'162 first doses of COVID-19 vaccines (80% from Pfizer BioNTech) were administered at the university hospital of Lausanne. Respectively, 3.47 and 1.99 immediate reactions per 10'000 doses were observed with the vaccine of Pfizer BioNTech and Moderna. An allergy workup was performed in 18 persons among who 11 were referred from external centers. 17/18 (94%) were females and 7/18 (39%) had criteria for anaphylaxis. 3/18 (17%), 2/3 with anaphylaxis, had positive intradermal reactivity after 20 minutes for both mRNA vaccines. BAT was positive in 2 persons and is pending in the third one. 14 patients had negative skin testing. Among those 8 received a 2-step re-vaccination protocol, 3 refused revaccination, and 3 wait for revaccination. 8/8 with negative tests tolerated the 2-step re-vaccination. One patient with suspicious skin tests but positive BAT developed again urticaria 7 minutes after the 90% dose. Conclusion: Only 22% of patients, all females, with an immediate reaction to the first vaccination were sensitized to the vaccine. A two-step re-vaccination protocol could be safely administered upon negative skin testing