METHODS: The candidate vaccines' pharmaceutical parameters (e.g. platforms, number needed to vaccinate and intervals, adjuvanted status, excipients and preservatives added, efficacy and effectiveness, vaccine adverse events, and boosters), and clinical aspects must be analysed for the mix-and-match approach. Results prime-boost trials showed safety, effectiveness, higher systemic reactogenicity, well tolerability with improved immunogenicity, and flexibility profiles for future vaccinations, especially during acute and global shortages, compared to the homologous counterparts.
CONCLUSION: Still, large controlled trials are warranted to address challenging variants of concerns including Omicron and other, and to generalize the effectiveness of the approach in regular as well as emergency use during vaccine scarcity.
METHODS: Data were collected on travellers evaluated at GeoSentinel Network sites who reported healthcare during travel. Both unplanned and planned healthcare were analysed, including the reason and nature of healthcare sought, characteristics of the treatment provided and outcomes. Travellers that presented for rabies post-exposure prophylaxis were described elsewhere and were excluded from detailed analysis.
RESULTS: From May 2017 through June 2020, after excluding travellers obtaining rabies post-exposure prophylaxis (n= 415), 1093 travellers reported care for a medical or dental issue that was an unanticipated part of the travellers' planned itinerary (unplanned healthcare). Travellers who sought unplanned healthcare abroad had frequent diagnoses of acute diarrhoea, dengue, falciparum malaria and unspecified viral syndrome, and obtained care in 131 countries. Thirty-four (3%) reported subsequent deterioration and 230 (21%) reported no change in condition; a third (n = 405; 37%) had a pre-travel health encounter. Forty-one travellers had sufficient data on planned healthcare abroad for analysis. The most common destinations were the US, France, Dominican Republic, Belgium and Mexico. The top reasons for their planned healthcare abroad were unavailability of procedure at home (n = 9; 19%), expertise abroad (n = 9; 19%), lower cost (n = 8; 17%) and convenience (n = 7; 15%); a third (n = 13; 32%) reported cosmetic or surgical procedures. Early and late complications occurred in 14 (33%) and 4 (10%) travellers, respectively. Four travellers (10%) had a pre-travel health encounter.
CONCLUSIONS: International travellers encounter health problems during travel that often could be prevented by pre-travel consultation. Travellers obtaining planned healthcare abroad can experience negative health consequences associated with treatments abroad, for which pre-travel consultations could provide advice and potentially help to prevent complications.