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3. Danish Health Authority. Denmark continues its vaccine rollout without the COVID-19 vaccine from AstraZeneca. Copenhagen: Danish Health Authority; 2021. Available from: https://www.sst.dk/en/English/news/2021/Denmark-continues-its-vaccine-rollout-without-the-COVID-19-vaccine-from-AstraZeneca
4. Public Health Agency of Canada. NACI rapid response: Interchangeability of authorized COVID-19 vaccines. Ottawa: Public Health Agency of Canada; 2021. Available from: https://www.canada.ca/en/public-health/services/immunization/national-advisory-committee-on-immunization-naci/recommendations-use-covid-19-vaccines/rapid-response-interchangeability.html
5. Heterologous prime-boost COVID-19 vaccination: initial reactogenicity data.;Shaw;Lancet,2021