<p><strong>Source:</strong> 1. Healthdirect.gov.au Coronavirus (COVID-19) Symptom Checker (v0.1) Department of Health, Australia. Available at <a href="https://www.health.gov.au/health-topics/flu-influenza" target="_blank">https://www.health.gov.au/<wbr/>health-topics/flu-influenza</a> 2. Australian Technical Advisory Group on Immunisation (ATAGI) Advice on the relative timing of administering influenza and COVID-19 vaccines in 2021 - covid-19-vaccination-atagi-advice-on-influenza-and-covid-19-vaccines (v1.0).</p>