1. FDA proposes once-a-year covid vaccine shots for most Americans. CBS News. 23 Jan 2023. https://www.cbsnews.com/news/fda-covid-shots-yearly-for-most-americans/
2. Centers for Disease Control and Prevention. Covid-19 vaccinations in the United States. https://covid.cdc.gov/covid-data-tracker/#vaccinations_vacc-people-booster-percent-pop5
3. Covid-19: China stops counting cases as models predict a million or more deaths
4. WHO urges China to step up vaccinations after rise in covid cases. Financial Times 2022 Dec 21. https://www.ft.com/content/4fead016-b654-4d08-a9dd-70b25058023a (Login needed)
5. Covid-19: Winter surge feared as China lurches away from zero covid