1. Department of Health and Social Care. All adults to be offered covid-19 boosters by end of January—almost 7 million extra over 40s now eligible for booster programme in England as gap between doses is halved. Nov 2021. https://www.gov.uk/government/news/all-adults-to-be-offered-covid-19-boosters-by-end-of-january.
2. Centers for Disease Control and Prevention. Interim clinical considerations for use of covid-19 vaccines currently approved or authorized in the United States. https://www.cdc.gov/vaccines/covid-19/clinical-considerations/covid-19-vaccines-us.html.
3. Covid-19: 40% of patients with weakened immune system mount lower response to vaccines
4. New study tests third jab for people with weakened immune systems. UK Research and Innovation. Aug 2021. https://www.ukri.org/news/new-study-tests-third-jab-for-people-with-weakened-immune-systems.
5. Prime Minister’s Office. PM Bennett announces Israelis 60+ and medical workers to receive 4th vaccine. Jan 2022. https://www.gov.il/en/departments/news/event_statement020122.