https://www.mercurynews.com/2021/08/18/new-data-shows-waning-covid-19-vaccine-efficacy-building-case-for-boosters/ > COVID-19 vaccines are losing their effectiveness against infection over time and might become less protective in preventing severe illness and death, the nation’s top health officials said Wednesday. > These new medical findings, announced at a White House press briefing, are spurring the campaign to boost Americans’ immunity by administering a third dose of the vaccine.