The U.S. Food and Drug Administration, or FDA, says COVID-19 booster shots for autumn will have to add protection against the latest Omicron sub-variants. Two widely used COVID-19 shots made by Moderna and Pfizer-BioNTech have saved millions of lives worldwide in just their first year of use. The FDA said they would be used for anyone still getting their first shots. But with immunity waning and the super-contagious Omicron family of variants getting better at escaping antibodies protection, the boosters will need an update. Waning immunity means that the effectiveness of the vaccine decreases over time.
Which of the following is a definition of the word waning?
becoming weaker or less effective
becoming stronger or more effective
becoming unlikely to change, fail, or decline
moving ones hand back and forth
What type of COVID-19 shots need updating?
booster
rooster
coaster
boaster
The FDA said they would be used for anyone still getting their first shots.
said
sad
sled
paid