American drug maker Johnson & Johnson said Friday that its one-shot vaccine prevented COVID-19 in a large trial around the world. The vaccine, however, was less effective in South Africa where a worrisome variant is causing new infections. The Johnson & Johnson, or J&J, trial involved almost 44,000 volunteers. The company said the vaccine worked best in the United States with an efficacy rate of 72 percent. In Latin America, efficacy was 66 percent. J&J reported that South Africa saw the lowest efficacy rate of the vaccine, at 57 percent.
What does variant mean?
an exact replica
something that is different from others of the same kind
freezing temperatures
a confusing matter
How many volunteers were included in the Johnson and Johnson COVID-19 trial?
54,000
44,000
4,000
84,000
The Johnson and Johnson COVID-19 vaccine is least effective in South Africa.
The United States
South Africa
Latin America
South America