“We need to be strategic about this, but we cannot abandon it,” said WHO epidemiologist Maria Van Kerkhove during an online question-and-answer session. “And what we do not want to see is the dismantling of these surveillance systems that have been put in place for covid-19.”

Although global infections have fallen about 20 percent this week compared with last week, she said the decline “may not be real,” because of the reduction in testing. Van Kerkhove had the same caveat about deaths — about 68,000 deaths were reported last week, representing a slight decline, but WHO officials have questions about some of the reporting.

Omicron has become the dominant variant, surpassing delta. WHO officials expect more variants to arise as the virus continues circulating, though they do not know whether future variants will be more or less severe or transmissible. For that reason, testing remains important.

“Now is not the time to just drop everything,” Van Kerkhove said. “We need to be very careful about what is being done, because we have to limit the spread.”