Scientists in Hong Kong say the omicron variant of the coronavirus multiplies much faster in the airway passages, which could explain how the variant is spreading so fast around the globe.
A preliminary report by a team of researchers at the University of Hong Kong says laboratory experiments on tissue samples show omicron grows about 70 times faster than delta in the bronchus, the main tubes from the windpipe to the lungs.
The study also found that omicron grows 10 times slower in lung tissues than the original version, which could indicate a lower chance of a severe illness.
Lead researcher Michael Chan Chi-wai cautions that the severity of disease is not only determined by how quickly the virus replicates, but also by each person’s immune response to the infection, which could evolve into a life-threatening illness.
Dr. Chan adds that “by infecting many more people, a very infectious virus may cause more severe disease and death even though the virus itself may be less pathogenic.”
He says along with recent studies showing omicron can “partially escape immunity” from vaccines and previous infection, “the overall threat from the omicron variant is likely to be very significant.”
Omicron has now been detected in nearly 80 countries since it was first identified in southern Africa back in November. Indonesia and New Zealand are the latest countries to report their first confirmed case of the virus.
On the vaccine front, an advisory panel with the Centers for Disease Control and Prevention will meet Thursday to discuss imposing limits on the single-shot Johnson & Johnson vaccine because of continued side effects.
The vaccine has been linked to a rare yet serious blood clotting disorder that occurs predominantly among women. At least six women out of the 16 million U.S. citizens who have received the Johnson & Johnson vaccine have been diagnosed with the disorder, including one woman who died.
The blood clotting disorder first emerged in April, soon after the vaccine began to be administered across the U.S., prompting federal health officials to suspend its use for several days while a safety review was conducted. Regulators added a warning about the potential for blood clots on the vaccine’s label, but concluded that its benefits outweighed the risks.
The Johnson & Johnson vaccine trails well behind the two-dose Pfizer and Moderna vaccines in terms of demand, both as an initial dose or a booster shot.
Some information for this report came from Reuters.