Quick takes: Declassifying COVID-source intel, Cochrane mask review clarification, XBB.1.5 rise in US


Center for Infectious Disease Research and Policy.

By Lisa Schnirring

March 10, 2023

  • In a rare and strong bipartisan vote today, the US House of Representatives voted to declassify US intelligence information about the origins of SARS-CoV-2, the Associated Press and other media outlets reported. The Senate has passed a similar measure, which will now go to Biden’s desk for a signature. Two US agencies have concluded that a lab leak was the likely source of the virus in China, the US Department of Energy with low confidence and the Federal Bureau of Investigation with moderate confidence. Other US intelligence agencies, however, have not changed their assessment—also with low confidence— that the source was natural, involving a jump from animals to humans. Last week the World Health Organization pressed China on the origins and also urged countries to share what they know to help nations avoid future pandemics. Scientists have published extensive studies that support a natural source that came from a live-animal market in Wuhan, China, but so far, it’s not clear what other information US officials have that would support the lab-leak scenario.
  • The Cochrane Library today issued a statement clarifying its recent review on mask and respirator use in households and healthcare settings, which some people have used to suggest that the measure isn’t useful for preventing the spread of COVID-19. In a statement, the group said characterization of the findings is misleading, that the review was inconclusive, and that the primary evidence wasn’t able to address whether the intervention itself reduces a person’s risk of contracting or spreading the virus.
  • In updated Omicron variant proportion estimates today, the US Centers for Disease Control and Prevention (CDC) said XBB.1.5 makes up nearly 90% of cases, up from 87% the week before. The virus makes up about 80% or more of cases in all US regions. The CDC also added another subvariant to its proportion tracking, XBB.1.5.1, which makes up an estimated 1.6% of cases.