COVID-19 is still "going viral"
The novel coronavirus continues to spread faster in most of the USA, even though test positivity and other metrics show signs of hope in a few places.
Today’s headlines are below, but first, this may be a good time to review the math of viral spreading.
Have you ever heard the phrase “go viral”? When a social media post “goes viral,” it means that its visibility exploded fast. The phrase originates from actual virus behavior. Viruses have one reason to exist: to find hosts - lots of them. And each person who gets infected enables the virus to reach more people.
The virus that causes COVID-19 was observed to spread rapidly from the outset. In Wuhan, doctors estimated that each person infected typically spread the virus to an average of about six others. As the pandemic spread around the world, European researchers found that “non pharmaceutical interventions” — social distancing, masks, hand washing and in some cases, stay-at-home orders — cut the transmission rate by 50-60%.
While these measures are helpful indicators of outbreak severity and the effectiveness of interventions, scientists also caution against misusing the “R-naught” values. They are estimates and by definition, they are imprecise. Nonetheless, areas where the R-naught is lower than 1 are places where the outbreak is winding down instead of increasing.
For an informative explanation of viral math, check out this Wired article from March. (You will likely weep when you see how much lower the case counts were back then.)
Now, the stories that matter today:
The USA’s vaccine program is still far short of the Operation Warp Speed goals. Just over 2 million Americans have been vaccinated as of Monday, according to federal officials. The goal was 20 million by this coming Friday.
Some areas in China are reporting new outbreaks of COVID-19, raising concerns in advance of the Lunar New Year. With strict lockdown and other orders, the virus had been relatively well controlled once Chinese officials came to grips with the emerging infectious disease that they had denied previously.
The CDC updated its guidance on whether the COVID-19 vaccines are safe for people with certain underlying health conditions. The agency said there is no data indicating any added risk for Guillain-Barre syndrome or Bell’s Palsy. Bell’s Palsy cases observed during the clinical trials were at the same rate as in the general population, according to the FDA.
Viral load could differentiate people more likely to get severely ill. As with other viral diseases, doctors say that severity of COVID19 is a function of how much of the SARS-CoV-2 virus is in a person’s system. However, this metric has not been routinely reported out by labs conducting COVID-19 testing. That may soon change. Florida is the first state to require this, according to the New York Times.
For an interesting, informative discussion of why getting vaccines into people’s arms is proving harder than some had expected, read this Twitter thread started by Boston University School of Public Health Dean Dr. Ashish Jha. Many of the comments add useful detail.
A World Health Organization scientist notes that COVID-19 is bad, but “it is not necessarily the big one” that virologists have predicted for years.
Musician Mark Almond is making good use of his time on hiatus from the San Francisco Symphony. Almond, who has medical degrees from Cambridge and Oxford universities and a Ph.D. in virology from Imperial College in London, has stepped into a lab at UCSF to work on the biology of SARS-CoV-2, which causes COVID-19.
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