-159 cases of the B117 UK variant
-1,203 cases of West Coast variant
-no cases of P1 variant, believed to have emerged in Brazil
-two cases of the South African B1351 variant -- one in Alameda and one in Santa Clara County
What we know about these variants:
-the B117 variant is believed to be about 50% more infectious. it's prevalence in the US is doubling every week
-research on the B1351 variant suggests it may make some vaccines less effective. it's an issue to keep an eye on
Some more details about B1351 in California:
In the Santa Clara County case, the person infected returned from international travel in mid-January and began experiencing symptoms several days later.
The infected person -- as well as a household member they traveled with -- followed travel quarantine guidance so they were both isolated in their apartment the entire infectious period, suggesting that they did not infect others in the county.
• • •
Missing some Tweet in this thread? You can try to
force a refresh
So the CDC changed its masking guidance yesterday to recommend tighter-fitting masks as well as double masks. But they specifically warned against layering KN95s, which surprised me given how common that combo has become
This is how they explained it when I followed-up:
KN95s and N95s work very well on their own and adding masks on top or underneath could "affect how well they fit the face and decrease their effectiveness" and also make them hard to breathe through and uncomfortable, officials say.
"Masks that are not comfortable may not be worn by people as long as they are needed. It's important for consumers to find a mask that fits well but that also is comfortable enough that they can wear it for prolonged periods, if needed," reads a CDC statement sent to me.
LA County officials say that food and agriculture workers will become eligible for vaccination here in the next two to three weeks.
That sectors breaks down like this. About half a million people in this category in LA County.
LA County officials say that childcare and education workers will become eligible for vaccination within the next two to three weeks. There are nearly 700,000 people who qualify under this category in the county.
How many people are wearing cloth masks on top of KN95s?
The CDC's new masking guidance recommends wearing a cloth mask over a disposable mask, but it asks that people NOT layer KN95s. KN95s are meant to be worn on their own, it says.
I'm trying to find out more soon on why they're recommending this, but I'm wondering if it's because KN95s have a structure to them and if you put something on top it might flatten the mask, and reduce the tightness of the seal? Hopefully will know more soon.
The CDC is updating its mask guidance today to recommend new ways to make masks fit more tightly, including double-masking, knotting the ear loops or using a moldable nose wire. This is based on new science released today.
CDC researchers conducted an experiment in which they simulated aerosolized COVID-19 transmission between two people, and found that exposure was reduced by more than 95% when both people were wearing a cloth mask over a medical procedure mask.
"Masks work, and work best when they have a good fit and are worn correctly," says CDC director Dr. Rochelle Walensky.
Officials say that there are now five confirmed cases of the B117 coronavirus variant -- often called the UK strain -- in LA County.
LA County public health director Barbar Ferrer: "I would just note: there's no way that we don't have a fair amount of variant circulating, a fair amount of mutated virus circulating. It's just a question of how much and does it become dominant."