Local COVID-19 updates

[edschweppe]

As of 5PM today, the Commonwealth of Massachusetts is reporting 48 newly reported confirmed deaths (12 more than yesterday - up 33.3%) for a total of 19,821 deaths, 21,397 newly reported confirmed cases (260 more than yesterday - up 1.2%) for a total of 1,059,963 cases, and 113,963 newly reported molecular tests (5,329 less than yesterday - down 4.5%).The seven day average positivity rate is 18.42%, compared to 16.44% yesterday. The state also reported 4 newly reported probable deaths (2 more than yesterday - up 100.0%) for a total of 452 and 1,306 newly reported probable cases (357 more than yesterday - up 37.6%) for a total of 80,651. Combining the confirmed and probable numbers gives 52 new deaths for a total of 20,273 and 22,703 new cases for a total of 1,140,614. There were 1,954 COVID-19 patients in hospital (137 more than yesterday - up 7.5%), 387 COVID-19 patients in ICUs (5 more than yesterday - up 1.3%) and 243 COVID-19 patients on ventilators (intubated) (7 less than yesterday - down 2.8%).

Of the four overview trends (formerly the Page 2 "key metrics"), the 7-day average of newly confirmed cases is 9,408.0 (1,771 more than yesterday - up 23.2%), 14,600% above the lowest observed value of 64.0 on 6/25/2021 and 9.0% below the highest observed value of 10,315.0 on 12/29/2021. The 7-day weighted average of positive molecular test rate is 18.42% (0 more than yesterday - up 12.1%), 5,874% above the lowest observed value of 0.3% on 6/25/2021 and 33% below the highest observed value of 27.7% on 4/15/2020. The 7-day average number of COVID-19 patients in hospital is 1,698.0 (40 more than yesterday - up 2.4%), 1,897% above the lowest observed value of 85.0 on 7/9/2021 and 57% below the highest observed value of 3,874.0 on 4/27/2020. The 7-day average number of COVID-19 deaths is 28.0 (2 more than yesterday - up 7.7%), 2,700% above the lowest observed value of 1.0 on 7/11/2021 and 84% below the highest observed value of 175.0 on 4/24/2020.

Statewide, hospitals reported 8,839 non-ICU beds, of which 6,495 (73.5%) were occupied by non-COVID patients, 1,567 (17.7%) were occupied by COVID patients, and 777 (8.8%) remained available. Hospitals also reported 1,248 ICU beds, of which 676 (54.2%) were occupied by non-COVID patients, 387 (31.0%) were occupied by COVID patients, and 185 (14.8%) remained available. By comparison, hospitals reported yesterday a total of 8,867 non-ICU beds, of which 6,612 (74.6%) were occupied by non-COVID patients, 1,435 (16%) were occupied by COVID patients, and 820 (9.2%) remained available. Hospitals also reported yesterday a total of 1,268 ICU beds, of which 709 (55.9%) were occupied by non-COVID patients, 382 (30.1%) were occupied by COVID patients, and 177 (14.0%) remained available.

Two weeks ago, the 7 day confirmed case average was 3,648.0, the 7 day confirmed deaths average was 24.0, the 7 day hospitalization average was 1,375.0, and the 7 day weighted average positivity rate was 5.77%.

One year ago, the 7 day confirmed case average was 3,000.0, the 7 day confirmed deaths average was 60.0, the 7 day hospitalization average was 2,192.0, and the 7 day weighted average positivity rate was 8.60%.

The daily raw data file used to create this report is available here.

Day-over-day deaths (48) are up a lot. Cases (at 21,397) are up slightly, but still breaking the all-time record for newly reported confirmed cases set just ... yesterday. Hospitalizations are also up yet again, at 1,954; not a record, but the highest that number has been since January 25. All the seven-day averages are up again; the state is now reporting an average 9,408 new cases per day (far ansd away the highest of the pandemic), while the percent-postive rate is now at 18.42%, which the state hasn't seen since the catastrophic initial wave on April 30, 2020.

Scarily, the skyrocketing percent-positive means that the skyrocketing case counts are almost certainly massive undercounts.

The slightly good news is that we're beginning to see why the Omicron variant causes less severe illness; it apparently has a hard time getting into the lungs:

A spate of new studies on lab animals and human tissues are providing a possible explanation of why the omicron variant causes milder disease than previous versions of the coronavirus.

In studies on mice and hamsters, omicron produced less-damaging infections, often limited largely to the upper airway: the nose, throat and windpipe. The variant did much less harm to the lungs, where previous variants would often cause scarring and serious breathing difficulty.

"It's fair to say that the idea of a disease that manifests itself primarily in the upper respiratory system is emerging," said Roland Eils, a computational biologist at the Berlin Institute of Health, who has studied how coronaviruses infect the airway.

In November, when the first report on the omicron variant came out of South Africa, scientists could only guess at how it might behave differently from earlier forms of the virus. All they knew was that it had a distinctive and alarming combination of more than 50 genetic mutations.

Previous research had shown that some of these mutations enabled coronaviruses to grab onto cells more tightly. Others allowed the virus to evade antibodies, which serve as an early line of defense against infection. But how the new variant might behave inside of the body was a mystery.

[ ... ]

But as cases skyrocketed, hospitalizations increased only modestly. Early studies of patients suggested that omicron was less likely to cause severe illness than other variants, especially in vaccinated people. Still, those findings came with a lot of caveats.

For one thing, the bulk of early omicron infections were in young people, who are less likely to get seriously ill with all versions of the virus. And many of those early cases were happening in people with some immunity from previous infections or vaccines. It was unclear whether omicron would also prove less severe in an unvaccinated older person, for example.

Experiments on animals can help clear up these ambiguities, because scientists can test omicron on identical animals living in identical conditions. More than a half-dozen experiments made public in recent days all pointed to the same conclusion: Omicron is milder than delta and other earlier versions of the virus.

On Wednesday, a large consortium of Japanese and American scientists released a report on hamsters and mice that had been infected with either omicron or one of several earlier variants. Those infected with omicron had less lung damage, lost less weight and were less likely to die, the study found.

Although the animals infected with omicron on average experienced much milder symptoms, the scientists were particularly struck by the results in Syrian hamsters, a species known to get severely ill with all previous versions of the virus.

"This was surprising, since every other variant has robustly infected these hamsters," said Dr. Michael Diamond, a virus expert at Washington University and a co-author of the study.

Several other studies on mice and hamsters have reached the same conclusion. (Like most urgent omicron research, these studies have been posted online but have not yet been published in scientific journals.)

The reason that omicron is milder may be a matter of anatomy. Diamond and his colleagues found that the level of omicron in the noses of the hamsters was the same as in animals infected with an earlier form of the coronavirus. But omicron levels in the lungs were one-tenth or less of the level of other variants.

A similar finding came from researchers at the University of Hong Kong who studied bits of tissue taken from human airways during surgery. In 12 lung samples, the researchers found that omicron grew more slowly than delta and other variants did.

The researchers also infected tissue from the bronchi, the tubes in the upper chest that deliver air from the windpipe to the lungs. And inside of those bronchial cells, in the first two days after an infection, omicron grew faster than delta or the original coronavirus did.

These findings will have to be followed up with further studies, such as experiments with monkeys or examination of the airways of people infected with omicron. If the results hold up to scrutiny, they might explain why people infected with omicron seem less likely to be hospitalized than those with delta.

Coronavirus infections start in the nose or possibly the mouth and spread down the throat. Mild infections do not get much further than that. But when the coronavirus reaches the lungs, it can do serious damage.

Immune cells in the lungs can overreact, killing off not just infected cells but uninfected ones. They can produce runaway inflammation, scarring the lung's delicate walls. What's more, the viruses can escape from the damaged lungs into the bloodstream, triggering clots and ravaging other organs.

[ ... ]

While these studies clearly help explain why omicron causes milder disease, they do not yet answer why the variant is so good at spreading from one person to another. The United States logged more than 580,000 cases on Thursday alone, the majority of which are thought to be omicron.

"These studies address the question about what may happen in the lungs but don't really address the question of transmissibility," said Sara Cherry, a virus expert at the Perelman School of Medicine at the University of Pennsylvania.

The town of Acton's current Google Data Studio dashboard is showing 176 active and 1,711 cumulative cases as of December 30. The most recent "newsflash style update" at 7PM on December 21, 2021, the town reported 1538 cumulative cases with 89 individuals in isolation, 1417 recovered and 32 fatalities.