Tag Archives: Omicron variant

Virus mutations aren’t slowing down. New omicron subvariant proves it.

Coronavirus testing sites remain in business more than two years after the pathogen emerged. A medical worker administers tests April 18 in New York. (Spencer Platt/Getty Images)
Washington Post, By Joel Achenbach, May 1, 2022

During those terrifying early days of the pandemic, scientists offered one piece of reassuring news about the novel coronavirus: It mutated slowly. The earliest mutations did not appear to be consequential. A vaccine, if and when it was invented, might not need regular updating over time.

This proved overly optimistic.

The coronavirus, SARS-CoV-2, has had billions of chances to reconfigure itself as it has spread across the planet, and it continues to evolve, generating new variants and subvariants at a clip that has kept scientists on their toes. Two-and-a-half years after it first spilled into humans, the virus has repeatedly changed its structure and chemistry in ways that confound efforts to bring it fully under control.

And it’s not showing signs of settling down into a drowsy old age. Even with all the changes so far, it still has abundant evolutionary space to explore, according to virologists who are tracking it closely. What that means in practical terms is that a virus that’s already extremely contagious could become even more so.

“This virus has probably got tricks we haven’t seen yet,” virologist Robert F. Garry of Tulane University said. “We know it’s probably not quite as infectious as measles yet, but it’s creeping up there, for sure.”

The latest member of the rogue’s gallery of variants and subvariants is the ungainly named BA.2.12.1, part of the omicron gang. Preliminary research suggests it is about 25 percent more transmissible than the BA.2 subvariant that is currently dominant nationally, according to the Centers for Disease Control and Prevention. The CDC said the subvariant has rapidly spread in the Northeast in particular, where it accounts for the majority of new infections.

“We have a very, very contagious variant out there. It is going to be hard to ensure that no one gets covid in America. That’s not even a policy goal,” President Biden’s new covid-19 coordinator, Ashish Jha, said in his inaugural news briefing Tuesday.

He was answering a question about Vice President Harris, who recently tested positive for the virus and went into isolation. Harris had recently been boosted for the second time — her fourth shot of vaccine.

Her case highlights what has become painfully obvious in recent months: No amount of vaccination or boosting can create a perfect shield against infection from SARS-CoV-2. What the vaccines do very well, however, is greatly reduce the risk of severe illness. That is hugely consequential as a matter of public health, as is the wider use of therapeutics, such as the antiviral Paxlovid.

The vaccines currently deployed were all based on the genomic sequence of the original strain of the virus that spread in late 2019 in Wuhan, China. They essentially mimic the spike protein of that version of the virus and trigger an immune response that is protective when the real virus shows up.

But the variants that have emerged can evade many of the neutralizing antibodies that are the immune system’s front line of defense.

“It’s evolving at a fairly rapid rate,” said Jesse Bloom, a computational biologist at the Fred Hutchinson Cancer Research Center in Seattle. “I do think we need to aggressively consider whether we should update vaccines, and do it soon.”

Vaccines have reduced the virus’s worst effects. Community of Hope clinical nurse manager Imani Mark injects Ezekiel Akinyeni with a shot July 31, 2021, in D.C. (Craig Hudson/For the Washington Post)

BA.2.12.1 brings the novel coronavirus up another step on the contagiousness scale. Its close relative, BA.2, was already more transmissible than the first omicron strain that hit the country in late 2021.

And omicron was more transmissible than delta, and delta was more transmissible than alpha, and alpha was more transmissible than earlier variants that did not have the glory of a Greek alphabet name.

Most mutations are not advantageous to the virus. But when a mutation offers some advantage, the process of natural selection will favor it.

There are two fundamental ways that the virus can improve its fitness through mutation. The first could be described as mechanical: It can become innately better at infecting a host. Perhaps it improves its ability to bind to a receptor cell. Or perhaps the mutation allows the virus to replicate in greater numbers once an infection has begun — increasing the viral load in the person and, commensurately, the amount of virus that is shed, potentially infecting other people.

The other strategy involves the workaround of immunity. The human immune system, when primed by vaccines or previous infection to be alert for a specific virus, will deploy antibodies that recognize and neutralize it. But mutations make the virus less familiar to the immune system’s front-line defense.

The omicron subvariants keep coming: Scientists in South Africa have identified BA.4 and BA.5, which have mutations that were seen in earlier variants and are associated with immune evasion. Caseloads there are rising. New laboratory research, posted online Sunday but not yet peer-reviewed, indicated that the emerging subvariants are adept at eluding the neutralizing antibodies seen in people who recovered from infections with the original omicron variant. The authors of the study concluded that BA.4 and BA.5 have the “potential to result in a new infection wave.”

“The evolution is much more rapid and expansive than we initially estimated,” said Michael T. Osterholm, a University of Minnesota infectious-disease expert. “Every day I wake up, I fear there will be a new subvariant that we will have to consider. … We’re seeing subvariants of subvariants.”

Garry, the Tulane scientist, points out that mutations in the virus do not change its appearance dramatically. In fact, he said, even the heavily mutated variants don’t look much different from the original Wuhan strain, or different from other coronaviruses that cause common colds. These are subtle changes.

Garry has a software program that allows him to create a graphic image of the virus, and even rotate it, to observe the locations of mutations and draw inferences for why they matter. On Friday, asked about BA.2.12.1, and why it is spreading, he noted it has a mutation, named S704L, that probably destabilizes a portion of the spike protein on the virus’s surface. That essentially loosens up part of the spike in a way that facilitates infection.

This S704L mutation distinguishes this subvariant from BA.2.

The “704” refers to the 704th position for an amino acid on a chain of roughly 1,100 amino acids that form the protein. The S is one type of amino acid (“serine”) seen in the original strain of the virus, and the L (“leucine”) is what is there after the mutation. (The mutation is caused by a change in one nucleotide, or “letter,” in the genetic code of the virus; three nucleotides encode for an amino acid.)

The virus is spreading today in the United States on an immunological landscape much different from the one it first encountered in early 2020. Between vaccinations and infections, there aren’t many people entirely naive to the virus. The latest CDC data suggest the virus has managed to infect nearly 200 million people in the nation, which has a population of about 330 million. Among children and teenagers, about three out of four have been infected, the CDC estimates.

For the new CDC study, researchers looked at blood samples from thousands of people and searched for an antibody that is found after a natural infection, but not found after vaccination. The CDC concluded that the omicron variant managed to plow through the United States population during the winter almost as if it were an entirely new virus. The country by then was largely vaccinated. And yet 80 million people, approximately, became infected for the first time in that omicron wave.

On the family tree of this coronavirus, omicron is a distant cousin of delta, alpha and the other variants that had spread earlier — it came out of virologic left field. No one is sure of the origin of omicron, but many disease experts assume it came from an immunocompromised patient with a very lengthy illness, and the virus continued to use mutations to evade the immune system’s efforts to clear it.

Technicians inside a high-security coronavirus research lab in Durban, South Africa, on Dec. 15, 2021. (Waldo Swiegers/Bloomberg)

Omicron was mercifully less likely to kill a person than previous variants. But infectious-disease experts are clear on this point: Future variants could be more pathogenic.

As if mutation wasn’t enough of a problem, the virus has another trick up its sleeve: recombination. It happens when two distinct strains infect a single host simultaneously and their genes becoming entangled. The recombination process is the origin of what’s known as omicron XE. That recombinant probably emerged from a person co-infected with the original omicron variant and the BA.2 subvariant.

It was always possible in theory, but the identification of actual recombinants provides “proof of concept,” as Jeremy Luban, a virologist at the University of Massachusetts Medical School, puts it.

The worst-case scenario would be the emergence of a variant or recombinant that renders current vaccines largely ineffective at blocking severe disease. But so far, that hasn’t happened. And no “recombinant” has spread like omicron or other recent variants and subvariants.

This is the first catastrophic pandemic to occur in the age of modern genomic sequencing. A century ago, no one knew what a coronavirus was, and even a “virus” was a relatively new concept. But today, with millions of samples of the virus analyzed at the genetic level, scientists can track mutations virtually in real time and watch the virus evolve. Scientists across the planet have uploaded millions of sequences to the database known as GISAID.

Genomic sequencing has a major limitation in that, although scientists can track changes in the genome, they don’t automatically know what each of those changes is doing to the virus. Which mutations matter most is a question that can be discerned through laboratory experiments, modeling or epidemiological surveillance, but it’s not always simple or obvious.

Erica Saphire, president of the La Jolla Institute for Immunology, speculates that omicron has mutations that have changed the virus in ways not yet understood but which make it more resistant to antibody-mediated neutralization.

“It may have acquired some new trick that we haven’t uncovered yet,” Saphire said. “It’s harder to neutralize than I would have expected, based on the number of mutations alone.”

A reality check comes from Jeremy Kamil, associate professor of microbiology and immunology at Louisiana State University Health Shreveport: “These are all SARS-CoV-2.”

What he means is that these are all variations of the same virus, despite what seems like a tremendous amount of mutation. Correspondingly, someone who gets infected with one of these new variants has the same disease as people who got infected previously.

“They got covid,” he said.

Solano COVID report – much good news, but still… 3 new deaths and 78 new infections

NOTE: The information below is not the latest.  TAP HERE for today’s latest information.

By Roger Straw, Monday, March 14, 2022

Solano County reported 78 new COVID infections today and 3 new deaths.  Good news: Solano no longer in HIGH transmission rate, Benicia falls into MODERATE transmission rate.

Solano Public Health COVID dashboard, Monday, March 14, 2022:

DEATHS:  Solano reported 3 new COVID-related deaths in today’s report.  Fifteen new deaths were reported in February, ALL over 65 years of age.  So far in March, 13 County residents were reported to have died with COVID.  A total of 409 Solano residents have now died of COVID or COVID-related causes over the course of the pandemic.

TRANSMISSION RATE: Good news: With today’s report, Solano moved out of the HIGH transmission rate and into the SUBSTANTIAL rate for the first time since Dec 22, 2021, now showing a total of 286 new cases over the last 7 days. CDC FORMULA: Based on Solano County’s population, 450 or more cases in 7 days places Solano in the CDC’s population-based definition of a HIGH transmission rate.  We would need to drop below 225 cases in 7 days to show MODERATE community transmission.

>ACTIVE CASES: Good news: Solano reported 303 ACTIVE cases today, down from 425 at last report, our lowest number since Dec 15 2021.

CASES BY CITY – Monday, March 14, 2022:

  • BENICIA added 4 new cases today, a total of 3,108 cases since the outbreak began.  TRANSMISSION RATE: Good news! Benicia’s 7-day case count fell to only 13 today, dropping Benicia into the CDC’s MODERATE range for the first time since Dec 6, 2021.  For a city with Benicia’s population, anything over 27 cases in 7 days is considered HIGH TRANSMISSION, and 14 to 27 cases is considered SUBSTANTIAL TRANSMISSION. (See chart below.)

  • Dixon added 1 more case today, total of 4,318 cases.
  • Fairfield added 17 new cases today, total of 22,504 cases.
  • Rio Vista added 0 new cases today, total of 1,185 cases.
  • Suisun City added 5 new cases today, total of 5,888 cases.
  • Vacaville added 17 new cases today, a total of 21,518 cases.
  • Vallejo added 34 new cases today, a total of 25,359 cases.
  • Unincorporated added 0 new cases today, a total of 199 cases.

TEST RATE:  Solano County’s 7-Day Percent Positive Test Rate has fallen dramatically in March, down today to 5% today. Even at this lower rate, SOLANO DOES NOT COMPARE FAVORABLY: The CALIFORNIA 7-day % positive rate was steady today at only 1.6%[Source: Johns Hopkins Coronavirus Tracking Center] and the U.S. 7-day % positive rate was only 2.7% today. [Source: CDC COVID Data Tracker.] 

HOSPITALIZATIONS:

CURRENT: Good news: the number of those currently hospitalized with COVID in Solano County fell today from 25 to only 13 personsCurrent hospitalizations don’t tell the whole story, though, as it reflects both admissions and discharges.  Only from the increase in total hospitalizations can we know how many new admissions have come into our hospitals as of this date.

TOTAL hospitalizations over the course of the pandemic: Solano updated its Age Group and Race/Ethnicity charts today, adding 2 new hospitalizations, for a pandemic total of 3,767.

ICU Bed Availability in Solano County increased slightly today from 45% to 46%, in the County’s GREEN safe zone .

Ventilator Availability  Good news: Ventilators rose today from 68% to 80% available, in the County’s GREEN safe zone. 


HOW DOES TODAY’S REPORT COMPARE?  See recent reports and others going back to April 20, 2020 in my ARCHIVE of daily Solano COVID updates (an excel spreadsheet).

Click green text above or on the image.

>The data on this page is from the Solano County COVID-19 Dashboard.  The Dashboard is full of much more information and (as of 3/14/2022) is updated Monday and Thursday between 4 and 6pm.  On the County’s dashboard, you can hover a mouse or click on an item for more information.  Note the tabs at top for “Summary, Demographics” and “Vaccines.”  Click here to go to today’s Solano County Dashboard.

See also my BENINDY ARCHIVE of daily Solano COVID updates (an excel spreadsheet).  I have also archived the hundreds of full CORONAVIRUS REPORTS posted here almost daily on the Benicia Independent since April 2020.

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Solano County’s final MWF COVID report: 136 new infections, 98 previously undisclosed hospitalizations

NOTE: The information below is not the latest.  TAP HERE for today’s latest information.

By Roger Straw, Friday, March 11, 2022
[Note: The information below is from Solano County Public Health’s final Mon-Wed-Fri update.  Starting next week, Solano will update it’s COVID-19 Dashboard only on Mondays and Thursdays.  Barring a new surge, I will follow on that same schedule.  – R.S.]

Solano County reported 136 new COVID infections today and 98 new hospitalizations.

Solano Public Health COVID dashboard, Friday, March 11, 2022:

NOTICE: Solano County Public Health will update its COVID Dashboard ONLY ON MONDAYS & THURSDAYS starting next week, Mon 3/14.

DEATHS:  Solano reported no new deaths in today’s report.  Fifteen new deaths were reported in February, ALL over 65 years of age.  So far in March, 10 County residents were reported to have died with COVID.  A total of 406 Solano residents have now died of COVID or COVID-related causes over the course of the pandemic.

Dr. Matyas explains huge increase in COVID cases

TRANSMISSION RATE: With last Monday’s huge increase in case numbers, Solano moved back into the HIGH transmission rate and remains there today, with a total of 4,323 new cases over the last 7 days. But the County has explained that many of Monday’s new cases are based on a ‘different testing procedure’ and predate our last 7 days, so we may not know Solano’s true 7-day case count until next Monday, 3/14. (See also Solano Public Health Director explains…CDC FORMULA: Based on Solano County’s population, 450 or more cases in 7 days places Solano in the CDC’s population-based definition of a HIGH transmission rate.  We would need to drop below 225 cases in 7 days to rate as having only MODERATE community transmission.

>ACTIVE CASES: Solano reported 425 ACTIVE cases today, down from 429 at last report, but still far above the County’s 329 active cases on December 1.

CASES BY CITY – Friday, March 11, 2022:

  • BENICIA added 6 new cases today, a total of 3,104 cases since the outbreak began.  TRANSMISSION RATE: The County’s extraordinary update on Monday pushed Benicia’s 7-day case count well into the HIGH range and continues HIGH today at 80 CASES.  But the County has explained that many of these new cases are based on a ‘different testing procedure’ and predate our last 7 days, so we may not know Benicia’s true 7-day case count until next Monday, 3/14.  For a city with Benicia’s population, anything over 27 cases in 7 days is considered HIGH TRANSMISSION. (See chart below.)

  • Dixon added 8 more cases today, total of 4,317 cases.
  • Fairfield added 41 new cases today, total of 22,487 cases.
  • Rio Vista added 1 new case today, total of 1,185 cases.
  • Suisun City added 15 new cases today, total of 5,883 cases.
  • Vacaville added 34 new cases today, a total of 21,501 cases.
  • Vallejo added 31 new cases today, a total of 25,325 cases.
  • Unincorporated added 0 new cases today, a total of 199 cases.

TEST RATE:  Solano County’s 7-Day Percent Positive Test Rate has fallen dramatically in March, down today to 6% today. Even at this lower rate, SOLANO DOES NOT COMPARE FAVORABLY: The CALIFORNIA 7-day % positive rate was steady today at only 1.6%[Source: Johns Hopkins Coronavirus Tracking Center]

HOSPITALIZATIONS:

CURRENT The number of those currently hospitalized with COVID in Solano County fell today from 29 to 25 persons.  Current hospitalizations don’t tell the whole story, as it reflects both admissions and discharges.  Only from the increase in total hospitalizations can we know how many new admissions have come into our hospitals as of this date.

TOTAL hospitalizations over the course of the pandemic: Solano Public Health played catch-up today, updating its Age Group and Race/Ethnic charts today, adding 98 previously undisclosed hospitalizations, for a pandemic total of 3,765(The County’s hospitalization numbers for Race/Ethnicity is less accurate, but presented here to show relative percentages.)

ICU Bed Availability in Solano County fell today from 49% to 45%, in the County’s GREEN safe zone .

Ventilator Availability  rose today from 64% to 68% available, but still in the GREEN safe zone. 


HOW DOES TODAY’S REPORT COMPARE?  See recent reports and others going back to April 20, 2020 in my ARCHIVE of daily Solano COVID updates (an excel spreadsheet).

Click green text above or on the image.

>The data on this page is from the Solano County COVID-19 Dashboard.  The Dashboard is full of much more information and (as of 3/14/2022) is updated Monday and Thursday between 4 and 6pm.  On the County’s dashboard, you can hover a mouse or click on an item for more information.  Note the tabs at top for “Summary, Demographics” and “Vaccines.”  Click here to go to today’s Solano County Dashboard.

See also my BENINDY ARCHIVE of daily Solano COVID updates (an excel spreadsheet).  I have also archived the hundreds of full CORONAVIRUS REPORTS posted here almost daily on the Benicia Independent since April 2020.

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Solano County reports 4 more COVID deaths and 72 new cases today

NOTE: The information below is not the latest.  TAP HERE for today’s latest information.

By Roger Straw, Wednesday, March 9, 2022
[Note: I requested and received an email clarification from Solano County Public Health Officer Bela Matyas regarding Monday’s huge increase in our County’s COVID cases.  Dr. Matyas explained in rather technical terms the ‘different testing procedure’ that led to Monday’s sudden reporting of 4,115 previously undisclosed cases and the strange drop in the number of known hospitalizations.  I’m working on a post to share the new methodology – hopefully tomorrow, stay tuned….  – R.S.]

Solano County reported 72 new COVID infections today, 4 new deaths.

Solano Public Health COVID dashboard, Wednesday, March 9, 2022:

NOTICE: Solano County Public Health will update its COVID Dashboard ONLY ON MONDAYS & THURSDAYS as of March 14, 2022

DEATHS:  Solano reported four new deaths in today’s report, one relatively young person aged 18-49 and three age 65+.  Trending: Fifteen new deaths were reported in February, ALL over 65 years of age.  So far in March, 10 more County residents were reported to have died with COVID.  A total of 406 Solano residents have now died of COVID or COVID-related causes over the course of the pandemic.

TRANSMISSION RATE: With Monday’s huge corrections, Solano moved back into the HIGH transmission rate and remains there today, with a total of 4,325 new cases over the last 7 days. But the County has explained that many of Monday’s new cases are based on a ‘different testing procedure’ and predate our last 7 days, so we may not know Solano’s true 7-day case count until another week goes by.  CDC FORMULA: Based on Solano County’s population, 450 or more cases in 7 days places Solano in the CDC’s population-based definition of a HIGH transmission rate.  We would need to drop below 225 cases in 7 days to rate as having only MODERATE community transmission.

ACTIVE CASES: Solano reported 429 ACTIVE cases today, down from 456 at last report, but still far above the County’s 329 active cases on December 1.

CASES BY CITY – Wednesday, March 9, 2022:

  • BENICIA added 3 new cases today, a total of 3,098 cases since the outbreak began.  TRANSMISSION RATE: The County’s extraordinary update on Monday pushed Benicia’s 7-day case count well into the HIGH range and continues HIGH today at 80 CASES.  But the County has explained that many of these new cases are based on a ‘different testing procedure’ and predate our last 7 days, so we may not know Benicia’s true 7-day case count until another week goes by.  For a city with Benicia’s population, anything over 27 cases in 7 days is considered HIGH TRANSMISSION. (See chart below.)

  • Dixon reportedly (!?) had 2 fewer cases today, total of 4,309 cases.
  • Fairfield added 14 new cases today, total of 22,446 cases.
  • Rio Vista added 3 new cases today, total of 1,184 cases.
  • Suisun City added 5 new cases today, total of 5,868 cases.
  • Vacaville added 25 new cases today, a total of 21,467 cases.
  • Vallejo added 23 new cases today, a total of 25,294 cases.
  • Unincorporated added 1 new case today, a total of 199 cases.

TEST RATE:  Solano County’s 7-Day Percent Positive Test Rate shot up after Christmas and continued through February at 13%, but fell dramatically in March and remains at 7% today. Even at this lower rate, SOLANO DOES NOT COMPARE FAVORABLY: The CALIFORNIA 7-day % positive rate fell today from 1.8% to only 1.6%[Source: Johns Hopkins Coronavirus Tracking CenterAND the U.S. 7-day % positive rate fell today from 3.2% to only 2.9%. [Source: CDC COVID Data Tracker.] 

HOSPITALIZATIONS:

CURRENT The number of those currently hospitalized with COVID in Solano County fell today from 31 to 29 persons.  Current hospitalizations don’t tell the whole story, as it reflects both admissions and discharges.  Only from the increase in total hospitalizations can we know how many new admissions have come into our hospitals as of this date.

TOTAL hospitalizations over the course of the pandemic: Solano Public Health updated its Age Group chart today, adding 3 new hospitalizations, for a pandemic total of 3,667.  One of the three was age 18-49 and two were age 65+.

ICU Bed Availability in Solano County rose today from 43% to 49%, in the County’s GREEN safe zone .

Ventilator Availability  fell today from 72% to 64% available, but still in the GREEN safe zone. 


HOW DOES TODAY’S REPORT COMPARE?  See recent reports and others going back to April 20, 2020 in my ARCHIVE of daily Solano COVID updates (an excel spreadsheet).

Click green text above or on the image.

>The data on this page is from the Solano County COVID-19 Dashboard.  The Dashboard is full of much more information and updated Monday, Wednesday and Friday between 4 and 6pm.  On the County’s dashboard, you can hover a mouse or click on an item for more information.  Note the tabs at top for “Summary, Demographics” and “Vaccines.”  Click here to go to today’s Solano County Dashboard.

See also my BENINDY ARCHIVE of daily Solano COVID updates (an excel spreadsheet).  I have also archived the hundreds of full CORONAVIRUS REPORTS posted here almost daily on the Benicia Independent since April 2020.

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