Many celebrated the lifting of California regional stay-at-home orders on Monday and increased opportunities for outdoor dining, youth sports competitions and other social gatherings.
But a group of researchers at UC San Diego, Scripps Research and other respected institutions warned on Tuesday that the dominance of the new virus variant first seen in Britain makes this the wrong time to take any action that could increase the collective size of the community. from social contacts.
Standing before the San Diego County Board of Trustees, Natasha Martin, a university infectious disease modeller with a doctorate in mathematical biology from the University of Oxford, noted that B.1.1.7, the variant first seen in San Diego County on December 30, was estimated. 50 percent to 70 percent more transmissible than the early versions that swept across the world after popping up in China.
Things are much different now than in late 2019 and early 2020, with vaccines now increasingly available and significant indications they will be effective against the new variant, at least to some extent. But it is important to vaccinate large sections of the human population – many estimate around 70 percent – to achieve a herd immunity level that prevents infection from spreading rapidly from person to person.
Martin’s presentation to the board on Tuesday stated that, while vaccination has increased significantly, the spike in the number of social contacts, combined with the significantly greater spreadability of B.1.1.7, could lead to a spike in infections that goes beyond vaccination efforts.
“In a scenario where contact rates increase, within two weeks, due to reopening activities, a substantial spike will occur, exceeding our health care capacity, in all scenarios, even with vaccinations,” said Martin.
Only because it is able to spread faster than other variants that are its competitors, B.1.1.7, said Martin, is expected to quickly become the dominant variant in circulation. The speed of that transition, he said, is proportional to the number of people in the population sharing space and air, especially if they are not wearing masks.
Change, he said, was inevitable. This has already happened in England, Portugal and Ireland.
Increasing numbers of collections, especially if done without masks, mean San Diego, and California in general, “could potentially see a scenario of 7,000 cases per day”.
That will be significantly more than the previous record of 4,550 set on January 7.
So while many are celebrating the chance to get out and about more now that stay-at-home orders are back on the shelves, experts suggest otherwise.
“I can’t stress this enough; with the emergence of B.1.1.7 and other strains that may be more contagious, and potentially more virulent, it is time to multiply the reduction in transmission and the expansion of vaccination, ”said Martin.
“We have to be very careful about reopening and monitoring the situation closely.”
This is quite difficult for a situation that gradually looks better over 10 consecutive days.
The county COVID-19 report Tuesday listed 1,434 new cases with the number of patients still high but declining in hospital beds with confirmed coronavirus infections. The report listed 46 additional deaths, but, while tragic, they tended to come long after infection. Thus, the increase in mortality reflects the infectious activity that occurred in the past few weeks.
The state, as briefings Monday and Tuesday showed, continues to see its infection rate drop, leading to the cancellation of stay-at-home orders.
Fewer infections, officials said, led to models showing numbers of intensive care falling significantly through February. Southern California, for example, which recently had an estimated 0 percent ICU capacity, is expected to increase to 33 percent by February 21.
It was unclear Tuesday whether the state model took into account predictions of dominance of the more transmissible B.1.1.7 variant.
An email, sent Tuesday afternoon by officials at the communications office at the California Department of Public Health, said that “the modeling used in projecting ICU capacity takes into account current conditions, including recently observed rates of transmission.”
That sentence seems to suggest that the data used to make the decision to delete stay-at-home orders are, for the most part, using current trends in infection rates to predict where things will go in the future rather than trying to predict how. the dominant British variant will change things.
The state agency appeared to confirm that interpretation late Tuesday, stating in a follow-up email: “if conditions on the ground change, such as wider transmission, it is included in the model.”
It is clear, however, that the current British variant looks like a San Diego problem, rather than a California problem.
Monday’s coronavirus update includes an update on B.1.1.7, showing that there have been only 90 confirmed cases statewide so far, 87 of them in San Diego County.
Does this mean that the British variant is just a San Diego problem, a local situation that is unlikely to grow as fast as elsewhere?
Probably not, says immunologist Scripps Research and molecular biologist Kristian Andersen, whose laboratory, working with positive tests administered by UCSD, is the first to confirm the presence of the new variant in San Diego County.
Detecting the presence of B.1.1.7 requires extra work. Testing, only from certain manufacturers, which returned with only two out of three positive genetic targets served as a smoky signal that a British variant might be involved, but additional genetic analysis is needed for confirmation.
That is, in order to detect the presence of a variant, the local laboratory must use the type of test which has an accidental and completely accidental sensitivity to deletion of the variant’s genetic code, and local researchers must look for the subtle smoke. signal and also must be willing to follow up with a proper genetic analysis.
Some health departments, Andersen said, have all of these components as San Diego does, meaning that many of the positive test results that show up every day in San Diego and elsewhere are due to the variant.
“It’s definitely not localized in San Diego, although maybe it’s more common in San Diego than most other places,” said Andersen. “Unfortunately, (it is) impossible to say due to lack of oversight in most of the other places.”
On seemingly contradictory predictions, with local research consortia predicting an explosion of new cases and countries predicting a decline, particularly in intensive care admissions, both, Andersen notes, could be true.
After all, it usually takes weeks for new infections today to worsen to the point where a minority require intensive care.
“I hope we’ll see ICU admissions drop – maybe quite a lot – and make sense of the case over the next few weeks too,” he said.
Such a downturn, he added, would probably be enough to “lull us into a false sense of security that we changed it only to reappear, first gradually, but then quickly, as B.1.1.7 takes over.”
Although still small, he said, the frequency of cases of the British variant showing up in test results “is doubling roughly weekly.”
Of course, vaccination is another major variable in any coronavirus prediction algorithm.
The scenarios tested by the UCSD / Scripps model assume that the region will vaccinate about 6,000 people per day through January and about 20,000 per day by February, with about 50 percent getting protection from the first dose and 95 becoming immune after the second dose.
However, it appeared that on Tuesday the region had begun to exceed estimates of the vaccination.
Nick Macchione, director of the county health and human services agency and co-chair of testing, tracking and treatment efforts, estimates that the district’s vaccination site now ships about 12,000 vaccines per day. He said he expected inoculation efforts to rapidly increase to 25,000 doses per day with the opening of additional “super site” vaccination sites, including one in East County to be run by Sharp HealthCare and two in North County, one operated in collaboration with Palomar Health. Tri-City Medical Center, UC San Diego and county health departments. The other, serving the North County coast, will be run by Scripps Health.
“We hope to reach 70 percent of our population long before July 1,” said Macchione.
Regional health departments will take additional questions about the coronavirus on Wednesday during routine weekly COVID-19 media briefings.