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latest news COVID a lingering threat in California thanks to BA.4, BA.5

The growing dominance of two new, ultra-contagious Omicron subvariants prolongs a surge of coronavirus cases in California and is prompting growing concerns from health officials that the coming weeks could see significant spread and increase in hospitalizations.

BA.4 and BA.5 are now believed to be responsible for most new infections nationwide. The strains are of particular concern because they are not only particularly contagious, but also able to re-infect those who have survived a previous infection with Omicron.

When it comes to BA.4 and BA.5, their “superpower is reinfection,” said Dr. Peter Chin-Hong, an infectious disease expert at UC San Francisco.

Additionally, “there is strong evidence that they can spread even faster than other subvariants,” said Los Angeles County Public Health Director Barbara Ferrer.

“There were also disturbing findings in laboratory studies, which revealed that BA.4 and BA.5 were better able to infect lung cells than the earlier Omicron subvariant BA.2,” said she declared.

BA.4 and BA.5 are likely to affect countries and regions differently, depending on the overall level of immunity and the number of elderly and medically vulnerable people. But “all information to date points to the need for us to prepare for the likelihood of significant transmission in the coming weeks,” Ferrer said.

“Due to the uncertainty of exactly how these new subvariants will affect us in LA County, it remains important to use whatever measures work to reduce the risk of COVID-19,” such as the vaccinations, masks, outdoor travel activities, increased indoor ventilation, testing and staying home when sick, she said.

Although reinfections with the coronavirus have been possible throughout the pandemic, the risk has increased in recent times.

“BA.4 and BA.5 are of particular concern because of their apparent ability to cause reinfections in people already infected with other Omicron subvariants,” Ferrer said.

From early December, when Omicron’s presence was first detected in California, through late February, the state reported an average of about 14,325 people newly reinfected with the coronavirus per week, data shows. from the California Department of Public Health.

This figure then fell with the initial wave of Omicron, with an average of 2,315 weekly reinfections reported from early March to early May.

But the metric has since skyrocketed – with 10,409 weekly reinfections reported from mid-May to mid-June. This timeline corresponds roughly to when BA.4 and BA.5 began circulating more widely.

“It is likely that the increase in the total number of reinfections is the result of changes in the epidemiology of COVID-19, trends in case rates and vaccination,” as well as improvements in the area of ​​data compilation. data, including the February implementation of automated processing of new reinfections, the California Department of Public Health said in a statement to The Times.

According to the latest figures from the US Centers for Disease Control and Prevention, BA.4 and BA.5 accounted for about 52.3% of cases for the week-long period ending June 25. It’s the first time the pair have accounted for a combined majority of estimated cases nationwide.

The previous week, subvariants accounted for about 37.4% of cases. The proportions are similar in the southwestern United States, which includes California, Arizona, Nevada, Hawaii, and the US Pacific territories.

While the ultimate repercussions of both strains remain to be seen, their apparent ability to re-infect people threatens to weaken one of the few lifeguards for a pandemic-weary population.

Previous waves ended because the coronavirus hit a wall, stopping when enough people were vaccinated, infected, or changed their behavior to such an extent that the virus was deprived of vulnerable hosts.

But in a world dominated by BA.4 and BA.5, those who were infected with the coronavirus – even just a few weeks ago – may not be sufficiently protected.

“The risk of reinfection is greatly increased due to the new cutting-edge mutations we are exposed to,” Dr. Eric Topol, director of the Scripps Research Translational Institute in La Jolla, wrote in a recent blog post. The first variant of Omicron “induces a fairly weak and narrow immune response, which does not help with exposure” to newer strains of Omicron, he added.

Topol called BA.5 “the worst version of the virus we have seen”.

“It takes the already extensive immune evasion to the next level and, depending on that, improved transmissibility, well beyond Omicron (BA.1) and other Omicron family variants that we have. views,” he wrote in another blog post. Publish. “You could say it’s not that bad because there hasn’t been a marked increase in hospitalizations and deaths like we’ve seen with Omicron, but that’s only because we’ve had such a striking negative impact of Omicron, for which there is at least a cross-effect immunity.”

The changing dynamics of the subvariants may help explain why the coronavirus is still transmitting at high levels across California, dashing hopes that the pandemic is over.

“I’m concerned because we’re seeing more BA.4s and BA.5s in our population, and that could be why we’re treading water at such a high level of transmission,” said Dr Paul Simon, director scientific. for the LA County Public Health Department, said in a recent briefing.

According to data released Friday, California has seen a 12% increase in coronavirus cases from mid-June, averaging more than 16,900 a day over the past week, according to data compiled by The Times. . Per capita, this represents 303 cases per week per 100,000 inhabitants.

A rate of 100 or more cases per week per 100,000 population is considered a high transmission rate.

Los Angeles County is reporting nearly 5,300 cases daily, for a weekly rate of 367 cases per 100,000 population. This is the highest case rate since early February and represents a 20% increase in cases week-on-week, erasing improvements in the case rate seen in mid-June.

This still-potent spread can be attributed to several factors, including residents largely abandoning infection prevention measures and reverting to pre-pandemic habits, the emergence of increasingly contagious strains, and the decline of the viral immunity.

It was relatively easier to avoid last summer’s Delta variant or even the first strain of Omicron that hit after Thanksgiving than the more transmissible editions of Omicron that have since emerged.

Dr Anthony Fauci, President Biden’s chief medical adviser, first tested positive for the coronavirus 2 and a half weeks ago. Xavier Becerra, secretary of the US Department of Health and Human Services, tested positive in Sacramento in mid-June – about 3.5 weeks after initially testing positive during his visit to Berlin.

Dr. Abraar Karan, an infectious disease expert at Stanford University, wondered if Becerra’s June episode of COVID-19 was caused by BA.4 or BA.5. On TwitterKaran described how he contracted the coronavirus in January, probably with Omicron’s first variant, BA.1, but was then infected again in May, probably with BA.2.12.1.

“With more immuno-evasive variants, this could be the case for many of us once again, and soon,” Karan wrote.

Any infection – whether it’s the first occurrence or a repeat one – always poses potential health problems. Although much has been said about Omicron’s relatively softer nature, he can still pack a punch.

Even if hospitalization is not necessary, COVID-19 can still cause unpleasant symptoms. And long COVID, in which conditions like fatigue, brain fog, or difficulty breathing can linger for months or years, remains a risk after each infection, though it’s likely reduced by updating on the vaccinations.

“It is prudent to remain cautious despite the decline in hospitalizations and deaths in recent months,” wrote Dr. Robert Wachter, chairman of the department of medicine at UC San Francisco. recently, adding that he has stopped dining in indoor public spaces amid high case rates in his city. “It’s all about long COVID – both prolonged symptoms and the long-term high risk of [a heart attack]stroke, diabetes, etc.

It’s a risk he knows all too well. His wife is still struggling with symptoms weeks after she was initially infected.

“A healthy 64-year-old woman who was vaccinated and boosted, she had an uneventful first bout with the virus. Yet seven weeks later, she continues to suffer from extreme exhaustion and feels like her brain is working in slow motion,” Wachter wrote in an op-ed.

As to whether BA.4 or BA.5 causes more severe disease than other members of the Omicron family, the jury is out.

Although the World Health Organization recently noted that the currently available evidence does not indicate a change in the severity of illness associated with either, the agency also stated that their increasing prevalence” coincided with an increase in cases” in several regions, with these increases leading to increased hospitalizations in some countries.

BA.5, Topol said, “resulted in a marked increase in hospitalizations in Portugal where it quickly became dominant,” and is having a similar effect in many European countries and Israel.

A wave powered by BA.4 and BA.5 in South Africa was reported to be associated with somewhat lower death rates than its first Omicron waves, Ferrer said. But, still in Portugal, “the increase in BA.4 and BA.5 appears to be associated with a fairly similar mortality rate” to her first Omicron wave, she said.

It would not be surprising if the ability of existing vaccines to protect against serious disease erodes when tested against BA.5, Topol said. After all, vaccines plus a booster resulted in 95% protection against severe disease caused by the Delta variant, but this was lowered to 80% when tested against early Omicron BA.1 and BA.2, he said.

A major question is whether the potential deployment of an Omicron-specific booster later this year will help. Given how much the variant has changed over the past seven months, there are concerns that such an offering will be relatively obsolete by the time it becomes available.

It is increasingly important, Topol said, to accelerate work on a new generation of vaccines, such as a nasal vaccine to better protect people against infection, and vaccines that can work against all variants of coronavirus.



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