(CNN) — Almost two and a half years since the coronavirus pandemic began, the most infectious and transmissible variant to date has arrived: BA.5.
Repeated waves of covid-19 have left millions of people dead, and only vaccines have helped curb the death toll. Now the virus is spreading again: evolving, evading immunity and leading to a surge in cases and hospitalizations. The most recent version of its transformations, the BA.5 variant, is a clear sign that the pandemic is far from over.
This new member of omicron, along with the closely related variant BA.4, has already generated a global increase in cases: 30% in the last two weeks alone, according to the World Health Organization (WHO).
In Europe, omicron subvariants have driven an increase of about 25% in cases. Although Dr. Michael Ryan, executive director of the WHO Health Emergencies Programme, said that number could actually be higher, given the “near collapse in screening.”
The BA.5 variant is also spreading in China, where concerns are growing that major cities will soon re-implement strict lockdown measures that were recently lifted.
And this same descendant of Omicron became the dominant strain in the United States. There it accounted for 65% of new infections last week, according to the Centers for Disease Control and Prevention (CDC).
“We’ve seen how quickly this virus evolves. We’ve been planning and preparing for this moment. And the message that I want to get across to Americans is that BA.5 is something that we’re keeping a close eye on. And more importantly, we know how to handle it,” Dr. Ashish Jha, White House COVID-19 response coordinator, said at a news conference Tuesday.
That same day, the WHO Emergency Committee indicated that covid-19 continued to be a public health emergency of international concern, the highest level of alert that was declared for the first time on January 20, 2020. This due to the rising cases, ongoing viral mutation, and increasing pressure on already overburdened health systems.
The committee ––composed of independent experts–– highlighted in a statement the challenges of the current global response to covid-19. Among them, a decrease in screening tests and irregular genome sequencing. Which begs the question of how accurate any nation could be of reasonably monitoring the BA.5 variant.
Official data drastically underreports the actual number of US infections, epidemiologists warn. A situation that puts the country in a critical blind spot, as the most transmissible variant of coronavirus so far gains ground. Some experts believe the number of new infections could reach 1 million cases every day in the general US population, which is 10 times the official count.
As for how to deal with the new wave of Covid-19, Jha urged Americans over the age of 50 to get a second booster dose. Adults who are up to date on their vaccination schedule are less likely to be hospitalized than those who have not been vaccinated. But only one in four adults over the age of 50 in the US has received the recommended second booster, data the CDC compiled shows.
The United States health authorities are urgently working on a plan that allows the second booster dose against covid-19 for all adults. This was confirmed by a senior White House official to CNN on Monday. Right amid fears that immunity in younger adults may be waning, as covid-19 cases with the BA.5 variant dominate.
What makes the BA.5 variant different?
Eric Topol, a cardiologist and professor of molecular medicine at Scripps Research, called the BA.5 variant “the worst version of the virus we’ve ever seen.” As he explained in a recent newsletter, it “takes the already extensive immune escape to the next level. And based on that, it improves transmissibility,” far beyond previous versions of omicron.
In other words, the BA.5 variant can easily evade immunity from previous infections and vaccinations, increasing the risk of reinfection. Although the variant does not appear to cause more severe disease, Topol said in an interview with CNN on Monday that, given the extent of BA.5’s immune evasion, he expects to see an escalation in hospitalizations, as has occurred in Europe and elsewhere. places where the variant has strengthened. “A good thing is that it doesn’t seem to be accompanied by higher admissions to intensive care units, nor by more deaths like the previous variants. But, this is definitely worrying,” he added.
Public health experts in the US may take some comfort in the variant’s trajectory in Europe. The WHO’s Ryan said last week that while many countries on that continent are seeing an increase in hospitalizations, “what we’re not seeing is an increase in intensive care unit admissions. working and it’s those gaps in immunity that are causing the problem.
But still, sharp reductions in COVID-19 surveillance around the world hamper epidemiologists’ efforts to track the evolution of the virus.
“Omicron sub-variants, such as BA.4 and BA.5, continue to drive waves of cases, hospitalizations and deaths around the world,” WHO Director-General Tedros Adhanom Ghebreyesus told a news conference on Tuesday. “Surveillance has been significantly reduced, including testing and sequencing, making it increasingly difficult to assess the impact of variants on transmission, disease characteristics, and the effectiveness of mitigation measures,” he added.
“New waves of the virus demonstrate once again that the [pandemia] of covid-19 is not over,” he insisted.