Health experts around the world are sounding the alarm as they begin to report that Omicron BA.5, the strain of coronavirus that is currently outpacing other infection variants and has become the dominant strain in the United States and abroad, has the ability to re-infect people within weeks. contract the virus.
Andrew Roberston, the head of health in Western Australia, told News.com.au that although it used to be wise that most people would retain some level of protection against re-infection if they were vaccinated or had retained some level of natural immunity due to a recent contraction of the virus, this was not the case with the most recent strain.
“What we are seeing is an increasing number of people who have been infected with BA.2 and who are infected after four weeks,” explained the doctor during an interview with the Australian media. “So maybe six to eight weeks they develop a second infection, and it’s almost certainly BA.4 or BA.5.”
The ability of the BA.4 and BA.5 strains to re-infect individuals who in previous waves of Covid-19 had stronger immunity has led some experts to start calling this latest strain the most transmissible to date.
“They take over, so they’re clearly more contagious than earlier omicron variants,” David Montefiori, a professor at the Human Vaccine Institute at Duke University Medical Center, said in an interview with NBC News.
Federal estimates released Tuesday by the Center for Diseases Control and Prevention show BA.5 has now overtaken the dominant strain in the United States, accounting for about 54% of cases for the week ending July 2, 2022.
And although the average number of new cases the United States sees each day has regularly hovered between 95,000 and 115,000, according to data from The New York Times, experts fear that a combination of home testers not reporting positive cases, a closure of government-funded testing centers and an increase in states halting their daily data updates have led to a lesser picture of the real penetration of this new strain in the country.
A study published in Science Last week confirmed the troubling reality that many may have already experienced anecdotally with multiple consecutive reinfections: these two new subvariants elude protection from previous infections and vaccines.
Immunology professor Danny Altmann, a co-author who wrote the Science alongside Rosemary Boyton, Professor of Immunology and Respiratory Medicine, discussed their research findings in a recent editorial. They noted that contrary to a popular belief that vaccines and previous infections provide “a wall of immunity”, nations are instead experiencing “wave after wave of new cases”.
In the study, Professor Altmann explains how they followed people who had triple vaxxing and those who had breakthrough infections during the first waves of Omicron.
“This allows us to examine whether Omicron was, as some had hoped, a benign natural booster of our Covid immunity,” he wrote in The Guardian. “It turns out that’s not the case.”
“Most people – even triply vaccinated – had 20 times less neutralizing antibody response against Omicron than against the original ‘Wuhan’ strain,” Altmann said, noting that, crucially, “Omicron infection was a poor immunity booster against Omicron infections”.
“It’s a kind of stealth virus that goes unnoticed,” he said, pointing out that “even after having Omicron, we are not well protected against new infections.”
Dr. Altmann’s research appears to confirm other recent studies that have been published in recent weeks that warn of the ability of new subvariants to evade protection from previous immune-boosting precautions; namely vaccination and natural immunity.
Research published in Nature from Columbia University, a study that has not yet been peer-reviewed, suggests that BA.4 and BA.5 are four times more resistant to vaccine antibodies than BA.2, a subvariant that is became the dominant strain in the United States in April, replacing the original strain that had propelled the winter surge across the country.
Although experts believe these current strains will likely fuel new waves, they noted that vaccines will provide partial immunity and can still protect against potentially more serious infections.
“Our data suggest that these new Omicron subvariants are likely to lead to outbreaks of infections in populations with high levels of vaccine immunity as well as natural BA1 and BA2 immunity,” Dr. Dan Barouch told CNN. “It is likely that vaccine immunity will still provide substantial protection against severe disease with BA4 and BA5.”
Dr Barouch was one of the co-authors of a separate article, published with the New England Journal of Medicinewhich found that there was a three-fold reduction in vaccine neutralizing antibodies and infection against BA.4 and BA.5, which was significantly lower than BA.1 and BA2.
For this reason, the vaccines that many have received over the past 18 months will likely need not just a boost, but an update.
The Federal Drug Administration recommended last week that the makers of the Covid-19 vaccines, namely Pfizer and Moderna, begin modifying what they currently offer so that their booster shots can more precisely target the BA.4 and BA variants. .5 and estimated that these injections could be available as early as mid-autumn.