The Union Ministry of Health and Family Welfare, in a show of credulous buying of China-influenced World Health Organisation’s (WHO) statements, announced on 22 June that the variant of the Sars-Cov-2 — now referred to as “Delta Plus” — found at present in a small number of people was of concern and advised states to ‘redouble’ containment and testing efforts.
The variant in question is part of the lineage of the Delta variant, which is slowly turning out to be significantly more dangerous than the virus that first came out of Wuhan, the media, which never showed as much zeal in stressing the Chinese origin of the virus in 2020, is now repeatedly saying.
Informally called the Delta Plus and scientifically classified as the AY.1, the further evolution of the Delta variant includes a mutation (K417N) that separately has shown attributes that could hamper the efficacy of vaccines. The announcement came within hours of the Union health secretary first suggesting the variant may not have turned into a major cause for concern yet.
The mutated virus that sneaked into India from the UK, Delta is one of several “variants of concern,” as designated by the Centers for Disease Control and Prevention (CDC) and the WHO. It has spread rapidly through the UK and India.
Delta in US
The appearance of the mutated virus in the United States is not surprising. And with vaccinations ticking up and Covid-19 case numbers falling, it’s unclear how much of a problem Delta will cause here. Still, its swift rise has prompted concerns that it might jeopardise the nation’s progress in beating back the pandemic.
“The Delta variant is currently the greatest threat in the US to our attempt to eliminate Covid-19,” Dr Anthony Fauci, the nation’s leading infectious disease expert, albeit discredited now, said at the briefing. The good news, he said, is that the vaccines authorized in the US work against the variant. “We have the tools,” he said. “So let’s use them and crush the outbreak.”
Delta, formerly known as B.1.617.2, is believed to be the most transmissible variant yet, spreading more easily than both the original strain of the virus and the Alpha variant first identified in Britain. Public health officials there have said that Delta could be 50% more contagious than Alpha, although estimates of its infectiousness vary.
Other evidence suggests that the variant may partially evade the antibodies made by the body after a coronavirus infection or vaccination. And the variant may render certain monoclonal antibody treatments less effective, the CDC notes.
Delta may also cause more severe illness. A recent Scottish study, for instance, found that people infected by the Delta variant were roughly twice as likely to be hospitalized than those infected with Alpha. But uncertainties remain, scientists said.
“The severe disease piece I think is the one question that really hasn’t been answered yet,” said Dr. Michael Osterholm, director of the Center for Infectious Disease Research and Policy at the University of Minnesota.
Delta has been reported in 80 countries. It is now the most common variant in India and Britain, where it accounts for more than 90% of cases.
Delta was identified in the US first in March. Although Alpha remains the most prevalent variant there, Delta has spread quickly. In early April, Delta represented just 0.1% of cases in the US, according to the CDC. By early May, Delta accounted for 1.3% of cases, and by early June, that figure had jumped to 9.5%. A few days ago, the estimate reached 20.6%, Fauci said at the briefing.
The Delta variant is unlikely to pose much risk to people who have been fully vaccinated, experts said.
“If you’re fully vaccinated, I would largely not worry about it,” said Dr Ashish K. Jha, dean of the Brown University School of Public Health.
According to one recent study, the Pfizer-BioNTech vaccine was 88% effective at protecting against symptomatic disease caused by Delta, compared with its 93% effectiveness against the Alpha variant. But a single dose of the vaccine was just 33% effective against Delta, the study found.
“Fully immunised individuals should do well with this new phase of the epidemic,” said Dr Peter Hotez, dean of the National School of Tropical Medicine at Baylor College of Medicine. “However, the protection offered by a single dose appears low, and of course if you are not at all vaccinated, consider yourself at high risk.”
Delta is likely to infect “large numbers” of unvaccinated people, he said.
The pandemic is waning in the US, with cases, hospitalizations and deaths declining. The seven-day case average, roughly 10,350 a day, is the lowest since March 2020, Dr Rochelle Walensky, director of the CDC, said at the briefing Tuesday. “These numbers demonstrate the extraordinary progress we’ve made against a formidable foe,” she said.
So while Delta may account for an increasing percentage of cases, it is not yet clear whether it will drive the total number of cases higher.
“I think we are not going to see another big, national surge in the US, because we have enough vaccination to prevent that,” Osterholm said.
Still, vaccination rates have been highly uneven and are lower in certain states and demographic groups. Delta could fuel outbreaks in the South, where vaccinations lag, or among young people, who are less likely to be vaccinated than their elders.
“In places where there’s still a lot of susceptibility to the virus, it opens a window for cases to start going up again,” said Justin Lessler, an infectious disease public health researcher at Johns Hopkins University. “But even in those states, and certainly nationally, we’re probably not getting back to the numbers we were seeing last winter.”
Still, he said, it could prolong our path out of the pandemic. “It continues the doldrums,” he said.
Does vaccination help?
Get vaccinated. If you’re already vaccinated, encourage your family, friends and neighbors to get vaccinated. Vaccination is likely to slow the spread of all the variants and reduce the odds that new, even more dangerous variants emerge.
“I encourage people who are vaccinated to trust in the vaccines but be cognizant that new variants will continue to occur where transmission exists,” said Saskia Popescu, an infectious disease public health researcher at George Mason University. “So it’s really about ensuring local, national and global vaccination.”
Covid-19 vaccines made by AstraZeneca and the Pfizer-BioNTech alliance remain broadly effective against Delta and Kappa variants of the Covid-19 causing virus, which were first identified in India, according to a scientific study, underpinning a continued push to deliver the shots.
The study by Oxford University researchers, published in the journal Cell, investigated the ability of antibodies in the blood from people, who were vaccinated with the two-shot regimens, to neutralize the highly contagious Delta and Kappa variants, a statement said.
“There is no evidence of widespread escape suggesting that the current generation of vaccines will provide protection against the B.1.617 lineage,” the paper said, referring to the Delta and Kappa variants by a commonly used code.
However, the concentration of neutralising antibodies in the blood was somewhat reduced, which may lead to some breakthrough infections, they cautioned.
Last week, an analysis by the Public Health England (PHE) showed that vaccines made by Pfizer Inc and AstraZeneca offer high protection of more than 90% against hospitalization from the Delta variant.
“We are encouraged to see the non-clinical results published from Oxford and these data, alongside the recent early real-world analysis from Public Health England, provide us with a positive indication that our vaccine can have significant impact against the Delta variant,” AstraZeneca executive Mene Pangalos said in a separate statement.
The Delta variant is becoming the globally dominant version of the disease, the WHO’s chief scientist said on Friday.
The Oxford researchers also analysed reinfection patterns in people who had previously had Covid-19. The risk of reinfection with the Delta variant appeared particularly high in individuals previously infected by the Beta and Gamma lineages that emerged in South Africa and Brazil, respectively.
By contrast, previous infection with the Alpha, or B117, variant first detected in Britain, conferred “reasonable” cross-protection against all variants of concern, lending itself as a template that next-generation vaccines could be molded on.
“B117 might be a candidate for new variant vaccines to provide the broadest protection,” the researchers said.