The variant of the delta coronavirus, formerly known as B.1.617.2, is triggering epidemics in vulnerable, mostly unvaccinated areas around the world.
It has become the most dominant version of the virus in the United States, now accounting for around 83% of cases analyzed. Almost two months ago, the delta variant represented only 6% of sequenced cases.
The seven-day national average of new coronavirus cases has jumped by about 53%, with hospitalizations (up 32%) and deaths (up 19%) also rising worryingly, according to a Thursday from the House White COVID-19 Report.
Evidence shows that the variant is around 60% more contagious than previous versions of the virus, although estimates vary.
Doctors and scientists say the public’s greatest defense against the virus and its variants is vaccination. But how well do COVID-19 injections prevent serious illnesses caused by the delta variant?
Here is the latest data on each of the three vaccines authorized for emergency use in the United States.
A study by Public Health England found that three weeks after a dose, the Pfizer-BioNTech vaccine was 33% effective against symptomatic COVID-19 caused by the delta variant. Two weeks after the second dose, which is recommended for full protection, it was 88% effective.
However, data from Israel shows that the effectiveness of the Pfizer vaccine has fallen to 64% in preventing infections and symptomatic illnesses as the country treats the delta variant, which is the dominant version of the virus there.
Still, the shot remains 93% effective against severe COVID-19 and hospitalization.
The results of a lab study published in June showed that the Moderna COVID-19 vaccine appears effective against the delta variant, as well as other variants tested, with just a “modest reduction” in antibody levels compared to to the original strain.
Analysis of blood samples from eight people taken a week after their second dose in the Phase 1 clinical trial found that antibody levels were approximately two times lower when compared to the delta variant compared to the original coronavirus strain.
But experts say it’s important to keep in mind that antibodies aren’t the only defenses your immune system has to fight the coronavirus. There are other components such as memory B cells and T cells that also play a major role in destroying viruses, although these players are less understood in the context of COVID-19.
Johnson & Johnson vaccine
The single-dose Johnson & Johnson COVID-19 vaccine also boosted antibody activity against the delta variant, and “to an even higher level” compared to that of the beta variant first identified in South Africa.
Overall, it was 85% effective against serious / critical illness and protected against hospitalization and death.
Although a new, unpaired peer-reviewed study published on Monday found that the delta variant, along with a list of other variants spreading across the world, resulted in a 3.2 to 4.9-fold decrease in level of antibodies produced after vaccination with the Johnson & Johnson shot compared to D614G, an ancient strain of coronavirus.
The researchers say their findings highlight the benefits of a potential second injection after a dose of the Johnson & Johnson vaccine to “increase protection against variants.”
“The message we wanted to get across was not that people shouldn’t get the J. & J vaccine, but we hope that in the future it will be boosted either with another dose of J. & J or with a boost with Pfizer or Moderna, “Nathaniel Landau, a virologist at the Grossman School of Medicine at New York University, who led the study, told the New York Times.
What about the booster injections?
All of the companies behind COVID-19 vaccines in the United States have said they are working on a different version of their vaccine to act as a booster for prolonged or more effective protection.
But federal health officials say they’re not needed – at least not yet.
In a rare joint statement released on July 8, the Centers for Disease Control and Prevention and the Food and Drug Administration said fully vaccinated Americans did not need a coronavirus booster vaccine “yet.”
Their announcement came shortly after Pfizer and BioNTech said they were developing an updated version of their vaccine designed to specifically target the delta variant and that they planned to begin clinical trials in August if they received any. “Regulatory approvals”.
Dr Anthony Fauci, chief medical adviser to the White House, told CNN that COVID-19 booster injections could “theoretically” help protect vulnerable people, but the CDC and FDA recommendations are based on data and information currently available. But that “doesn’t mean we stop there,” he said.
“Studies are underway right now, underway as we speak, on the feasibility of whether and when we should stimulate people,” Fauci told the outlet. “So it’s not something that we say ‘no we don’t need a push right now, the story is over forever.’ No, there is a lot of work going on. course to look at this in real time to see if we might need a boost.
While COVID-19 vaccines in the United States are now sufficiently effective against the delta variant, experts say the more the coronavirus jumps from person to person, the more likely it is to mutate into a version that could potentially day escape the fire ‘defenses.
The World Health Organization has suggested that fully vaccinated people always wear face masks when possible, citing the increased transmissibility of the delta variant and the risk of severe COVID-19. It has been found in at least 98 countries as of July 2.