New research from France adds to the evidence that widely used COVID-19 vaccines still provide strong protection against the coronavirus mutations that are spreading rapidly around the world and are now the most widely used type in the United States.
The delta variant is increasing among populations with low vaccination rates. On Thursday, Dr. Rochelle Walinsky, director of the US Centers for Disease Control and Prevention, said this leads to two “facts” – areas of America that are highly immunized are returning to normal while hospital admissions are rising elsewhere.
“This rapid rise is alarming,” she said.
A few weeks ago, the delta variant accounted for more than a quarter of new cases in the US, but now it accounts for just over 50 percent — and in some places, like parts of the Midwest, as much as 80 percent.
On Thursday, researchers from France’s Pasteur Institute reported new evidence that full vaccination is critical.
In lab tests, the team found that blood from several dozen people who took their first dose of the Pfizer-BioNtech or AstraZeneca-Oxford vaccine “almost prevented” the delta variant. It was reported in Nature magazine. But weeks after getting their second dose, nearly all of the researchers had what the researchers considered an immune booster strong enough to neutralize the delta variant — even if it was less effective than previous versions of the virus.
The French researchers also tested unvaccinated people who survived a bout of coronavirus, finding that their antibodies were four times less effective against the new mutation. The study found that a single vaccine dose significantly boosted antibody levels — resulting in mutual protection against the delta variant and two other mutants. This supports public health recommendations that COVID-19 survivors be vaccinated rather than relying on natural immunity.
Laboratory experiments add to the real-world data that delta variant mutations do not bypass the most commonly used vaccines in Western countries, but they confirm that it is necessary to immunize more of the world before the virus can develop further.
Researchers in Britain found that two doses of the Pfizer vaccine, for example, protected 96 percent of hospitalizations with the delta variant and 88 percent effective against symptomatic infections. This finding was echoed by Canadian researchers last weekend, while a report from Israel suggested that protection against mild delta infections may have fallen to 64 percent.
Whether a fully vaccinated person still needs to wear masks in places where the delta variant is elevated is an increasing question. In the United States, the Centers for Disease Control and Prevention (CDC) stresses that fully vaccinated people do not need to. Even before the delta variant appeared, vaccines were not perfect, but the best evidence suggests that if vaccinated people contracted the coronavirus, they would have milder cases.
“Let me stress that if you are vaccinated, you have a very high degree of protection,” Dr. Anthony Fauci, the US government’s top infectious disease expert, said Thursday.
Pfizer is seeking FDA authorization for a third-dose booster جرعة
Also on Thursday, Pfizer said it plans to obtain US clearance for a third dose of its COVID-19 vaccine.
In general, antibodies naturally diminish over time, so studies are underway to determine if and when COVID boosters are needed.
Early data from the company’s booster study suggests people’s antibody levels jump five to 10 times after a third dose, compared to the second dose months earlier, Dr. Michael Dolstein, chief scientific officer of Pfizer, told The Associated Press.
In August, Pfizer plans to ask the U.S. Food and Drug Administration for emergency authorization for a third dose, he said.
But the FDA’s permission would be just a first step — it won’t automatically mean Americans get boosters, warned Dr. William Schaffner, a vaccine expert at Vanderbilt University Medical Center. Public health authorities will have to decide if it is really needed, especially since millions of people remain without protection because they have not been vaccinated.
Case rates in the United States have been on the rise for weeks, and the rate of hospitalizations is beginning to rise, seven percent above the previous seven-day average, Walinsky of the US Centers for Disease Control and Prevention told reporters Thursday. However, deaths remain low on average, which some experts believe is at least partly due to the higher vaccination rates in people 65 or older, who are among the most vulnerable to serious disease.