Study Reveals Waning Efficacy of Covid-19 Vaccines

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  • Experts warn of waning vaccine immunity, a lapse in precautions, or the rise of a highly contagious Delta variant. 
  • Health officials outlined plans that people get booster shots eight months after receiving their second dose. 
  • Scientists were doubtful of the administration’s new initiative on additional doses.

The C.D.C. revealed three studies that federal authorities said offered evidence that booster injections of the Pfizer-BioNTech and Moderna coronavirus vaccines will be required in the coming months, reports The New York Times.

Outcome Of the Study

However, several experts argued the new Study did not support prescribing booster shots for all Americans. 

Experts warn of waning vaccine immunity, a lapse in precautions, or the rise of a highly contagious Delta variant. Dr. Vivek Murthy, the surgeon general, said, “We are concerned that this pattern of decline we are seeing will continue in the months ahead, which could lead to reduced protection against severe disease, hospitalization, and death.”

Some scientists were skeptical of the administration’s new initiative. “These data support giving additional doses of vaccine to highly immunocompromised persons and nursing home residents, not to the general public,” said Dr. Céline Gounder, an infectious disease specialist at Bellevue Hospital Center and a former adviser on the pandemic to the administration.

People who received the Johnson & Johnson vaccine may also require additional doses of the vaccine. Health officials outlined plans that people get booster shots eight months after receiving their second dose.

The Need for Boosters

Boosters would only be warranted if the vaccines were failing to prevent hospitalizations with Covid-19, she said.

“Feeling sick like a dog and laid up in bed, but not in the hospital with severe Covid, is not a good enough reason” for a campaign of booster shots, Dr. Gounder said. “We’ll be better protected by vaccinating the unvaccinated here and around the world.”

There’s no question whether a third dose would be helpful for those who didn’t respond to the two first doses with a strong immune response, says Bill Hanage, a Harvard T.H. Chan School of Public Health epidemiologist. He also warned: “A third shot will add to skepticism among people yet to receive one dose that the vaccines help them.”

The new trials show that immunizations’ efficacy against all infections is around 55 percent, with symptomatic infections 80 percent and hospitalizations 90 percent or higher.

Vaccines’ Impact

  •  Vaccination effectiveness dropped the most among people aged 18 to 49
  • Data from Israel suggests that infection immunity in vaccinated persons aged 65 and up has diminished.

The third Study from the C.D.C. found that the vaccines showed 90 percent effectiveness against hospitalizations in the country, “which is excellent,” Dr. Gounder noted.

The vaccines were less protective against hospitalization in immunocompromised people. “But not all immunocompromised persons will respond to an additional dose of vaccine,” Dr. Gounder noted.

As more unvaccinated persons become infected, recover, and build natural immunity, the vaccines may appear to lose relative effectiveness statistically. If the goal is to avoid infection, Dr. Gounder suggests developing a nasal spray vaccination booster to produce immunity in the nose and throat, where the virus enters the body.

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Source: The New York Times