Pfizer-BioNTech և Moderna vaccines, which are designed to fight the coronavirus epidemic, are quite effective in preventing infections in the real world, according to a federal study released Monday that provides protection for front-line workers in the United States.
A study of some 4,000 health workers, police, firefighters and other key staff found that the Centers for Disease Control and Prevention found that vaccines reduced the risk of infection by 80% after a single shot. After the second dose, protection increased to 90%. The findings are in line with the results of clinical trials in highly effective studies in Israel and the United Kingdom, as well as in preliminary studies of health workers at the University of Texas in Southern California.
According to experts, the CDC report is significant because it analyzes the extent to which vaccines work in a diverse group of primary working-age adults, whose work makes them more likely to be exposed to the virus.
The workers came from eight locations in six states: Arizona, Florida, Minnesota, Oregon, Texas and Utah. They were vaccinated from mid-December, when doses first became available, until mid-March, a 13-week period that included a deadly winter wave that killed more than 3,000 people daily since January. The study was one of the first to assess the effectiveness of the vaccine in participants against infection, rather than just monitoring symptomatic cases, including infections that did not cause symptoms, according to the CDC.
Of the 2,479 fully vaccinated people, only three confirmed the infections. Eight infections were reported in 477 people who received a single dose.
For comparison, out of 994 unvaccinated people, 161 were infected.
Death is reported.
CDC Director Rochelle Valensky said the study showed that national vaccination efforts were working.
“Coronavirus-enabled vaccines” provide early, substantial protection against infection for our country’s health care personnel, first responders, and other frontline personnel, “he said. “These discoveries should inspire hope for the millions of Americans who receive the daily coronavirus vaccine, those who will be able to bend their legs and be vaccinated in the coming weeks.” “Authorized vaccines are the main tool to help end this devastating epidemic.”
The study continues, և Researchers will share more details about partially or completely vaccinated human infections known as “leading infections”. Researchers are also examining whether people who are infected with the vaccine may have less serious or more unpleasant illnesses and whether they shed the virus less often.
Infectious disease և vaccine experts say the latest data are very promising.
“Surprising is not possible, but it is incredibly encouraging,” said Paul A. Ofit, a vaccine expert at Philadelphia Children’s Hospital who helps review vaccine safety and efficacy as an Food and Drug Administration external consultant, was not involved in the CDC study. “Vaccination is one reason.”
Clinical trials of their coronavirus vaccines were conducted by drug companies in 2020, when the United States did not have the largest wave of COVID-19 cases, says Monica Gandhi, an infectious disease specialist at the University of California, San Francisco.
“What we really want to do is test these vaccines in the real world to see how well they work,” said Gandhi, who was not involved in the CDC study. He said the study was conducted during one of the “most terrifying, terrifying waves” in the United States, describing it as a potential stress test for vaccines. The results, he said, show how “really incredible news is how safe you can be after vaccination.”
Pfizer-BioNTech և Moderna vaccines, which require two doses, were more than 90% effective in preventing symptomatic COVID-19 disease in clinical trials before the vaccines received emergency approval from the FDA in December. The Pfizer-BioNTech vaccine requires special treatment է it must be stored in special freezers for a long time, especially at cold temperatures.
“There is no guarantee that vaccines will do the same in the real world, where there has been a lot of concern about refrigerated temperatures,” said Mark G., a CDC epidemiologist and lead author of the report. Thompson. Clinical trials have been performed in a large number of elderly people, but the CDC study focused mainly on the ability of working-age adults to get vaccinated against the infection, regardless of whether symptoms developed.
“The big drawback here is that 14 days after receiving their two doses. “Vaccines, these front-line workers are 90% less likely to become infected with the COVID-19 virus,” Thompson said.
Reducing the risk of transmitting the infection, which may occur a few days before the onset of symptoms, is especially important for health care professionals and other key personnel who may not be aware that they are infected.
About 72% of the participants were between 18 and 49 years old, and the majority were women. Most of the participants were white and healthy, without chronic medical conditions. About half were health care providers. 21% were firefighters, police and emergency medical technicians. Nearly a quarter were teachers, delivery workers, and other potential staff who needed to communicate with the public or employees three feet away.
About 63% of participants received the Pfizer-BioNTech vaccine, and 30% received the Moderna shot. Five people received the Johnson & Johnson vaccine. Researchers are trying to determine what vaccine the other vaccines were given. Many received the first dose in the last two weeks of December.
Participants had nasal swabs for 13 weeks during the week, regardless of whether they had any symptoms. If they showed symptoms of COVID-19, such as fever, chills, coughing, shortness of breath, or a change in smell or taste, they collected extra nasal swabs. All samples were sent to a laboratory in Whiskey, Marshfield.
Thompson says the study was the most challenging and ambitious for the design, which has carried out more than 30 years of field research. It was difficult to gather thousands of participants from all over the country, of different backgrounds, in the context of distrust of broad skepticism և science և research. Researchers have never asked people to collect their own nose swabs, ship saliva samples, and it was not clear at the outset whether busy adults working on the front lines would respond consistently to these tasks.
“But the participants have been very dedicated. To date, on average, 80% to 100% of participants complete these tasks each week,” Thompson wrote.
The CDC also had to negotiate with FedEx և UPS to allow thousands of samples to be delivered for testing.
The study did not provide an assessment of the benefits of vaccines against viral versions circulating in the United States. Thompson, who is leading the assessment of the effectiveness of the CDC coronavirus vaccine, says the agency will have more to say in about a month when scientists complete the genetic characterization of the collected virus samples.
During the study, researchers will also analyze the effectiveness of specific coronavirus vaccines and their effectiveness in preventing symptomatic infections or severe outcomes such as hospitalization.
Despite the strong protection given by the vaccine, two weeks after the first dose, scientists are still trying to find out how long it takes for one to be fully vaccinated against the disease, whether the two doses provide longer protection than one dose.
Limitations of the study include the small number of confirmed infections ինքն self-sampling և delayed laboratory loads that may reduce virus detection և overestimation of vaccine efficacy.
The latest results come as President Biden set a new goal of managing 200 million shares in his first 100 days in office on April 30. The nation is ready to achieve the revised goal as the seven-day average of daily vaccinations. exceeds 2.5 million.
But infectious disease experts are concerned that the pace needs to be accelerated to achieve the high level of immunity needed to slow the virus, especially as more transmissible versions spread across the country. To reach the required level of protection, about 80% of the population must be immunized, which means that about 260 million people must be vaccinated. It will require 3 to 3.5 million shots every day until April 30.