in

CDC does not publish data to judge risk of post-vaccination infections (Analysis)

New York will pay those who get vaccinated against covid-19 0:37

. – Federal health officials surprised almost everyone this week when they announced a change to the guidance for fully vaccinated people, saying most should go back to wearing masks indoors.

The US Centers for Disease Control and Prevention (CDC) also said that everyone should wear masks in school: students, teachers, staff and visitors.

CDC Director Dr. Rochelle Walensky said the new data had convinced her that the delta variant was “behaving uniquely.” He said the evidence indicates that fully vaccinated people who have infections involving delta may be just as likely to transmit the virus to other people as unvaccinated people.

Also, he said, people living in areas of high or sustained transmission should start wearing masks in public again, even if they are vaccinated, because of the increased risk of becoming infected when more viruses circulate.

But she did not present the data, and the CDC website still indicates that only 5,914 people have become seriously ill from covid or have died despite being vaccinated.

This, when the CDC issued a health alert and held a rare briefing on Tuesday to warn that the delta variant was spreading faster than previous variants, and urging people to go back to mask wearing and get vaccinated.

If the CDC had done more to report on post-vaccination infections, the change in the mask wear guide may not have taken the country so much by surprise.

Instead, the seemingly sudden adjustment on the guide looked like a 180-degree turn.

And he questions President Joe Biden’s repeated promises that his administration would not only follow the science, but would be transparent and open about it.

No vaccine is 100% effective, and studies show that while the three vaccines licensed in the U.S. protect well against serious illness and disease, they are less effective at preventing any type of infection, including a mild case of Covid-19 or an asymptomatic infection.

The CDC has tracked serious infections that required hospitalization and deaths among fully vaccinated people. But it is not releasing that data in a timely manner and has stopped national monitoring of mild and asymptomatic infections.

That makes it difficult to know whether fully vaccinated people are, in fact, less likely to pass the infection on to others. It is difficult to say whether people infected with the delta variant despite having been vaccinated are more likely to infect others.

And it is difficult to be sure that the virus is not infecting millions of fully vaccinated people and perhaps evolving in their bodies under pressure from a vaccinated immune system, a scenario that is unlikely but could theoretically lead to new ones. variants impervious to the vaccine.

“I think it’s important to track symptomatic post-vaccination infections. It’s important to track hospitalizations and deaths, but if you don’t track all symptoms, from an epidemiological point of view, you don’t know the frequency or severity of those symptomatic infections.” David Holtgrave, dean of the School of Public Health at the University of Albany, State University of New York, told CNN.

“Plus, you miss the opportunity to follow up with a sample of people with symptomatic post-vaccination infections to see if they develop long-lasting symptoms. I don’t think we have a good handle on that. We could use better data.”

This lack of data could also have the effect of reducing confidence in the vaccine, Holtgrave said.

“If you want to be able to assure the nation that post-vaccination infections are rare, and I think symptomatic post-vaccination infections are relatively rare even in the delta era, you have to be able to say ‘we went out and looked for those infections a lot and we didn’t find many, and when we did, they weren’t that bad, ‘”Holtgrave said.

“You’re only as reassuring as the extent to which you went out and looked.”

The CDC did this by looking for rare side effects from covid-19 vaccines, including a rare blood-clotting condition related to the Johnson & Johnson vaccine and an unusual inflammatory response that affects the heart called myocarditis related to the Pfizer and vaccine vaccines. Modern

Why should I continue to use the mask if I am already vaccinated 2:55

CDC promises more data

Walensky promised that they would bring more data.

“In the next few days, you will see the information published about the science that motivated this change,” he told CNN’s “New Day” on Wednesday.

He made a similar promise on Tuesday.

“We are collecting passive reporting data on hospitalized and deceased people, but we recognize that epidemiologically that will not give us the best information regarding post-vaccination infection rates, because passive data collection is generally not reported,” he said. Walensky to reporters on a conference call.

“To counteract that, we have been collecting data across more than 20 cohorts of people. These include tens of thousands of people we follow across the country, and include healthcare workers, essential workers, health care centers, long-term, and in some of these cohorts, we are collecting CRP (test) data from each person in them weekly, “Walensky added.

“So we are absolutely studying and evaluating post-vaccination infections at many different sites, many different people, across the country. We are looking at that data weekly or biweekly and will be reporting on it soon.”

Following people and testing them weekly, whether they show symptoms or not, is the best way to track asymptomatic infections.

Having the number of mild, asymptomatic post-vaccination infections would also help people better judge their risk of developing a serious infection despite having been vaccinated, said Jennifer Nuzzo, an epidemiologist and principal investigator at the Johns Hopkins Center for Health Security.

“The number is reported, but not having the denominator makes it more difficult to put it in context,” Nuzzo told CNN. It might be reassuring to know that while there are many post-vaccination infections, only a very small percentage of them are serious enough to cause concern.

“There is a public fascination for people who got COVID despite being vaccinated and I think we need a way to respond to that,” Nuzzo added.

It wouldn’t even be necessary to count all the cases, he said. A systematic sample, like the cohorts Walensky described, might be sufficient.

Dr. Tom Frieden, former director of the CDC and now CEO of the health advocacy group Resolve to Save Lives, has a similar point of view.

“It is neither necessary nor prudent for our public health systems to attempt to track each and every post-vaccination case that only causes or does not cause even mild symptoms,” he wrote in a recent opinion piece for CNN.

“There are just going to be too many, and monitoring for illnesses that are no worse than a cold has little benefit. Instead, it makes sense, as is being done, to conduct special studies of all post-vaccination infections as part of specific studies based on vaccination. population, and also to try to track all serious covid diseases after vaccination, “he added.

“This should give us much better information on who is at higher risk for severe COVID disease after vaccination and could lead to different dosing recommendations for some groups.”

Having more data on post-vaccination infections could also help epidemiologists better track changes in how the virus spreads, Nuzzo said.

“I’d like to see more footage to see the chains of transmission and the clusters and where people get sick,” he said.

Give Ammo to Vaccine Resistance

Better information on post-vaccination infections would also support the case for vaccinating the entire population to provide herd immunity.

The lack of data to support the guideline change gave Arizona Governor Doug Ducey and other Republican governors an opportunity to say that the guideline change would lower confidence in the vaccine and double the refusal of citizens to get vaccinated and used. More expensive.

It also creates the impression that the new guide was issued for political reasons.

“Do you really think the CDC has changed the mask guide for vaccinated adults, to use Dr. Walensky’s words, because … a vaccinated person can transmit the virus to an unvaccinated person? No,” he told CNN Dr. Jonathan Reiner, professor of medicine and surgery at George Washington University, Tuesday night.

“They changed the guideline to do the right thing, which was basically to force unvaccinated people to get vaccinated.”

Some people who resist vaccination say it is a personal choice, affecting only themselves.

Dr. Paul Offit disagrees.

“There’s an old study on measles transmission between 1999 and 2000. It’s going to seem contradictory what they found, but if you think about it, it makes sense,” said Offit, FDA’s vaccine adviser and director of the Center for Vaccine Education. at Children’s Hospital of Philadelphia, to CNN’s Jim Acosta last week.

“Obviously, you were less likely to get measles if you were vaccinated living in a highly vaccinated community. But you were actually more likely to get measles if you were vaccinated living in a highly unvaccinated community than if you were not vaccinated but living in a highly vaccinated community. “Offit said.

That’s in line with what the CDC said Tuesday. CDC could also benefit by showing your sources.

Haney retains WBC lightweight world title

‘Flag Day’ trailer, with Sean Penn and Dylan Penn