How long will vaccine protection last?Science certainly can’t say

Protection from the coronavirus vaccine is expected to diminish, No one knows when. The first wave of people vaccinated last winter will be soon this fall. Many people predict Covid boosters will soon be participating in the annual flu shot.

Ideally, anyone worried about the decline in vaccine protection can be tested for antibodies that fight Covid, the primary defense against the virus. But it’s not that simple, as cancer patients and others with impaired immune systems are learning.

Craig Bunnell, Chief Medical Officer at the Dana-Farber Cancer Institute, said: “The bad news is that we still don’t know how to interpret the results.”

The knowledge-testing gap increases the likelihood that the anxiety of wondering if vaccinated people are still protected will increase in the coming months. Anxiety can discourage public adventure. As a result, it could be a new impediment to the recovery of the global economy.

Scientists figure out The so-called correlation of protection against Covid. In other words, which test result guarantees immunity.

New data Harvard University School of Public Health epidemiologist Michael Mina said it was published almost weekly to help researchers understand which immune signs reflect protection. However, he said it is likely that it will take several months before the situation becomes clear.

Also, it is not yet known how long the vaccine will generally last. They are so new that I haven’t had time to follow the recipient for so long. evidence Suggests sustained antibody protection At least 6 monthsBut beyond that it remains unclear.

This is a type of post-vaccination problem that people with impaired immune systems are already familiar with.

People who are “immunized” make up estimates 3% of the population, Including people For Blood Cancer-Over 1 million survivors In the United States, the same is true for people with autoimmune diseases, HIV, and transplanted organs that require rejection drugs.

Michele Nadeem-Baker embodies their dilemma. She has been fully vaccinated and is rubbing to return completely to the world after more than a year as a self-proclaimed “bubble woman” who just leaves home and walks in the hills of Boston’s Charlestown district.

New guidance from the US Centers for Disease Control and Prevention allows other Bostonians to strip off their masks outdoors and resume almost normal life, but for her it’s pretty much the same. Her weak immune system means that vaccination does not guarantee protection, and she believes there is no end to evacuating to the right place.

“I’m told I can’t go back to life,” she said. “How do I know for sure if I can do it? The only way to do that is to get scientific evidence.”

So last month, Nadeem-Baker, an advocate of leukemia and cancer patients, asked for a test for coronavirus antibodies. Result: More frustration. She had some illness-fighting protein, but her doctor couldn’t confidently interpret her score, so she had to keep acting as if she didn’t have it. I told her there was.

In the body Complex array of defenses Antibodies act like scouts against bacteria, identifying and targeting intruders. They have a strong backup force. “Memory” B cells and T cells That lamp Until Fight the enemies they recognize. Therefore, antibody testing is far from the big picture.

“John Doe’s antibody levels are 14, 40, 400, and 4,000,” said Mina of Harvard University, an authority on testing and antibodies. “These numbers have no meaning.”

To establish sufficient antibody levels for strong protection, he said, it would take time to test many people to determine when the virus could break through.

Again, the patient may not be measuring a particular antibody, but is protected from other elements of the immune system, such as B cells and T cells. Alternatively, it may turn out that the particular antibody being measured isn’t really the key to killing the virus, Mina added-it’s stuck all over the enemy’s body, but on the nose and Something like a hundred-bit duct tape that is not attached to the mouth. Not fatal.

Not a good sign

More than 2,000 blood cancer patients, including Nadeem-Baker sign up Free antibody testing as part of a study by the Leukemia & Lymphoma Society is described by Lee Greenberger, chief scientific officer of a national nonprofit organization.

“The research is done as quickly as possible, so we understand the magnitude of the problem and find solutions on how to protect these patients,” he said.

According to Greenberger, early findings of cancer patients show how dramatically the Covid antibody response varies by individual and condition. For some types of cancer, “40 or 50% of patients do not make antibodies,” he said. “In another blood cancer, everyone makes antibodies.”

Among healthy volunteers, he said, almost everything gets strong antibody test results, but it’s still unclear as the other arms of the immune system can provide protection. What Does Even a Zero-Antibody Test Result Mean?, Except for “It’s a warning sign”.

The results remain very vague, so the CDC explicitly To tell “Antibody testing to assess immunity is not recommended” after vaccination of people with immunity problems.

The same is true for Dana-Farber Precautions “Unfortunately, there is no reliable way to know if the vaccine worked,” said a cancer patient.

“As you gain a better understanding of the test results, what they mean, and how to respond to them, you may find that testing helps,” he said. “Until then, it is advisable to be vaccinated and continue to take precautions to reduce the risk of exposure.”

Also, it has not been decided yet. How the general public reacts when the test appears to be weakened and the test is inconclusive, especially when epidemiologists say, when a new outbreak occurs.

John Rico, a Penn Wharton budget model analyzing the economic impact of vaccines, said new outbreaks are likely to be localized, limiting the economic impact in countries with high vaccine intake. He said it was likely. But this outlook emphasizes one consistent finding, he said. “The dollars spent on all kinds of vaccine research at this point have a very high return on investment.”

“Don’t believe them”

Research on new tools for measuring immunity is progressing rapidly, said Mina of Harvard University. His lab is working on them, testing tens of thousands of antibodies a week.

He envisions a mass test to monitor immunity to Covid and other viruses, both for personal awareness and public health. But to do that, antibody testing would have to be much cheaper than the current $ 120 or so, he said.

There are some tests on the market, but “if someone is telling you that they are giving you an idea of ​​how protected you are, I don’t believe them,” he said. Told.

Weaver HealthCambridge, Massachusetts-based start-ups are one of those ready to change. Applies to an emergency use authorization for a 10-minute antibody test at home.