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Are you wondering if the vaccine worked?Get the right test at the right time

Many are wondering now that tens of millions of Americans have been vaccinated against the coronavirus. Do you have enough antibodies to keep me safe?

For most people, the answer is yes. It does not stop hordes from being pushed into the local doc-in-a-box for antibody testing. However, to get a reliable answer from the tests, vaccinated people need to take certain types of tests at the right time.

Take the test too early or rely on someone looking for the wrong antibody. Array of test confusion Currently available — and you may believe that you are still vulnerable even when you are not.

In fact, scientists would prefer that the average vaccinated person never get an antibody test because it is unnecessary. In clinical trials, the US-approved vaccine elicited a strong antibody response in virtually all participants.

“Most people shouldn’t even have to worry about this,” said Akiko Iwasaki, an immunologist at Yale University.

However, the antibody test Weak immune system Or people taking certain medications — millions of people who are recipients of organ donations, have certain blood cancers, or are taking steroids or other medications that suppress the immune system. A wide range of categories including people. Increasing evidence suggests that a significant proportion of these people do not produce sufficient antibody responses after vaccination.

If you need to be tested, or just want to be tested, it is imperative that you have the right type of test. Dr. Iwasaki said as follows. People may get this false sensation that they are not developing antibodies. “

In the early days of the pandemic, many commercial trials were designed to look for antibodies to the coronavirus protein called nucleocapsid or simply N.After infection, these antibodies It was plenty In the blood.

However, these antibodies are not as powerful and do not last as long as they are needed to prevent viral infections. More importantly, antibodies to the N protein are not produced by US-approved vaccines. Instead, these vaccines elicit antibodies against another protein on the surface of the virus called spikes.

After vaccination of a person who has never been infected, testing for antibodies to the N protein instead of spikes can be rude and shocking.

credit…David rat

David ratA 46-year-old legal document writer based in Manhattan was hospitalized in Covid-19 for three weeks in March 2020, recording most of his illness and recovery on Twitter.

The following year, Mr. Rat was repeatedly tested for antibodies. For example, when you ask a pulmonologist or cardiologist for follow-up or donate plasma. His antibody levels were high in June 2020, but have steadily declined over the next few months.

The decline “did not worry about me,” Rat recalled recently. “I was told to expect them to decline naturally, but I was happy that I was still positive.”

Mr. Rat was fully vaccinated by March 22, this year. However, the April 21 antibody test ordered by his cardiologist was barely positive. Mr. Rat was stunned. “One month after being vaccinated, you would have expected to get the antibody from the roof.”

Rat Turned to Twitter For explanation. Florian Krammer, an immunologist at Mount Sinai School of Medicine in New York, asked Lat which test was used. “At that time, I saw the details of the test,” said Rat. He found that it was a test of antibodies against the N protein, not against spikes.

“By default, it just seems to give you nucleocapsid,” Rat said. “I never thought of asking for something else.”

In May, the Food and Drug Administration recommended against the use of antibody tests to assess immunity. The criticism drawn From some scientists — and provided healthcare providers with minimal information about testing. Many doctors are still unaware of the differences in antibody tests and the fact that the tests measure only one form of immunity to the virus.

Rapid tests that are generally available give yes-no results and you may miss low levels of antibodies. A particular type of lab test, called an Elisa, may provide a semi-quantitative estimate of the antibody against the spike protein.

It is also important to wait at least two weeks after the second dose of Pfizer-BioNTech or Moderna vaccine for antibody levels to rise until detectable. For some people who have been vaccinated with Johnson & Johnson, the period can be as long as four weeks.

“It’s the timing, antigens and sensitivity of the assay, which will be very important,” said Dr. Iwasaki.

November, World Health Organization Set criteria For antibody testing, it allows comparison of different tests. “Now there are a lot of good tests out there,” said Dr. Kramer. “Smallly, all these manufacturers, all these places that operate them, are adapting to the international unit.”

Dr. Dolly Segev, a transplant surgeon and researcher at Johns Hopkins University, states that antibodies are just one aspect of immunity. “It is happening under the surface that antibody tests are not directly measured.” The body also maintains a complex network of cells that respond to the network, the so-called cell-mediated immunity.

Still, for vaccinated but immunocompromised people, it can be very helpful to know that protection against the virus is not what it should be, he said. For example, transplant patients with low antibody levels may be able to use test results to convince their employers that they need to continue working remotely.

Mr. Rat is not asking for another test. Despite his test results, I was reassured enough to know that the vaccine was most likely to have brought him a new increase in antibodies. “I believe the vaccine works.”

Are you wondering if the vaccine worked?Get the right test at the right time

Source link Are you wondering if the vaccine worked?Get the right test at the right time

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