How long does your vaccination against the coronavirus last? – Don’t eat this that

If you are fully vaccinated, you may be excited to get back together with family and friends. You may even be planning a winter vacation. But there are still nagging questions about how long the protection against the coronavirus vaccines will last. For example, will your shot decrease gradually or suddenly? Do you need one booster? “We can only say that a vaccine is protective as long as we measure it,” says Jaimie Meyer, an infectious disease specialist at Yale Medicine, MD, MS. Read on to find out more – and to ensure your health and that of others, don’t miss this one Sure Signs You’ve Already Had COVID

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Vaccine longevity became a hot topic in August, when some studies began to suggest vaccine efficacy was declining, although data also showed the vaccines were still highly effective against hospitalization. In one study reported by the Centers for Disease Control and Prevention (CDC)New York state data showed that the effectiveness of vaccines against infection fell from 91.8 to 75%.

Data on vaccine withdrawals contributed to a fall 2021 decision to make booster shots available – the CDC says all adults 18 years of age or older should receive a booster six months after completing their primary vaccination course if they started with Pfizer-BioNTech or Moderna. or two months after receiving the J&J single vaccine. Teens ages 16 or 17 can also get the Pfizer-BioNTech booster, which the FDA approved in December 2021 for that age group. A mix-and-match policy allows people to use one of three COVID-19 vaccines available in the US as a booster injection, regardless of which vaccine someone had before their primary vaccination.

Portrait of doctor wearing face mask and clipboard looking at camera in hospital.
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Pfizer and Moderna monitored immunity in people who received their vaccines in the first clinical trials – both companies had reported strong overall efficacy after six months. (Pfizer reported on its efficacy in a pre-print that has not been assessed by outside scientists; Moderna released a company statement.)

One thing researchers check in vaccine recipients is the levels of antibodies, which are proteins produced by the body’s immune system when it detects harmful substances, which can be easily measured from blood samples. “Antibodies are a really good marker for protection against infection, so we’ll be monitoring those levels for as long as we can measure them,” says Akiko Iwasaki, PhD, a professor of immunobiology at Yale School of Medicine.

A report in The New England Journal of MedicineNEJM) in April showed that 33 participants who received the Moderna vaccine during the phase I trial had a gradual decline in antibody protection — and based on the slope, Iwasaki says that’s hopeful news. “If antibodies decline very quickly, you would expect that to last for only a short time.” The slow decline raises hopes that the mRNA vaccines will be protective for at least a year, if not longer, she says. (It should be noted that the trial took place before Delta became the predominant virus variant in the US last summer; as of mid-December 2021, Omicron is the predominant virus in the US)

Doctor with syringe, medical injection in hand with glove.
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Another measure is T cells, which scientists are still studying for their ability to kill virus-infected cells in the context of COVID-19, and may also provide important protection. T cells are harder to measure, Iwasaki says. But they can be important – last year, a study in Nature showed that people infected with Severe Acute Respiratory Syndrome (SARS), another coronavirus outbreak that killed nearly 800 people in 2003, maintained T-cell immunity 17 years after they recovered.

Yet another way to predict how long protection may last is to look at natural immunity, says Dr. Meyer. This means studying immunity that people have developed after infection with COVID-19. “We know for at least the first few months after symptomatic illness — and even longer — that people are unlikely to become reinfected,” she says.

But it’s important to know that the immunity induced by the mRNA vaccines is stronger and more reliable than the natural immunity, Iwasaki says. That’s because levels of natural immunity often vary from person to person. “Vaccines normalize the response to a very high level, where it uniformly turns everyone on,” she says. “If you start at the high level, even if you start to decrease from that level, it will take you much longer to need a booster.”

This is one reason why the CDC recommends vaccinations for both people who have had a COVID-19 infection and those who have not.

Moderna and Pfizer Covid-19 Vaccine
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No one knows for sure if one vaccine lasts longer than another. Instead, one question might be whether Pfizer and Moderna’s mRNA vaccines, which had a particularly potent response, also have the potential to last the longest, says Dr. Meyer.

The two mRNA vaccines use a relatively new technology that delivers a small piece of genetic code of the SARS CoV-2 virus into the body to provide instructions for making copies of spike proteins that will stimulate an immune response. The Johnson & Johnson vaccine takes a more traditional approach that uses an inactive adenovirus (a common virus that can cause colds and other illnesses when active).

“The mRNA vaccines are a new tool that has not been widely rolled out with any other virus, and so far they have had a much more robust immune response in clinical trials,” said Dr. Meyer. Whatever the answer to the question of which one will last the longest, Pfizer and Moderna’s mRNA vaccines work the same way, so it seems likely they’ll have a similar impact on immunity, she says.

While both vaccines are still considered highly effective, some recent studies have shown that Moderna is more protective. A study published in The New England Journal of Medicine found that the Moderna vaccine was 96.3% effective in preventing symptomatic disease in health professionals, compared to 88.8% for Pfizer. Another study, from the CDC, found that Moderna’s effectiveness against hospitalization remained stable over a four-month period, while Pfizer’s decreased from 91% to 77%. But scientists say more data is needed to fully understand the differences between the two vaccines.

“It’s also possible that the duration of immunity is somewhat dependent on the patient,” adds Dr. Meyer to it. While more research is needed, there may be differences in the immune response from person to person based on factors such as age, medical conditions, and medications they may be taking. Overall, however, the mRNA vaccines appear to be so effective that they level the playing field in achieving protection against infection, says Dr. Meyer.

Brunette woman wearing a KN95 FPP2 mask.
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It’s critical that as many people as possible get their primary vaccination shots, says Dr. Meyer. In December 2021, the CDC approved a recommendation to choose the Pfizer-BioNTech or Moderna vaccines, in response to concerns about rare blood clots associated with Johnson & Johnson’s injection.

“The good news is that Pfizer and Moderna have made it easy to update their mRNA vaccines,” said Dr. Meyer. “It just needs some tweaking, like computer code that needs a few minor tweaks. It’s relatively easy to build.” It’s also important to follow the CDC’s recommendations about booster shots.

“The hope is that the number of cases will decrease and that more people will be less likely to be exposed.” That advice is especially important with the Delta and Omicron variants, which have been shown to be more contagious than previous variants, prompting the CDC to issue stricter guidelines urging everyone — vaccinated or not — to wear masks indoors in high-risk areas. high transmission.

Even if Delta and Omicron go away, “I think those preventative measures will become even more important as the year goes by because your immunity may wane over time,” says Dr. Meyer.

Meanwhile, people need to think about the amount of virus activity in their area and what they need to do to protect the immunocompromised people, and children and others who can’t get the vaccine. “I say to my family, ‘It’s great that you’ve been vaccinated. That’s great, and you’ll have a lot more freedom and flexibility. But even the vaccines don’t have a 100% guarantee, so whatever you do, you want to keep the weighing risks.'” she says. And to protect your life and the lives of others, do not visit any of these 35 places you are most likely to get COVID

This article was published in Yale Medicine.

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