How long does immunity to covid-19 last? Will a second infection get worse? How can I avoid this? – Health

If you are one of the millions of people who have already been hired Covid-19, you should ask how long you will be immune to the new coronavirus. At the beginning of the pandemic, most people believed that being infected had at least one advantage: being protected from future pollution. But as the final wave makes its way to the west of the country (United States of America) and the virus shows no signs of cooling again it seems that infections are more common. Many people are already reporting new or tertiary infections with new variants.

Experts warn that exposure to coronavirus – through vaccines or infections – does not mean that people are completely protected from future contamination. Instead, coronaviruses are evolving like other viruses that cause colds and repeatedly infect the population over a lifetime.

“Almost from the beginning of the pandemic, I thought that Covid-19 would become an unavoidable infection, that everyone would have it eleven times, thus establishing a new respiratory virus in the human population,” said Amesh Adalja. specialist in diseases.infectious Johns Hopkins University.

However, coronavirus does not yet fit into well-defined seasonal patterns like other common cold viruses. The disease can still cause symptoms that can last for months or years in some people, and has claimed the lives of thousands of others. So what can you do to protect yourself not only from infections but also from viruses? We asked these questions to different experts.

How long will my immunity last after taking covid-19?

Prior to the Omicron variant, re-infections were rare. A team of scientists led by infectious disease researcher Laith Abu-Raddad of Qatar’s Weill Cornell School of Medicine in Qatar estimated that a previous strain of Delta variant contamination or coronavirus was 90% effective in preventing re-infection. people without vaccines. “But [variante] omicron it really changed that calculation, “Abu-Raddad said.

Since the creation of Ômicron, previous infections have again provided only 50% protection against infection, the Abu-Raddad study revealed. Coronavirus has accumulated so many mutations in its Spike protein that new versions have become more transmissible and have been able to bypass the immune system. This means that people can sign up for the Omicron version after recovering from an old non-Omicron virus. It’s possible to get sick of hiring a younger sub-variant of Omicron after getting another version.

Other factors may also increase the vulnerability to re-infection. One of them is the time since the covid-19 virus spread. After an infection, the defenses of the immune system weaken. A study published in October 2021 estimated that someone could have a re-infection within three months of becoming infected with the new coronavirus. Although these findings are based on the genome of a coronavirus, and were responsible for the expected decline in antibodies that could fight the virus, the study did not take into account new variants such as Omicron, which were completely different from older variants. Due to the difference in Omicron, its protection can be reduced even earlier.

In a study published in February 2021, which has not yet been reviewed by peers, Danish scientists found that some people were re-infected with BA.2, the Omicron sub-line, after being infected with the original Omicron variant 20 days later.

Now that the virus is infecting more people, the chances of suffering and re-infection are even higher, says Abu-Raddad.

And while it’s unclear whether some people are vulnerable to Covid-19 re-infection, researchers are beginning to find some clues. Elderly or immunocompromised people can produce a lower or weaker amount of antibodies, which can lead to re-infection, says Abu-Raddad. And early research also found that some people had a genetic defect that could damage a crucial immune molecule called type I interferon, putting them at greater risk for severe Covid-19 symptoms. Other research has shown whether these differences have a role to play in re-infection.

But for now, you should treat all new symptoms, including fever, sore throat, runny nose, or changes in taste and smell, as a potential case of Covid-19, and have a test to confirm that you are actually sick. re-infected.

Will infections be more or less aggressive later on?

The good news is that the body can rely on immune cells, such as T cells and B cells, if the virus to thwart a re-infection exceeds the defenses of the initial antibodies. B and T cells may take a few days to activate and start working, but they tend to remember how to deal with the virus based on previous infections.

“Our immune systems have all sorts of weapons if they go through the door to try to stop the virus,” says Shane Crotty, a virology specialist at La Jolla Immunology Institute in California.

Many of these defense cells are building their defenses over and over again, Crotty explained. This means that people who are vaccinated and immunized with booster shots are well equipped to fight coronavirus. Also, people who have been infected before are able to prevent the virus from recurring if they become infected again.

As a result, the second or third re-infection is usually shorter and less aggressive.

Abu-Raddad, who monitors the re-infections of large groups of people in Qatar, has already begun to see this pattern in patient records: none of the 1,300 re-infections identified by his team from the start of the pandemic to May 2021. they were strong enough to send someone in need of intensive care from the hospital, and none of them were fatal.

But having more serious infections doesn’t mean it’s easy to deal with. There may also be fever, body aches, headaches and other symptoms. And it is unknown at this time what he will do after leaving the post.

Each Covid-19 infection may put people in a sort of Russian roulette wheel, although some researchers believe that the risk is higher immediately after the first infection. One of the long-term factors of Covid-19 is the high level of the virus at the beginning of an infection, which makes it likely to have a high viral load the first time you become infected, says Abu-Raddad. In later infections, the body will be better prepared to fight the coronavirus and will be able to keep the virus low until it is completely eliminated from the body, the researcher added.

What can be done to reduce the risk of infection?

Many tools and behaviors that protect against infections can still help prevent infection again, says Abu-Raddad. “There is no magic solution to coronavirus re-infection.”

Getting vaccinated and receiving a booster dose, for example, is a good idea even after taking covid-19. But you will have to wait a few weeks after getting an infection to receive the immunizer. Vaccines will increase your antibody levels, and research shows that they are effective in preventing serious illness if someone gets the disease again. “Scientific confidence in vaccine-induced immunity has been and is far greater than infection-induced immunity,” says Crotty.

Additional measures such as the use of masks indoors and in crowded places, maintaining social distance and improving the air ventilation in the surroundings can provide another layer of protection when possible. But since most individuals and groups have abandoned these protective measures, it is up to each individual to decide when to take additional measures against Covid-19, depending on the risk of contracting the disease, and how much they want to avoid.

“If you had an infection last week, you probably shouldn’t wear a mask,” Adalja said. “But after a month or so of infection, and new variants are circulating in the U.S., it makes sense for high-risk people to start doing this. [usar máscara]. People who are trying to avoid Covid-19 will want to consider taking precautions because they will soon have a cruise or need a negative PCR test for some other reason. Disease shields do not have to be one-size-fits-all. ”

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