If you are one of the millions of Americans who already have Covid-19, you may be wondering how long you have been immune from the coronavirus. In the early days of the pandemic, most people thought that getting infected had at least one benefit. It means that you will be protected from future encounters with the virus. However, reinfection seems to be common, as the latest waves are heading to the western part of the country and show no signs of virus mitigation. Already, many have reported a second or third infection with a new variant.
Experts warn that exposure to coronavirus by vaccination or infection does not mean complete protection from future infections. Rather, the coronavirus has evolved to behave like a closely related cousin that causes the common cold and is repeatedly transmitted throughout life.
“Since this pandemic began, I thought that Covid-19 would eventually become an inevitable infection, and everyone would be infected many times. That’s why the new respiratory virus is a human population. Because it’s a way to settle in. ” Ameshua Dalha, an infectious disease specialist at Johns Hopkins University.
However, the coronavirus, like other common cold viruses, has not yet adapted to a clear seasonal pattern. It can also cause debilitating symptoms that last for months or years, killing millions of people. So what can we do to protect ourselves from not only infection but also reinfection? We asked experts to answer frequently asked questions.
How long will your immunity last after you get Covid?
Prior to Omicron, reinfection was rare. A team of scientists led by Laith Abu-Raddad of Weill Cornell Medicine-Qatar estimated that the match against Delta or previous coronavirus strains was approximate. 90% effective in preventing reinfection For both vaccinated and unvaccinated people. “But Omicron really changed that calculation,” said infectious disease epidemiologist Dr. Abu Raddad.
After the advent of Omicron, previous infections provided only about 50 percent protection against reinfection, a study by Dr. Abu Raddad showed. The coronavirus had so many mutations in the peplomer that the new version was more contagious and was able to evade immunity. This means that you can catch the Omicron version after recovering from the old non-Omicron variants. After overcoming another version, you may even get sick with one of the new Omicron subvariants.
Other factors also increase your vulnerability to reinfection, starting with how long you have had Covid. Immune defense tends to decline after infection. A study published in October 2021 estimates that reinfection can occur soon. 3 months after being infected with Covid-19.. These findings are based on the coronavirus genome and explain the expected reduction in antibodies that may repel the virus, but in this study, like Omicron, which is radically different from older variants. No new variants were considered. Due to the difference in Omicron, your protection may decline even faster.and Study published in February Although not yet peer-reviewed, Danish scientists have discovered that some people have re-infected the BA.2 substrain of Omicron 20 days after being infected with the original Omicron BA.1.
As the virus now infects more people, it is more likely to be exposed and re-infected, Dr. Abu Raddad said. And while it’s unclear if some people are simply vulnerable to Covid-19 reinfection, researchers are beginning to find some clues. Elderly people and people with immunodeficiency have very low or very low antibody quality, which can make them more susceptible to reinfection, Dr. Abu Raddad said.And early studies show that a small number of people have a genetic defect that makes them crippled. An important immune molecule called type I interferon, Increases the risk of serious Covid symptoms. Further studies have shown that such differences also play a role in reinfection.
For now, potential cases of Covid require treatment for new symptoms such as fever, sore throat, runny nose, and changes in taste and smell, and to be tested to see if they are positive again.
Is the subsequent infection more or less serious?
Fortunately, if the virus bypasses the initial antibody defense, the body can require immune cells, such as T cells and B cells, to suppress the reinfection. T cells and B cells can take several days to be activated and begin to function, but they tend to remember how to fight the virus based on previous encounters.
Shane Crotty, a virologist at the Lahora Immunology Institute in California, said:
Many of these immune cells repeatedly build their protection, Dr. Crotti said. This means that those who have been vaccinated and boosted are well equipped to make it public with the coronavirus. Similarly, previously infected people can prevent high levels of virus replication in the event of reinfection. And most people who have recorded encounters with both vaccines and coronaviruses build hybrid immunity that may provide the best protection.
As a result, the second or third infection may be shorter and less severe.
Dr. Abu Raddad, who is tracking reinfection among a large number of people in Qatar, has already begun to see this. Promising pattern of patient records: From the start of the pandemic to May 2021, none of the more than 1,300 reinfections identified by his team led to hospitalization in the ICU and none were fatal.
But just because reinfection isn’t so serious doesn’t mean it’s terrible. You may still have a fever and experience body aches, brain fog and other symptoms. And there’s no way to know if your symptoms will last longer, Covid, said Dr. Adalja.
Some researchers assume that the risk is highest immediately after the initial infection, but each Covid infection can force you into a Russian roulette game. One of the risk factors for Longcovid is the presence of high levels of virus in the system early in the infection, and the viral load is likely to be very high the first time it is infected, Dr. Abradad said. .. In subsequent infections, he said, your body is ready to fight the coronavirus, so you may be able to keep the virus at low levels until it is completely eliminated.
What can you do to reduce the risk of reinfection?
Many of the tools and actions that help protect against infection can help avoid reinfection, Dr. Abu Raddad said. “There is no magical solution to Covid’s reinfection.”
For example, it is a good idea to get vaccinated and boosted even after vaccination with Covid. You can be shot just by waiting a few weeks after infection. Vaccines will increase antibody levels, and studies show that they are effective in preventing serious consequences if you get sick again. “Scientific confidence in vaccine-induced immunity was much higher than infection-induced immunity,” Dr. Crotti said.
Additional measures such as masking indoors and in crowded spaces, increasing social distance, and improving ventilation where possible can provide another layer of protection. However, most people and communities have largely abolished these protections, so it is up to individuals to decide when to adopt additional precautions based on the risk of being infected with Covid and how much they want to avoid it. Is the responsibility of.
“If you got infected last week, you probably don’t need to mask,” Dr. Adalja said. “But about a month after the infection, when new variants begin to spread in the United States, it may make sense for high-risk individuals to do it, either to go on a cruise right away or. Anyone trying to avoid Covid infection because of a negative PCR test for other reasons should consider taking precautions. Covid’s protection does not have to be universal. “
