How Long Does COVID-19 Immunity Last?

Does COVID-19 infection confer long-term immunity? How much immunity does the COVID-19 vaccine provide? The answers to these questions are crucial as society moves forward to contain the further spread of the infection. Unfortunately, it is not yet known exactly how long COVID-19 immunity lasts, partly because the disease is so new, and partly because individuals’ immune responses differ based on factors scientists are still trying to understand. Research so far shows that COVID-19 immunity can last for years, if not decades.

COVID-19 immunity basics

When the human immune system encounters a virus such as the SARS-CoV-2 virus that causes COVID-19, it produces antibodies that target the virus and tag it for destruction by the immune system. It takes time for the body to build up enough antibodies to build a defense. Usually within a few days the bloodstream combines with the antibodies. These antibodies stay in the blood for a while and gradually decrease over weeks or months. Other immune cells, especially T and B cells , act as memory cells and are ready to help the body mount a broad immune response should it encounter the same microbe again in the future.

Researchers learned that COVID-19 antibodies are still present in most people’s blood about six months after infection. They also found that T and B cells were present up to eight months after infection. T and B cells are key to long-term immunity: T and B cells developed in response to other diseases can persist for years or decades. Data so far suggest that COVID-19 immunity has the potential to last for years.

Post-infection COVID-19 immunity

The persistence of immunity after COVID-19 may depend on the severity of the disease and the overall health of the individual’s immune system.

Read More  Anti-wrinkle cream: The 4 best products + 3 tips against wrinkles

A study of 77 people, mostly recovering from mild cases of COVID-19, found that within four months of infection, antibody levels dropped significantly, but the rate of decline slowed thereafter. 11 months after infection, researchers were still able to detect COVID-19 antibodies. (However, no one knows yet what level of antibody presence is required to build an effective defense against infection.)

According to an article published in the May 2021 issue of the journal Nature, some researchers believe that many people who contract COVID-19 will produce antibodies for decades.

Scientists are still studying the persistence of B and T cells produced in response to COVID-19. However, they do know that some people infected with SARS-CoV-1 , the coronavirus that was the culprit of the 2002-2004 SARS epidemic, still have the corresponding B and T cells. For example, some survivors of the 1918 flu epidemic still had some immunity to that particular flu virus nearly 90 years later.

COVID-19 immunity after infection is not absolute. The first case of COVID reinfection was reported on 28 August 2020. A summary from the World Health Organization published in May 2021 said, “ Current scientific data suggest that immune responses in most people remain vigorous and protective against reinfection for at least 6 years. 

Post-vaccine COVID-19 immunity

COVID-19 vaccines first received emergency approval in the United States in December 2020, so researchers don’t yet have a lot of data on post-vaccination immunity. However, preliminary studies suggest that COVID-19 vaccine immunity may last for years, based on participants’ proven strong immune activity 15 weeks after the first dose of vaccine.

Read More  Which Doctor to Go to for Groin Pain?

It is currently unclear whether booster vaccines will be required to maintain immunity to COVID-19 after vaccination. Researchers continue to study the duration of COVID-19 immunity after vaccination and infection.

Related Posts

Leave a Reply

Your email address will not be published.