Antibodies are proteins that recognize and bind to specific viruses, bacteria, or other foreign substances and help neutralize them. COVID-19 antibodies can stay in the body for just a few months or over a year.

While experts do not know exactly how long these antibodies stay in the body, the most recent research suggests that adults who contract the SARS-CoV-2 virus develop circulating antibodies that last nearly 500 days. This is the equivalent of about 16.4 months.

A person can develop immunity from COVID-19 following vaccination, natural infection, or a combination of both. The immune system produces antibodies, also called immunoglobulins, in response to the SARS-CoV-2 virus or COVID-19 vaccines.

A person’s immune system usually provides some level of lifelong protection against the same virus after the initial infection. However, the level of protection may diminish over time. The combination of natural and vaccine-based immunity is likely to protect for a longer period.

This article looks at COVID-19 immunity after infection and how long it may last.

All data and statistics are based on publicly available data at the time of publication. Some information may be out of date. Visit our coronavirus hub for the most recent information on the COVID-19 pandemic.

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Once a virus such as SARS-CoV-2 — the virus that causes COVID-19 — enters the body, it hijacks cells to replicate itself. As the immune system fights back, specialized cells (B cells) produce proteins called antibodies. They circulate throughout the body and can recognize and bind to specific viruses and other foreign invaders.

This neutralizes the virus, preventing it from infecting other cells and helping clear it from the body. Once the immune system clears the infection, the antibodies continue to circulate around the body. This can protect against future infection from the same virus.

People who have had a previous SARS-CoV-2 infection have immune components in their blood that may provide some protection against reinfection.

However, it is still unclear how long this natural immunity lasts and whether or not it provides protection against new viral variants. More research is needed to understand the role of immunity in protecting people from COVID-19 infection.

Early in the pandemic, experts believed that antibodies and natural immunity to COVID-19 lasted for up to 3 months before diminishing. Later evidence suggested that natural immunity could last up to 11 months.

More recent research suggests that adults develop circulating antibodies that last for nearly 500 days. This equates to about 16.4 months.

Experts are unsure how long immunity to COVID-19 lasts, and it may depend on whether a person has natural or vaccine-based immunity. Natural immunity may last over a year, but more research is needed to understand vaccine-based immunity.

Early research suggested that people who had the Pfizer and Moderna COVID-19 vaccines had protection for around 4 months after a booster dose. However, some people were still becoming sick despite being fully vaccinated. And these breakthrough infections become more common.

As a result, government agencies recommend that people aged 50 years and over receive a vaccine booster or a second booster. Even with booster doses, breakthrough infections from emerging Omicron subvariants can still occur.

Researchers have noted that immune cells called T cells respond well to the Omicron variant, even 6 months following a vaccine dose. This indicates that people may have long lasting protection against the SARS-CoV-2 virus.

Hybrid immunity, which is a combination of natural and vaccine-based immunity, likely provides more protection. A 2022 study found that hybrid immunity can protect someone for more than a year.

Different variants of SARS-CoV-2 have circulated throughout the pandemic. As of November 2022, subvariant BA.5 is the predominant strain in the United States.

One 2022 study noted that previous COVID-19 infections or vaccination did not provide as much protection against the new variants as they did for the original strain of SARS-CoV-2. This means that even if a person still has COVID-19 antibodies, they may contract a strain of the virus.

Omicron can go undetected by antibodies, even if someone has had a previous COVID-19 infection or vaccination. This is called immune evasion.

A 2022 study looked at antibody levels in vaccinated people and found that subvariants including BA.5 could escape neutralizing antibodies, regardless of whether they were vaccination- or infection-induced.

However, COVID-19 vaccines elicit T cells that recognize Omicron variants. These immune cells coordinate the immune response and destroy infected cells. Therefore, COVID-19 vaccines can still protect against severe disease from Omicron, even though the virus may evade neutralizing antibodies.

Vaccines and boosters can help people maintain immunity against variants. Even with breakthrough infections, people who have received a vaccine are less likely to experience severe symptoms or require hospitalization.

They also provide added protection to people who previously had COVID-19, particularly as new variants continue to emerge.

Receiving a COVID-19 vaccine is a safer and more reliable way to build immunity than natural infection. A vaccine is controlled, consistent, and pure, while natural infection exposes people to potentially fatal complications.

People with underlying health conditions, pregnant individuals, and young children are particularly vulnerable to severe disease. As many people as possible in a population must receive a vaccine to help protect these groups.

Government agencies continue to monitor the situation and may change their recommendations on boosters and second doses in response to new evidence. However, getting a vaccine and booster shots remains the best way to protect against COVID-19.

COVID-19 immunity may last for over a year following natural infection, vaccination, or both.

However, some emerging variants can evade immune responses, so a person requires booster doses to maintain protection.

Omicron appears able to evade neutralizing antibodies, but T cells still protect against severe disease.

Therefore, vaccines remain the best way to protect against severe COVID-19, even as new variants emerge.