Immunity
Immunity
Subject: Science
Section: Disease
Context: ‘Omicron infection narrowing the gap between unvaccinated and vaccinated individuals Immunity’
Content: The SARS-CoV-2 virus continues to adapt to the human host, it has been transmuting itself which can escape the immune protection
Immunity to a disease is achieved through the presence of antibodies to that disease in a person’s system. Antibodies are proteins produced by the body to neutralize or destroy toxins or disease-carrying organisms. Antibodies are disease-specific.
For example, a measles antibody will protect a person who is exposed to measles disease but will have no effect if he or she is exposed to mumps.
There are two types of immunity: Active and Passive.
- Active Immunity: When exposure to a disease organism triggers the immune system to produce antibodies to that disease. Active immunity can be acquired through natural immunity or vaccine-induced immunity.
- Natural immunity is acquired from exposure to the disease organism through infection with the actual disease. A mild case of an illness may not result in strong natural immunity.
What is vaccine-induced immunity for COVID-19?
Vaccine-induced immunity is being fully vaccinated with an approved or authorized COVID-19 vaccine. The protection from the vaccines may wane over time so additional doses (boosters) are now authorized for certain populations. These boosters can extend the powerful protection offered by the COVID-19 vaccines.
If natural immunity is present, do you still need a COVID vaccine?
Yes, the COVID-19 vaccines are recommended, even if one had COVID-19. The recent research studies support getting vaccinated even if you have already had COVID-19: Vaccines add protection.
- The U.S. Centers for Disease Control and Prevention (CDC) released a report on Oct. 29, 2021, that says getting vaccinated for the coronavirus when you’ve already had COVID-19 significantly enhances your immune protection and further reduces your risk of reinfection.
- A study published in August 2021 indicates that if you had COVID-19 before and are not vaccinated, your risk of getting re-infected is more than two times higher than for those who got vaccinated after having COVID-19.
- Another study published on Nov. 5, 2021, by the U.S. Centers for Disease Control and Prevention (CDC) looked at adults hospitalized for COVID-like sickness between January and September 2021. This study found that the chances of these adults testing positive for COVID-19 were 5.49 times higher in unvaccinated people who had COVID-19 in the past than they were for those who had been vaccinated for COVID and had not had an infection before.
- A study from the CDC in September 2021 showed that roughly one-third of those with COVID-19 cases in the study had no apparent natural immunity.
Vaccine-induced immunity is acquired through the introduction of a killed or weakened form of the disease organism through vaccination.
If an immune person comes into contact with that disease in the future, their immune system will recognize it and immediately produce the antibodies needed to fight it. Active immunity is long-lasting, and sometimes life-long.
Passive Immunity is provided when a person is given antibodies to a disease rather than producing them through his or her own immune system.
- Pregnant woman wearing protective face mask in blooming park
- A newborn baby acquires passive immunity from its mother through the placenta.
- People can also get passive immunity through antibody-containing blood products such as immune globulin, which may be given when immediate protection from a specific disease is needed.
The major advantage to passive immunity is that protection is immediate, whereas active immunity takes time (usually several weeks) to develop. However, passive immunity lasts only for a few weeks or months. Only active immunity is long-lasting.
