How the COVID 19 Vaccine Reduces Immune Response Before Vaccination
How the COVID 19 Vaccine Reduces Immune Response Before Vaccination.Getting vaccinated against COVID 19 protects you and people around you who may be more vulnerable to severe illness. It can also help limit the spread of the virus.
The strength of immunity you build depends on a variety of factors, including the type of infection you have and how long it lasts. WHO is investigating these and other factors to better understand how protection against COVID 19 can be built.
Vaccine immunity
Vaccines contain antigens that trigger your body’s immune system to make antibodies to fight disease in the future. Those antibodies can last for years, or even decades. They also stimulate your body to produce memory B cells, which remember the pathogen and attack it when you’re exposed again.
Booster doses of vaccine can be given in childhood to ensure that immunity lasts through adult life. This is essential for achieving herd immunity, a situation in which a large group of people becomes immune to the same disease.
Immunity is a complex process that involves both short-lived antibodies and long-lived CD8+ memory T cells, as well as a range of other immune cell types, including killer T cells and B cells. Some vaccines require several doses to generate a long-lasting antibody response, while others induce very high levels of immunity in a single dose.
Many vaccines are made from weakened or killed versions of a disease-causing germ, so they can’t infect you when you get them. That’s why they’re safe to give to infants or people with weak or failing immune systems, like cancer patients.
The mRNA COVID 19 vaccines are better at revving up killer T cells to fight future infection by SARS-CoV-2, the virus that causes COVID-19, than natural infection by SARS-CoV-2, Stanford Medicine investigators have found.
But they’ve also found that prior SARS-CoV-2 infection reduces your killer T cell response to vaccination. And they’ve also found that the antibodies in convalescent plasma (the liquid part of your blood) from people who’ve had COVID-19 don’t help improve your survival or lessen your need for a ventilator.
These findings raise questions about whether it’s safe to vaccinate people who have had COVID-19 and want to get a vaccine for it, or who don’t have enough immunity from other vaccines to protect them.
It’s important to understand the differences between natural immunity and vaccine-induced protection so you can decide if it’s right for you. The most important factor is whether you’re healthy and can withstand the side effects of a vaccine. That’s why it’s best to choose a vaccine with the most proven protection.
Natural immunity
When you get sick, your immune system responds to the germs that caused it by creating a variety of cells, such as white blood cells and T-cells. These cells recognize the virus in your body, identify it and destroy infected cells. They also help prevent future infections by sending special proteins called antibodies to your bloodstream.
However, some people may not develop natural immunity if they don’t get vaccinated. This is because their immune systems are weakened or damaged by diseases like cancer or other medical conditions.
Immunity from natural infection is short lived, and it usually disappears within about 90 days. This is because the antibody levels that were triggered by natural infection decline as time passes, making you more susceptible to getting COVID 19 again.
The good news is that natural immunity can be boosted by vaccination, and the vaccines for COVID 19 can create much stronger and longer lasting protection than natural infection. So even if you’ve had the disease before, getting a COVID 19 vaccination can protect you from severe illness and death.
Vaccines can also be used to help achieve herd immunity, a term that means a community is protected from contagious diseases when most people are vaccinated against it. This helps prevent outbreaks of disease, which can be devastating for the health care system and the community.
Herd immunity is a key goal of immunization, especially in vulnerable groups. Often, herd immunity occurs when enough people have been vaccinated against a particular disease to develop protective antibodies against it. This helps keep people who can’t be vaccinated, such as newborns, safe from the disease and reduces the overall number of people with the disease.
But herd immunity is not easy to achieve, especially when a group of people has an unequal amount of access to the vaccines. This can happen if communities in one country have high vaccination rates and surrounding areas don’t.
Another reason herd immunity is difficult to achieve is that many countries have different distributions of the COVID 19 vaccine. If a certain country or region has high vaccination rates and other countries don’t, the COVID 19 virus can spread easily between people in those communities.
Hybrid immunity
Hybrid immunity is the immune system’s ability to generate antibodies and other protective factors against multiple variants of a disease. It’s more effective and durable than vaccine-induced immunity alone, which depends on many factors, including the timing of vaccination and a person’s sensitivity to a particular virus.
In a recent study, researchers used blood samples from people who were previously infected with COVID 19 and those who received the COVID 19 vaccine to compare how they responded to three different live variants of the virus. They found that those with hybrid immunity generated a stronger immune response against the Omicron variant of COVID 19 than those who had a prior infection but didn’t receive a vaccine.
This is a good thing, because it means they’re more likely to survive and not get sick again. However, it also means they need to be vaccinated with another dose of the COVID 19 vaccine.
But, before that happens, their immunity is likely to be weakened. That’s the result of things like viral evolution and changes in how a disease interacts with the immune system, according to OHSU.
When the Omicron COVID 19 variant evades the immune system, it causes increased transmission and breakthrough infections. These are the kind of infections that can make COVID 19 so dangerous and can put communities at risk for long-term consequences, such as death or disability.
To better understand the role of immune system amplification in boosting resilience, the researchers looked at a group of 104 OHSU employees who had been vaccinated with a COVID 19 vaccine but were also infected with the virus. The researchers divided them into two groups: ones that had hybrid immunity, which boosted their killer T cells, and those that didn’t.
The vaccinated participants in the hybrid immunity group were much more likely to have a high-functioning antibody response against the Omicron COVID 19 variant than were those in the vaccine-only group, and they had better protection against hospitalisation or severe illness at 12 months. But, as Dr Niklas Bobrovitz, one of the study’s authors told ABC News, the study also shows that “it’s really important to be vaccinated because you can’t always predict how strong your immunity is and what kind of immune response you have when you have the disease.”
Vaccine response
The immune system is a complex system that reacts to different threats in a variety of ways. Its main function is to fight off viruses and other pathogens that could harm our bodies. This response includes a mix of both natural immunity and vaccines.
Vaccines use the body’s own cells to trigger an immune response. They do this by exposing the person to weakened or inactive parts of an antigen (a protein that causes disease) so that their own immune cells can respond appropriately.
Immunity from vaccination also depends on the type of vaccine and how well it stimulates the immune system to produce antibodies against the virus. Some vaccines induce antibody responses that last for years, while others cause less-permanent protection.
Some people who get a COVID 19 vaccine develop high levels of protective antibodies against the disease, while others may not. This is especially true for people who are older or have a condition that makes them more vulnerable to the infection, such as cancer or immunosuppression medications.
Researchers found that the COVID 19 vaccine may reduce the number of immune cells called CD4+ T cells and CD8+ T cells in the blood. Those cells are important for fighting off the virus and killing any other infected cell that comes into contact with them.
This is what’s known as a reduction in immunity response before vaccination, and it’s referred to as “original antigenic sin.” It has been linked to other diseases as well, such as dengue52.
Similarly, researchers have shown that SARS-CoV-2 infection can reduce the number of killer T cells in the blood. In a study, SARS-CoV-2-specific killer T cells in the blood of people who had Covid were less than one-seventh as prevalent three weeks after they received two doses of the Pfizer-BioNTech COVID 19 mRNA vaccine than they were in blood samples from never-infected patients receiving two doses of the same vaccine.
Despite the evidence for reduced immunity after vaccination, it’s still important to keep getting the vaccine and to boost your protection by regularly getting additional primary shots and boosters. This will help protect you from this virus in the future, regardless of your health status or whether you’ve been vaccinated previously.
