The Doctrine of Original Antigenic Sin
COVID-19 vaccines and young healthy children
by Pinedale Online!
December 11, 2021
It’s a crazy name, but an interesting concept worth throwing into the thought mix for parents trying to decide whether to have their healthy young children get the COVID-19 vaccine.
"The term "original antigenic sin" (OAS) was first used in the 1960s to describe how one’s first exposure to influenza virus shapes the outcome of subsequent exposures to antigenically related strains. In the decades that have passed, OAS-like responses have been shown to play an integral role in both protection from and susceptibility to infections." (1)
The reason this is worth considering is because healthy young children have minimal risk in getting COVID-19. They seem to experience mild symptoms from getting the virus and recover fairly quickly. They then gain a degree of natural immunity to future exposures to variants of the virus. That immunity can last more than a year, based on current observations. The vaccine effectiveness in adults wanes greatly between three to six months, and does not prevent getting the virus or transmitting it to others. To date in Wyoming, there have been no deaths associated with COVID-19 in the two years of the pandemic for anyone age 18 or under. There have been nearly 15,000 lab-confirmed cases in that age group. The question then becomes are there health risks associated with getting the vaccine, and if so, what are those in comparison to health risks of getting the virus?
The Centers for Disease Control (CDC) asserts that health risks from the COVID-19 vaccines are rare. They do acknowledge that the vaccines do not sterilize the virus and even people who are vaccinated can still get and transmit the disease. They also acknowledge rare reports of increased risk of heart problems (myocarditis) from the vaccine. They also acknowledge possible rare allergic reactions and blood clots (thrombosis) from the vaccine. It is too early to tell possible long-term health effects from the virus or the vaccines. The CDC continues to say the vaccines are safe and effective for youth and adults.
That being said, the concern for discussion is that by vaccinating millions of healthy, low-risk young children with a man-made vaccine that is targeting a now-mostly-over strain of the COVID-19 virus (Alpha - most people now are getting Delta, which the vaccines were not formulated for), it will train the immune system of these children to trigger on a narrow-focused version of the virus and not work as well to fight newer variant versions. This may reduce the adaptive ability of the child’s body to adequately protect them as they have new exposures over the course of their lifetime. In other words, the COVID-19 vaccine may actually reduce the ability of the child’s immune system to create optimum antibodies against subsequent versions of the virus at later times in the person’s life.
At this point, this is still all very preliminary. It is too early for all the ramifications to be known of vaccinating healthy young children with vaccines that do not sterilize the virus. There is increasing evidence that the first exposure of a child to an influenza virus is extremely important because it sets the stage of the ability of their body to create robust antibodies to protect them from future exposures to variants and the degree of their illness in response. While this is still an early discussion, it is important for parents to be aware of, and follow, the medical research in this area as they make health decisions for their children.
Below are excerpts from related articles on this subject. Click on the links below for additional reading related to each excerpt.
"Original antigenic sin, also known as antigenic imprinting or the Hoskins effect, refers to the propensity of the body's immune system to preferentially utilize immunological memory based on a previous infection when a second slightly different version of that foreign pathogen (e.g. a virus or bacterium) is encountered. This leaves the immune system "trapped" by the first response it has made to each antigen, and unable to mount potentially more effective responses during subsequent infections. Antibodies or T-cells induced during infections with the first variant of the pathogen are subject to a form of original antigenic sin, termed repertoire freeze." (2)
"…approximately 40 years ago, it was observed that sequential influenza vaccination might lead to reduced vaccine effectiveness (VE). This conclusion was largely dismissed after an experimental study involving sequential administration of then-standard influenza vaccines. Recent observations have provided convincing evidence that reduced VE after sequential influenza vaccination is a real phenomenon. We propose that such reduction in VE be termed "negative antigenic interaction," given that there is no age cohort effect. In contrast, the potentially positive protective effect of early influenza virus infection later in life continues to be observed. It is essential that we understand better the immunologic factors underlying both original antigenic sin and negative antigenic interaction, to support development of improved influenza vaccines and vaccination strategies." (3)
"The first influenza virus infection during childhood, termed immune imprinting, is recognised for its influence on subsequent infections and vaccinations. The imprinting event initiates a cascade of innate and adaptive immune responses leading to an immunological memory retained over a person’s lifetime." (4)
"A phenomenon called "original antigenic sin" (OAS) was firstly proposed by Francis in 1960. This phenomenon occurs in the second exposure of the immune system to a similar pathogen to which it has previously been exposed. In this situation, the immune system progresses to the memory response, generating cross-reactive antibodies that may not be effective against the new pathogen. In addition, it has been speculated that overproduction of memory B cells could compromise the activation of naïve B cells capable of producing efficient and novel antibodies. In this way, OAS can trigger immune evasion of the emerging variants in those who had been affected by or vaccinated against former versions of the pathogen." (5)
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