The current logic from DC is that we must make COVID vaccines an annual affair. My thoughts originally was that this may be a good idea. The along comes immune imprinting. In Nature they note:
Imprinting equips the immune system with a memory of an invader that helps it prepare to do battle again. The key players are memory B cells, which are generated in lymph nodes during the body’s first exposure to a virus. These cells then keep watch in the bloodstream for the same foe, ready to develop into plasma cells that then churn out antibodies. The snag comes when the immune system encounters a similar, but not identical, strain of a virus. In this case, rather than generate new, or ‘naive’, B cells to produce tailored antibodies, the memory-B-cell response kicks in. This often leads to the production of antibodies that bind to features found in both the old and new strains, known as cross-reactive antibodies. They might offer some protection but are not a perfect fit to the new strain. Imprinting was first observed in 1947 by Jonas Salk and Thomas Francis, the developers of the first flu vaccine, together with another scientist, Joseph Quilligan1. They found that people who had previously had flu, and were then vaccinated against the current circulating strain, produced antibodies against the first strain they had encountered. Francis gave the phenomenon the tongue-in-cheek name ‘original antigenic sin’, although today most researchers prefer to call it imprinting.
Namely there seems to be a law of diminishing returns. So how to get around this? They continue:
So what does this mean for our current vaccines? Boyton says that they are “brilliant” in their ability to protect against serious illness. But, she says, now that most people are protected, scientists should focus on finding vaccines that can overcome imprinting, to halt the spread of the virus, not just the severity of disease. “Now we’re in a slightly different place, we’ve got to think slightly differently.” Seder agrees that vaccines will need to change if they are to limit infection and transmission, rather than just prevent atalities. He says that one approach would be to use live vaccines, which would persist in the body for 5–10 days and might produce a more effective response. But live vaccines pose greater risks, particularly for vulnerable people, owing to the dangers of even a weakened virus multiplying.
Live vaccines do offer an option, namely they give the immune system multiple antigen targets to go after. Each new variant may have multiple new antigen targets and this may enhance the response. The problem with live vaccines however is production, lots of eggs. Yet we do this with flu vaccines now.
Will our brilliant Government clones ever address this option? Doubtful. It is really nothing new but it seems politics prevent the poisoning of the public.
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