The protection of less effective vaccines against COVID-19 may fade more quickly. The Sinopharm vaccine may already be showing some signs of this decline. Clinical trials indicate that it is 78 percent effective, but United Arab Emirates and Bahrain They are already offering boosters to people who received the Sinopharm vaccine to bolster their diminishing immunity.
How will we know that vaccines are losing their effectiveness?
Researchers are looking for biological markers that can reveal when a vaccine’s protection is no longer sufficient to contain the coronavirus. It is possible that a certain antibody level marks the threshold: if your blood has levels above that threshold, you are in good condition, but if it is below, you run a greater risk of contagion.
Some preliminary studies suggest that these markers, known as correlates of protection, are present in the case of vaccines against COVID-19. Research is underway to find them.
“That will teach us a lot,” said H. Clifford Lane, deputy director of clinical research and special projects at the US National Institute of Allergy and Infectious Diseases.
What about the variants?
We may very well need reinforcements to block the variants, but that is not yet clear.
The emergence of variants in recent months has accelerated research on reinforcements. Some variants have mutations that cause them to spread rapidly. Others carry mutations that could reduce the effectiveness of licensed vaccines, but right now, scientists only have a handful of clues as to how existing vaccines work against the various variants.
For example, last month, researchers in Qatar published A study about the Pfizer-BioNTech vaccine, which was administered to more than 250,000 people across the country between December and March.
Clinical trials showed the vaccine was 95 percent effective against the original version of the coronavirus, but a variant called alpha, which was first identified in the UK, reduced its effectiveness to 89.5 percent. A variant first identified in South Africa, known as beta, lowered it further, to 75 percent; however, the vaccine was 100 percent effective against both variants in preventing serious, critical, or fatal disease.
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