Omicron countdown?

January 18, 2022 / eMedClub News/--Recently, South Africa’s official agency announced that South Africa has passed the peak of Omicron without a significant increase in mortality
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A UK government report published on 31 December 2021 found that about half of those infected with Omicron in England required hospitalisation or emergency care as those infected with Delta
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▲ The infection of the South African variant strain peaked and then declined (Image source: Reference 1) New clinical evidence explains why Omicron is less virulent than before, and the virus preferentially affects the upper respiratory tract rather than substantial lung replication and lesions
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 In December last year, scholars at the University of Hong Kong found that Omicron mainly replicates rapidly in the human bronchi, compared to Delta's damage to the lungs
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In January, a study on a BioRxiv preprint also claimed that the virus infects the lungs less so than the bronchi and integrates directly into cell membranes (previous mutants relied on a protein)
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However, with the increase in the number of vaccinations, the immune protection of the population itself has been improved
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Therefore, it is difficult for us to judge the effective role of the new crown vaccine when new variants appear, and what role can anti-epidemic measures such as booster needles play in it? mRNA boosters induce neutralizing immunity against Omicron Current vaccines against Omicron variants have been reported to be less protective compared to the previous worrisome variant (VOC), but they may still provide some protection
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Studies have shown that 2 doses of mRNA vaccine have poor neutralization effect on the Omicron variant, while the third dose of mRNA vaccine can boost immunity to increase protection
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Cell published the article "mRNA-based COVID-19 vaccine boosters induce neutralizing immunity against SARS-CoV-2 Omicron variant" by the Ragon Institute and Harvard Medical School on January 6, describing mRNA-based COVID-19 19 Vaccine boosters induce neutralizing immunity against Omicron variants
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▲ Image source: Cell magazine researchers measured serum neutralization of SARS-CoV-2 wild-type pseudovirus, SARS-CoV-2 wild-type pseudovirus, 88 mRNA-1273 vaccinees, 111 BNT162b vaccinees, and 40 Ad26.
COV2.
S vaccinees.
and the potency of its variants Delta and Omicron pseudoviruses
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We recruited three groups of vaccine recipients with different timing of vaccination: recent (<3 months) vaccine recipients, long-term (within 6-12 months) vaccine recipients, "booster" dose recipients, and Whether these vaccine recipients had been previously infected with SARS-CoV-2 was considered
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Notably, neutralization against the Omicron variant was undetectable in most vaccine recipients
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However, the results showed that the mRNA vaccine booster had potent neutralization against the Omicron variant in vivo, and the neutralization response was only 4-6 times lower than that against the SARS-CoV-2 wild-type virus, This indicates enhanced cross-reactivity of neutralizing antibodies
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Development of a specific vaccine against Omicron In conclusion, current COVID-19 vaccines are not as effective against Omicron variants as they were for previous VOCs
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Therefore, the development of specific vaccines based on mutant mutants of the spike protein, especially against mutants of Omicron, may be another strategy
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Studies have also demonstrated that infection with the Omicron variant can induce a wider range of neutralizing antibodies, which can be used to immunize other variants of the new coronavirus
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Pfizer developed a vaccine specifically for omicron by March
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A hybrid vaccine will also be launched that will protect against omicron and other COVID-19 variants, and Pfizer submitted clinical data for its drug Paxlovid on Dec.
1, 2021, and is currently undergoing final review by Canadian regulators
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▲ The mutant strain reached its peak and then decreased (Image source: Reference 1) On the one hand, Moderna tested the effectiveness of the previous vaccine against Omicron, including the detection of the neutralizing activity of mRNA-1273 vaccine sera for Omicron.
In the data, only a half-dose booster boosted the level of neutralizing antibodies by 37 times, enough to fight Omicron; on the other hand, a vaccine mRNA-1273.
529 against B.
1.
1.
529 is also being developed to deal with other situations that may arise
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▲ mRNA-1273.
529 targeting Omicron in Moderna’s pipeline (Source: Moderna’s official website) At present, the epidemiological characteristics of Omicron variants are becoming clearer
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Given that the same mutation was observed in the spike protein of previous VOCs, it is suggested that current public health measures, including maintaining ventilation, maintaining a safe distance, frequent hand washing, and wearing a mask, are also effective against the Omicron variant
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Reference: 1.
https:// P, KIRPICH A, BAYKAL PI, et al.
Global transmission network of SARS-CoV-2: From outbreak to pandemic[J].
MedRxiv , 2020:32511620.
3.
Fuzhou City Big Data Commission "China's first international peer-reviewed vaccine booster vaccination against Omicron data released: fate is still in the hands of human beings"