New variant of "Deltacron" virus? The third dose is 30 times less protective? Experts reveal the key to epidemic situation
How important is the third dose of vaccine to boost the body’s immunity and avoid the risk of severe illness and hospitalization? A study just published in the New England Journal of Medicine (NEJM) pointed out that the new coronavirus booster shot (the third dose) provides antibody protection against Omicron subtypes of viruses, including BA.2, BA.3 and the hybrid virus with Delta “Deltacron” “, the benefits are broader than the second dose of the vaccine, and the study also calls on those who have not been vaccinated to complete the vaccination measures as soon as possible.
American research reveals that the “third dose” has the most comprehensive protective effect on BA.2, BA.3, and Deltacron
The Ohio State University Wexner Medical Center tested the serum antibody levels of 10 health care workers. On average, after two vaccinations, the antibody concentrations against BA.3 and Deltacron were 3.3 times and 44.7 times lower than those against the original strain, respectively. After the third dose of vaccine, the antibody concentration decreased by 2.9-fold and 13.3-fold, showing a significant improvement in the protective effect, especially against Deltacron, with a difference of about 30-fold.
Another study published in “Cell Host & Microbe” tested the serum antibody concentrations of 48 health care workers after receiving the second dose of the mRNA vaccine, and 19 after receiving the third dose of the mRNA vaccine, and compared 31 Omicron Serum antibody concentrations of hospitalized patients during the epidemic served as controls.
The study pointed out that the neutralizing antibody concentration against the Omicron variant was “very weak” in subjects who received two doses of the vaccine, but after the third booster dose, the neutralizing antibody concentration gradually leveled off. Compared with the original strain, although the concentration of neutralizing antibodies against Omicron is lower and it is easier to cause “immune escape”, the third dose undoubtedly provides broader protection and significantly reduces the risk of severe illness and hospitalization.
“Whether patients are suffering from Delta, Deltacron or Omicron, if they receive a booster shot, they will be protected to some extent. Subjects who received 3 doses of the vaccine generally had the broadest and strongest antibody protection.” Study author John Evans It said that the third dose of the vaccine can produce a high enough concentration of antibodies to protect against BA.2; this shows that variants before Omicron-BA.3 are difficult to cause large-scale infections when the third dose is widely administered to people.
New Omicron variant is coming fiercely Experts: The virus’s “3 characteristics” may lead to a new wave of pandemic
However, the mutation of Omicron virus continues non-stop. An experiment recently published by John Evans and study co-author Shan-Lu Liu on the preprint “BioRxiv” pointed out that although the third dose provided a certain degree of antibody concentration against new variants such as BA.2.12.1, BA.4 and BA.5 , but the level is lower than that of the first generation BA.1 and BA.2. Liu explained that future research should begin to focus on how long the antibody protection of the third dose lasts.
“Viruses are evolving, so anything can happen, including recombination between mutant viruses, such as Deltacron, which combines the powerful pathogenicity of Delta with the immune evasion ability of Omicron. Therefore, the best way to protect against viruses is currently , that is, administering the full three doses of vaccine as soon as possible; and two doses of vaccine are absolutely necessary for the current Omiron epidemic,” Liu said.
Jesse Bloom, an American virus evolutionary biologist, also expressed his opinion on the BA.4 and BA.5 subtypes, pointing out that they seem to be more transmissible and seem to be better able to evade than BA.1, BA.2 and BA.3. Antibodies and immune responses mean that the virus may significantly increase the risk of “secondary infection” for infected people. This indicates that there may be a new wave of epidemics in the world in the future, and relevant health authorities need to treat it with a more rigorous attitude.
Therefore, Bloom reminds the public that they should not overly ignore the Omicron epidemic. Even though most of the confirmed cases at this stage are mild, they still need to take preventive measures in daily life, such as washing hands frequently, maintaining social distance, and avoiding indoor confined spaces or crowded places. .
source:
Neutralization of the SARS-CoV-2 Deltacron and BA.3 Variants
Neutralization of SARS-CoV-2 Omicron sub-lineages BA.1, BA.1.1, and BA.2
Excess Mortality in Massachusetts During the Delta and Omicron Waves of COVID-19
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