Sufficient neutralizing antibodies effective against Omicron strains cannot be obtained without booster vaccination

An infected person who seems to be the first case of community-acquired infection in Japan of the mutant strain 'Omicron strain' of the new coronavirus was confirmed. While it is thought that the Omicron strain has fewer serious symptoms than the mutant strains so far, the vaccine may be less effective, and there is concern about the explosive spread of the infection. Studies have shown that each company's vaccines do not provide

sufficient neutralizing antibody levels to prevent the Omicron strain with just one or two doses without booster vaccination.

mRNA-based COVID-19 vaccine boosters induce neutralizing immunity against SARS-CoV-2 Omicron variant | medRxiv

The 'Omicron strain' is one of the variants of the new coronavirus that has been rampant in the world since early 2020, and was

discovered in South Africa in November 2021.

Compared to the Delta strain, which was a global epidemic until the fall of 2021, the Omicron strain is characterized by less severe and less severe symptoms. Studies show that the risk of hospital visits is 20% to 25% lower and the risk of temporary hospitalization is 40% to 45% lower. Even those who have not been infected with the new coronavirus in the past, have not been vaccinated, and do not have antibodies are at 11% lower risk of hospitalization than the Delta strain.

Report 50 --Hospitalization risk for Omicron cases in England | Faculty of Medicine | Imperial College London

On the other hand, the infectivity is extraordinarily strong, and the mainstream has already shifted from the Delta strain to the Omicron strain in the United Kingdom. It has been suggested that the effect of the vaccine on Omicron strains is also smaller than that on other mutant strains.

Regarding this, Moderna has announced that booster vaccination (booster vaccination) will increase the neutralizing antibody level by 83 times, and that the same effect as the previous mutant strain will be obtained for the Omicron strain. Pfizer has also announced that boosters will increase antibody levels by a factor of 25.

Antibodies increased by '83 times' by booster inoculation of Moderna vaccine, and preventive effect of Omicron strain is also confirmed --GIGAZINE

Studies by Massachusetts Institute of Technology, Massachusetts Institute of Technology, Harvard University, etc. support this, and the serum of people who have been vaccinated once or twice with Pfizer, Moderna, and Johnson End Johnson can be used to prevent Omicron strains. It was not possible to confirm sufficient antibody levels.

For this reason, booster vaccination is considered to be important as a countermeasure against Omicron strains.

in Science, Posted by logc_nt