Immune evasion variants ensure increasing number of cases
The BA.5 subvariant of SARS-CoV-2 is largely responsible for the current summer wave of coronavirus. The BA.1 and BA.2 sub-variants, which still dominate in the spring, are hardly represented anymore. A new research study now shows why the new subspecies have replaced the old ones.
A working group of the German Primate Center (DPZ) - Leibniz Institute for Primate Research, Hanover Medical School and Friedrich-Alexander-University Erlangen-Nuremberg have found in an ongoing study that infections prior studies with older omicron subvariants BA.1 and BA.2 barely protect against the currently predominant BA.5 subvariant of SARS-CoV-2. Thus, the latter could spread further.
The results of the corresponding study were recently presented in the renowned journal "The Lancet Infectious Diseases".
BA.5 crowds out other coronavirus variants
In Germany and many other countries, the BA.5 subvariant of the SARS-CoV-2 coronavirus replaces the "old" variants BA.1 and BA.2, which were still dominant in the spring of 2022. According to the team of research, the increase in the number of cases in recent weeks is mainly due to BA.5 infections.
Antibodies have little effect on BA.5
The working group showed that therapeutic antibodies and antibodies acquired by vaccination or infections could hardly inhibit the BA.2.12.1, BA.4 and BA.5 sub-variants. Only the bebtelovimab antibody blocked all tested variants with high efficiency.
BA.2.12.1, BA.4 and BA.5 are immune evasion variants
The researchers conclude that BA.2.12.1, BA.4 and BA.5 are immune evasion variants. "It can therefore be assumed that prior infection with BA.1 or BA.2 offers little protection against subsequent infection with BA.4 or BA.5," the scientists write in a press release about the results. of the study.
Lower vaccine protection than older variants
Antibodies acquired by vaccination with BioNTech/Pfizer's mRNA vaccine inhibited all omicron subvariants, but significantly less than the variants that spread early in the COVID-19 pandemic.
“BA.2.12.1 and especially BA.4 and BA.5 are antibody escape variants,” confirms study author Markus Hoffmann. According to him, vaccination still protects against a severe evolution. However, protection is weaker than with previously dominant variants. (vb)
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This text corresponds to the specifications of the specialized medical literature, medical guidelines and current studies and has been verified by health professionals.
Graduate editor (FH) Volker Blasek
Sources:HM. Jäck, GMN Behrens, S. Pöhlmann, M. Hoffmann, et al. : Increased neutralization resistance of emerging omicron subvariants BA.2.12.1, BA.4 and BA.5; in: The Lancet Infectious Diseases (2022) DOI: thelancet.comDeutsches Primatenzentrum - Leibniz Institute for Primate Research: The new omicron subvariants BA.2.12.1, BA.4 and BA.5 are less well inhibited by antibodies (published : 06/30/2022), dpz.eu
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