NEJM Study Confirms Continued Efficacy of Certain Antivirals and Monoclonal Antibodies Against Omicron BA.2 Subvariant
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Center Hospital of the National Center for Global Health and Medicine
The Center Hospital of the National Center for Global Health and Medicine actively engages in international cooperation across numerous specialized medical fields, providing advanced, high-quality healthcare services to patients with infectious diseases, chronic conditions such as diabetes and metabolic disorders, and intractable diseases. In collaboration with the Bureau of International Health Cooperation and affiliated research institutes, the hospital offers educational opportunities for interns, researchers, and nurses from around the world, while also delivering medical care to foreigners living and working in Japan. For decades, the hospital has served as a leading institution for postgraduate medical education, conducting comprehensive training programs for clinical trainees, residents, and nurses within Japan; in recent years, it has further expanded its efforts to include the education of undergraduate medical students. Currently, the Nursing Department is implementing a primary nursing system to enhance the professionalism of nursing services and strengthen the continuity of individualized patient care.
National Institute of Infectious Diseases
The National Institute of Infectious Diseases (NIID) of Japan was established in 1947 and adopted its current name in 1997. Its mission is to formulate plans and conduct extensive, original research from the perspective of preventive medicine, thereby enhancing public health and social welfare through the prevention of infectious diseases. It also disseminates scientific knowledge related to national health and medical administration. Its primary tasks include:1. Scientific research, primarily focused on infectious diseases and various refractory conditions related to the immune system. Particular emphasis is placed on molecular biological analysis of pathogens, the development of rapid diagnostic methods and vaccines to address major emerging infectious diseases that threaten human health, as well as certain re-emerging traditional diseases. The institute also conducts research on vectors for gene therapy, which has gained prominence in recent years, along with safety assessments. Currently, key areas of infectious disease research include HIV/AIDS, tuberculosis, and malaria.2. Consultation services for various infectious diseases, including all advisory services required to maintain the infectious disease testing system. Specific services encompass the storage and provision of pathogens, standardization of diagnostic reagents, provision of data necessary for diagnosis and surveillance, and facilitation of relevant information exchange. An information network system is jointly established with local public health institutions.3. Surveillance of infectious diseases, including the collection, analysis, and dissemination of information.4. National testing for infectious disease control and other related tests.5. International cooperation.6. Relevant training programs.
University of Tokyo
The University of Tokyo is Japan’s first national comprehensive university. As a leading research-intensive institution, it offers undergraduate and graduate programs across all academic disciplines and conducts research spanning the full spectrum of scholarly inquiry. Currently, the University comprises 10 faculties, 15 graduate schools, 11 affiliated research institutes (including the Research Center for Advanced Science and Technology), 13 university-wide research centers, 3 affiliated libraries, and 3 advanced research institutes. In addition, each faculty, graduate school, and research institute maintains its own related affiliated organizations.
University of Wisconsin
The University of Wisconsin is a state university system in the U.S. state of Wisconsin, with a long history spanning over 170 years. Its flagship institution, the University of Wisconsin-Madison, is located in Madison, the capital of Wisconsin, on the western shore of Lake Michigan.The term "University of Wisconsin" generally refers to the University of Wisconsin-Madison, located in Madison, the capital of Wisconsin. Like other renowned American public universities such as the University of California and the University of Texas, the University of Wisconsin is a university system composed of multiple state universities, known as the "University of Wisconsin System." The University of Wisconsin System consists of ten public universities distributed across Wisconsin. The University of Wisconsin in Madison is the birthplace of the University of Wisconsin System, the first university in Wisconsin, and the flagship of the system, enjoying widespread prestige.
News on March 14, 2022 / BIOON / ---In a new study, researchers from Japan's National Institute of Infectious Diseases, Japan's National Center for Global Health and Medicine, the University of Tokyo, and the University of Wisconsin-Madison in the United States found that the antiviral drugs remdesivir, molnupiravir, and nirmatrelvir, the active ingredient in Pfizer's Paxlovid tablets, remained effective against the Omicron BA.2 subvariant of SARS-CoV-2 (the coronavirus that causes COVID-19) in laboratory tests.The relevant research findings were published online in the NEJM journal on March 9, 2022, with the paper titled "Efficacy of Antiviral Agents against the SARS-CoV-2 Omicron Subvariant BA.2”。
The BA.2 subvariant also remains sensitive to at least some monoclonal antibodies used to treat COVID-19, such as AstraZeneca's Evusheld (a combination of tixagevimab and cilgavimab). However, in these laboratory tests, the antibodies etesevimab and bamlanivimab, used together as a single therapy, were unable to neutralize the BA.2 subvariant at standard doses. Other antibody therapies are less effective against BA.2 compared to earlier strains of SARS-CoV-2.
Efficacy of Monoclonal Antibodies and Antiviral Drugs Against the Omicron/BA.2 Subvariant In Vitro. Image from NEJM, 2022, doi:10.1056/NEJMc2201933.
Omicron BA.2 Subvariant Shares a Close Relationship with the More Common Omicron BA.1 Subvariant, and Some Evidence Suggests That BA.2 Can Spread Faster Than the Already Highly Contagious BA.1.
"The bottom line is that we have antibodies that seem to be more effective against BA.2 compared to BA.1 or BA.1.1. This is good news, but we don't know if what we found in the lab will translate into clinical use," said Yoshihiro Kawaoka, corresponding author of the paper from the University of Tokyo. "We also tested clinically available antiviral compounds, and they all worked well." Kawaoka had previously tested the BA.1 subvariant for its response to treatment.
In laboratory experiments using non-human primate cells, the Kawaoka team tested the efficacy of seven monoclonal antibodies, three antibody combinations, and three antiviral drugs against the BA.2 subvariant. Most clinically approved antibody drugs involve the combined use of multiple antibodies.
The active ingredients of the intravenous drug Remdesivir and two anti-COVID-19 pills—Pfizer's Paxlovid and Merck's Molnupiravir—and their effects on BA.1 are almost the same as their effects on the original SARS-CoV-2 strain. The most effective antibody drug against the BA.2 subvariant is Evusheld, which is authorized in the U.S. to help prevent infection with this subvariant in people at high risk of severe disease. Anti-COVID-19 antibodies sold by Regeneron in the U.S. and GlaxoSmithKline in the U.K. work much better against BA.2 than against the BA.1 subvariant, although their efficacy against BA.2 is not as strong as it is against earlier versions of the virus.
Existing anti-COVID-19 treatments are generally less effective against new variants than against the original SARS-CoV-2 strain, as they were designed and tested for earlier versions of SARS-CoV-2. Scientists and pharmaceutical companies can design and test treatments targeting new variants, but this process takes several months. (Bioon.com)
References:
Emi Takashita et al. Efficacy of Antiviral Agents against the SARS-CoV-2 Omicron Subvariant BA.2. NEJM, 2022, doi:10.1056/NEJMc2201933.