B561B

B561B is a designation that can refer to several different entities, most notably a specific strain of poliovirus and a model number for electronic components.

As a poliovirus strain, B561B is a type 2 attenuated strain. Attenuated strains are weakened forms of a virus used in vaccines, designed to stimulate an immune response without causing disease. Type 2 poliovirus was historically a component of the oral polio vaccine (OPV), though its use in routine vaccination has been phased out in many regions due to the risk of rare vaccine-derived poliovirus (VDPV) emergence. Research on such strains is crucial for understanding viral evolution and developing safer vaccination strategies.

In the realm of electronics, B561B can appear as a part number or designation for various components. This often relates to capacitors, specifically ceramic capacitors. For instance, it might indicate a capacitor with a certain capacitance value, tolerance, and voltage rating, manufactured by a specific company. The exact specifications would be detailed in the manufacturer's datasheet. Identifying the precise component requires context, such as the manufacturer's name or the electronic device in which it is found.