Yes, through modern bioengineering techniques, scientists can synthesize new strains of viruses, including those that do not exist in nature. This process often involves synthetic biology techniques, in which scientists design and make new gene sequences. These gene sequences can be inserted into the genome of an existing virus, or used to build entirely new viruses. This research may be used for a variety of purposes, including vaccine development, gene therapy, and studying viral behavior. However, the potential risks of this work are very high, as viruses with unexpected properties or pathogenicity may be produced. Therefore, research into synthesizing new viruses is usually subject to strict regulation and ethical review to ensure its safety and scientific value.