Each winter, three respiratory viruses converge on human populations, demanding separate defenses and separate acts of compliance from the public. A research team has now demonstrated that the biological engineering required to consolidate those defenses into a single injection is achievable — assembling the signature proteins of SARS-CoV-2, influenza A, and RSV onto one hollow particle that the immune system can learn from without ever facing true infection. The result, validated in mice, is less a finished answer than a proof of possibility: that the complexity of nature's threats need not a