Scientists have devised a way to use the antibody-rich blood plasma of COVID-19 survivors for an upper-arm injection that they say could inoculate people against the virus for months. Using technology that's been proven effective in preventing other diseases such as hepatitis A, the injections would be administered to high-risk healthcare workers, nursing home patients, or even at public drive-through sites. But the idea exists only on paper. Federal officials have twice rejected requests to discuss the proposal, and pharmaceutical companies - even acknowledging the likely efficacy of the plan - have declined to design or manufacture the shots. The antibodies in plasma can be concentrated and delivered to patients through a type of drug called immune globulin, or Ig, which can be given through either an IV drip or a shot. Yet for the coronavirus, manufacturers are only developing an intravenous solution of Ig. Intravenous plasma products are traditionally the main economic driver for the industry. The money-making antibodies are also far more diluted in intravenous drugs than in injectable ones, which boosts profit margins. They charge a fortune off of intravenous drugs in the hospital. They don't want to devote the manufacturing plant to something that won't make oodles of money," said one infectious disease expert. Researchers also said industry executives have little incentive to produce the immunity shots for the coronavirus, given the possibility that a longer-lasting vaccine could replace it within a year.