Order Reprints Print Article Johnson & Johnson says it can make enough doses of its Covid-19 vaccine this year to inoculate almost a billion people against the virus. That would be a massive shot in the arm to the effort to end the pandemic—as long as the vaccine works. Its efficacy should become clear in just a few days. Speaking at an industry conference on Monday,... Close Johnson & Johnson’s Covid-19 Vaccine Could Alter the Course of the Pandemic. Investors Will Soon Know if It Works. Johnson & Johnson says it can make enough doses of its Covid-19 vaccine this year to inoculate almost a billion people against the virus.