This Sept. 2020 photo provided by Johnson & Johnson shows the investigational Janssen COVID-19 vaccine. Johnson & Johnson’s long-awaited COVID-19 vaccine appears to protect against symptomatic illness with just one shot – not as strong as some two-shot rivals but still potentially helpful for a world in dire need of more doses. Johnson & Johnson said Friday, Jan. 29, 2021 that in the U.S. and seven other countries, the first single-shot vaccine appears 66% effective overall at preventing moderate to severe COVID-19. It was more protective against severe symptoms, 85%. (Cheryl Gerber/Johnson & Johnson via AP) The Biden administration is purchasing an additional 100 million doses of Johnson & Johnson’s coronavirus vaccine, the White House announced Wednesday. President Biden is expected to announce the federal government’s purchase during an event at the White House later Wednesday with the heads of Johnson & Johnson and Merck, during which the president is set to reveal he is instructing the Department of Health and Human Services (HHS) to secure the additional vaccine doses. “This order allows for the president to plan for the future and the latter part of the year,” Andy Slavitt, White House senior adviser for COVID-19 response, said during a briefing by the White House COVID-19 Response Team. “This is war time, and as facts still emerge, it gives us maximum flexibility for our upcoming needs.” The two pharmaceutical companies announced earlier this month they would be partnering to boost production of Johnson & Johnson’s single-dose coronavirus vaccine. Merck is expected to dedicate two factories to producing the shot. Mr. Biden has set a goal of ensuring the country administers at least 100 million vaccinations in his first 100 days in office, and his administration has continued to increase the federal government’s supply of doses to accelerate that goal. Last month, HHS announced it purchased 200 million more doses of COVID-19 vaccines from Pfizer and Moderna, which each require a two-shot regimen. The administration’s order brought the total doses bought by the federal government from the two companies to 600 million, enough to fully vaccinate 300 million people, most of the U.S. population. The recent federal authorization of Johnson & Johnson’s vaccine for emergency use is expected to further speed up vaccinations in the U.S., and Mr. Biden announced this month the nation will have enough vaccines to cover all adults by the end of May. More than 93.7 million vaccine doses have been administered as of Tuesday and 123.2 million shots have been delivered, according to the Centers for Disease Control and Prevention. More than 32 million Americans are fully vaccinated, and the U.S. is now averaging more than 2 million shots administered per day.