Facebook CEO Mark Zuckerberg has come out swinging in support of vaccination--and he wants his book club members to read all about it. Undaunted by lukewarm reception to his first few picks, Zuckerberg is continuing with his public new year's resolution to read a new book every two weeks with a fourth choice, On Immunity: An Inoculation, by essayist Eula Biss.

The book club, called "A Year of Books," has had growing pains, including a dismally-attended Facebook Q&A with the first book’s author who was asked many questions from folks who hadn’t read the book, the Washington Post reported. It seems Zuckerberg has learned a few things about picking a book that will engage, but not overwhelm, readers: On Immunity is short, sweet, is recommended by plenty of health professionals, and fits within Zuckerberg’s stated goal to educate his book club followers in economics, psychology, and sociology.