The Vatican's new ruling on condom use is being questioned by conservative elements of the Catholic church.
Prominent Catholics in the US are rejecting its own explanation of what the pope said and several said they would only accept a more formal papal pronouncement.
Others insisted that journalists were purposely misrepresenting the pope's comments. Some questioned whether the papal spokesman, the Rev. Frederico Lombardi, accurately quoted the pope.
Bishops and the experts who advise them were trying to make sense of the news.
"It's a mess," said John Haas, president of the National Catholic Bioethics Centre in Philadelphia, which advises church leaders, hospitals and Vatican offices. "I'm not ready to say that the pope said what Lombardi said."
The uproar is over comments the pope made in the new book, Light of the World: The Pope, the Church and the Signs of the Times. In an exchange with the author about Aids in Africa, he said that for some people, such as male prostitutes, using condoms could be a step in assuming moral responsibility because the intent is to "reduce the risk of infection".
At a news conference in Rome, Mr Lombardi said the pope knew his comments would provoke intense debate, and that he meant his remarks to apply not just to male prostitutes, but also "if you're a man, a woman, or a transsexual."
The pope did not suggest using condoms as birth control, which is banned by the Roman Catholic Church, and said condoms were not a "real or moral solution" to the Aids crisis. However his remarks were a watershed in the long debate among theologians and church officials over the morality of using condoms for disease prevention.
Jenn Giroux, executive director of Human Life International America, which promotes Catholic teaching on contraception, abortion and other moral issues, said more clarification from the Vatican was needed. "I am watching very carefully, as everyone is right now, before making a final pronouncement," said Mrs Giroux. "We just got something from a spokesperson. As always, we look to church doctrine on statements like this."
The pope's comments in a book interview do not amount to an official teaching, a point conservative Catholics have made repeatedly and vociferously. They argued that the pope was only noting that by using a condom, a person with HIV is displaying some moral sense about the consequences of his behaviour.