Many nations battling the Zika virus have large Catholic populations, and Pope Francis has finally spoken: During an overnight flight back to Rome on Wednesday, he shared some monumental news — contraception could be justified in Zika-affected nations.

This is an unprecedented move for the Catholic Church. The religion’s leaders are notorious for upholding draconian laws against condom use and other forms of birth control, even in light of devastating sexually transmitted diseases such as HIV.

Fears that infected mothers will give birth to infants with microcephaly have prompted nations to propose a two-year ban on pregnancies. This sparked vehement backlash from critics who argue it’s impossible to avoid pregnancy when birth control is unavailable and sexual violence is rampant.

Bishops in Zika-stricken countries such as El Salvador, lacking instructions from the Vatican on how to proceed, have remained reticent. The Church has always responded to criticism by championing “natural family planning” — that is, scheduling sex according to a woman’s menstrual cycle to prevent pregnancy — in place of artificial contraceptives.

But the Pope, returning from a six-day trip to Cuba and Mexico, said that the spread of Zika was an exceptional circumstance that could justify using artificial birth control.

“Avoiding pregnancy isn’t an absolute evil, and in certain cases such as this one, as in that one I mentioned of Blessed Paul VI, it was clear,” Francis said, referring to a previous Pope who, in 1968, claimed it was permissible for nuns in danger of being raped to use birth control.

Francis did, however, make sure to differentiate between contraception — permissible in these highly irregular circumstances — and abortion, which he asserted is never acceptable.

The Pope’s comments are likely to ease tension in Latin American countries where avoiding pregnancy has been difficult, but they do not offer guidance for women who are already pregnant and likely to give birth to an infant with microcephaly.

Photos via Franco Origlia/Getty