Last month, as reports of a Zika virus outbreak in Rajasthan spread, so too did fear for the then-25 infected pregnant women (the number has now risen to 64); in Brazil, the virus was responsible for a rash of babies born with microcephaly, a birth defect characterized by an unusually small, underdeveloped head. Now, however, scientists from National Institute of Virology in Pune have determined that the Zika strain responsible for India’s outbreak is slightly different from the Brazilian strain in one key way.

“The good news is that this mutation associated with microcephaly is not found in strains of Zika virus that has infected persons in Jaipur,” Dr Balram Bhargava, the director general of the Indian Council of Medical Research (ICMR), told The Indian Express. All but four of the 163 reported cases of Zika virus in India are located in Jaipur.

A team of scientists arrived at this conclusion after sequencing the full genome of the Indian strain. However, this finding does not fully eliminate the risk of microcephaly in babies born to women who have had a Zika infection while pregnant; Bhargava notes that many other factors might contribute to microcephaly, and that the pregnant, female Zika patients are being closely observed.

As The Swaddle reported earlier, Zika infection, spread by the same mosquitoes responsible for chikungunya and dengue, is notoriously difficult to diagnose, in part because it causes only mild flu- or dengue-like illness, or no symptoms at all. There is no vaccination for it, and because it is viral, rather than bacterial, antibiotics cannot be used to treat it; instead, doctors can only prescribe rest, drinking enough fluids, and controlling pain and fever with common, over-the-counter medicines.

So, while the news that the microcephaly-causing gene is absent from India’s Zika strain is reassuring, experts still advise pregnant women to guard against mosquito bites in the same ways they’ve always avoided other mosquito-borne illnesses like malaria or dengue.