Four million children have yet to be vaccinated against measles, according to Brazilian health officials. Brazil has set a campaign this month to vaccinate children from ages 1-5, but still millions of children failed to get vaccinated as the campaign comes to a close. Brazil has been ranked as one of the lowest vaccinated countries, with over 1,300 people affected by the outbreak.

The disease seems to be linked to Venezuela, one of Brazil’s natural borders and Roraima, two countries with also very low vaccination rates. People have started to flee the neighboring countries, “tens of thousands of them migrating to Brazil,” according to WRAL News; the causation being the collapse of health services thanks to “economic and political turmoil,” making the connection that the measles epidemic was imported from neighboring countries that much easier.

Many have questioned the validity of vaccines, but currently, the Brazilian government will go to any means to stop the measles outbreak.