Many things have changed since the start of the pandemic, but the very first piece of advice is still very much in place: wash your hands. We’re still not sure just how the coronavirus spreads, but washing your hands is a cheap, low-effort intervention.

But for many people, that’s not exactly the case. According to UNICEF data, 2 out of 5 people worldwide don’t have access to basic handwashing facilities. Pandemic or no pandemic, that’s a huge problem.

It might not get much credit in the developed world, but handwashing is one of the most critical tools in the fight against all infectious diseases. It’s simple enough, you just need two things (which, let’s face it, most of us take for granted): water and soap.

But for a disturbingly large number of people around the world, those two things are not readily available.

Worldwide, 780 million people do not have reliable access to a clean water source (as of 2017, the latest available report). Another disturbing report notes that 2.5 billion people lack access to improved sanitation (more than 35% of the world’s population). When you also consider soap availability, it comes up to 3 billion people (or 40% of the world’s population) that don’t have a handwashing facility with clean water and soap at home.

It’s not just houses, either. According to the World Health Organization, 2 in 5 schools around the world lacked basic handwashing facilities prior to COVID-19 (there is no reliable estimate for during the pandemic); that makes for 900 million school-age children that are left exposed.

“Handwashing with soap is one of the cheapest, most effective things you can do to protect yourself and others against coronavirus, as well as many other infectious diseases. Yet for billions, even this most basic of steps is simply out of reach.” said Sanjay Wijesekera, UNICEF Director of Programmes. “It is far from a magic bullet. But it is important to make sure people know what steps they should take to keep themselves and their families safe, even as we continue our longstanding efforts to make basic hygiene and sanitation available to everyone.”

This lack of basic hygiene facilities translates into a massive disease burden. Every year, millions of people are infected with neglected tropical diseases (NTDs) such as Guinea Worm Disease, Buruli Ulcer, Trachoma, and Schistosomiasis, which are believed to be water and/or hygiene-related. Soil parasitic worms infect a billion people every year, and gastrointestinal infections such as diarrhea kill over 2 million people every year (including half a million children).

While the figure has been decreasing in recent years, there is still a lot of ground to cover. Studies have shown that access to clean water and soap could cut the number by more than60%.

Then, there’s the pandemic.

It’s hard to imagine too many coronavirus protective measures for the 8 million urban Filipinos that lack handwashing facilities at home; or the 258 million urban dwellers in sub-Saharan Africa; or the 153 million in cities in south and central Asia. The virus itself may affect us all equally, but the way we can prepare against it is anything but equal. If anything, the pandemic is accentuating social inequities rather than erasing them.

There are encouraging signs. Around 2.1 billion people have gained access to basic sanitation since 2000 — but that shouldn’t be taken for granted. In many parts of the world, this new sanitation is wasteful, unsafe, or unsustainable.

The world could be using the pandemic as an opportunity to finally prioritize basic hygiene in all corners of the world. If anything, the economic case for investments in drinking water, sanitation, and hygiene services is clearer than ever: every dollar invested will return $2.5 in saved medical costs and increased productivity. With the pandemic in our faces, that return figure has certainly increased.

“Closing inequality gaps in the accessibility, quality and availability of water, sanitation and hygiene should be at the heart of government funding and planning strategies. To relent on investment plans for universal coverage is to undermine decades worth of progress at the expense of coming generations,” remarked Kelly Ann Naylor, UNICEF Associate Director for Water, Sanitation and Hygiene.

Meanwhile for those of us that do have access to basic sanitation, it’s a simple reminder to wash our hands — during the pandemic, and after. It’s a luxury many don’t have.