[Quartz] The omicron variant is spreading fast. According to the World Health Organization, at least 38 countries, on six continents, have confirmed cases of the new variant. There is still quite a bit we don’t know about omicron—including whether it is more contagious than delta, and if it is more likely to escape vaccine protection.

So far, we have some indications that both conditions might be true, and that omicron appears to present a higher risk of reinfection for people who already had covid-19. At the moment, delta—which is more contagious than previous variants—is still the prevailing variant around the world, and with omicron increasing and winter underway in the northern hemisphere, it’s again time to mask up properly.

In other words, you might want to put away your cloth masks and turn to N95.