Well, think of WHO as the 'least bad source of information", not the absolute truth provider. To get closer to the truth, you’d need to do a bit of journalist work: do a background check on the scientists involved (what have they published? Is their work respected by their peers? Have they been approached by lobbies?) and compare different sources (for instance, look at what the Robert Koch Institut in Germany and the Institut Pasteur in France have to say). But, to do that you might need to speak several languages, but above all, you would need a lot of time for research. So checking the most reliable source is generally the practical course of action for most people.