By Jennifer Rigby LONDON (Reuters) -If rich nations think the pandemic is over, they should help lower-income countries reach that point too, a senior World Health Organization official told Reuters. In an interview, WHO senior adviser Bruce Aylward warned that richer nations must not step back from tackling COVID-19 as a global problem now, ahead of future potential waves of infection. In the last few weeks, WHO Director General Tedros Adhanom Ghebreyesus said the end of the pandemic was in sight, and U.S President Joe Biden said the pandemic was over. “When I hear them say, ‘Well, we’re so c…