By Jennifer Rigby and Julie Steenhuysen LONDON/CHICAGO (Reuters) – Low vaccination rates against the latest versions of COVID-19 and influenza are putting pressure on healthcare systems this winter, leading public health officials told Reuters. In the United States, several European countries, and other parts of the world, there have been reports of rising hospitalizations linked to respiratory infections in recent weeks. Death rates have also ticked up among older adults in some regions, but far below the COVID pandemic peak. Spain’s government has reinstated mask-wearing requirements at heal…