More than 85 per cent of Hong Kong infants and toddlers remain unvaccinated against the flu, as medical experts urge broader immunisation against respiratory viruses, citing a higher risk of co-infection among high-risk groups this winter. Experts on Sunday warned that if the summer flu peak extends and overlaps with the winter season, respiratory viruses could remain highly active for an extended period. They urged the public to get vaccinated against both influenza and respiratory syncytial...