human metapneumovirus hmpv

metapneumovirus pneumoviridae transmission circulation respiratory background bronchitis prevention awareness detection diagnosis pneumonia structure syncytial treatment undefined epidemic isolated outbreak pandemic protocol response symptoms climate concept disease droplet protein medical asthma change common corona fusion immune season severe sneeze system black cough covid human virus cold cure germ hmpv rise flu rsv presentation advertising screenshot cartoon poster flower orange person brand organ plant petal font text logo red art