If the baby is often infected with the virus, it may be a problem of resistance. What are the ways of virus transmission?

Viruses are noncellular forms composed of nucleic acid molecules (deoxyribonucleic acid or ribonucleic acid) and protein. It is an organic species living between parasitic organisms and inanimate organisms. It is neither alive nor inanimate. At present, it is not divided into five realms (prokaryotes, protozoa, fungi, plants and animals)?

It is a piece of deoxyribonucleic acid or ribonucleic acid wrapped in a protective shell. Through the infection mechanism, these simple organisms can replicate themselves by using the host cell system, but they cannot grow and replicate independently. ? Viruses can infect almost all organisms with cellular structure. ? The first known virus is tobacco mosaic virus, which was discovered and named by artinus willem beijerinck in 1899. So far, more than 5000 viruses have been found. ? The science of studying viruses is called virology, which is a branch of microbiology. ?

Viruses are composed of two or three components: viruses all contain genetic material (RNA or DNA, and prions composed only of protein are not viruses); All viruses also have capsids formed by protein, which are used to wrap and protect genetic material. In addition, some viruses can form lipid envelopes when they reach the cell surface.

Viruses come in many forms, from simple helices and icosahedrons to complex structures. ? Virus particles are about 1% the size of bacteria. ? The source of the virus is still unknown. Different viruses may originate from different mechanisms. Some viruses may be derived from plasmids (a kind of cyclic deoxyribonucleic acid that can replicate in cells and transfer between cells), while others may be derived from bacteria. ? Classification by genetic material: deoxyribonucleic acid virus, ribonucleic acid virus and protein virus (such as prion virus) are classified by virus structure; true virus (virus for short) and sub-virus (including sub-virus) are classified by host type: phage (bacterial virus), plant virus (such as tobacco mosaic virus), animal virus (such as avian influenza virus, smallpox virus, AIDS virus, etc. ).) In nature: mild virus (such as HIV), toxic virus (such as rabies virus).