Who is John Campbell?My name is John Campbell. I am a retired Nurse, Teacher, and A&E nurse based in England. I also do some teaching in Asia and Africa when time permits. These videos are to help students to learn the background to all forms of health care. My PhD focused on the development of open learning resources for nurses nationally and internationally.
What is Vaccine?A vaccine is a biological preparation that provides active acquired immunity to a particular infectious disease. A vaccine typically contains an agent that resembles a disease-causing microorganism and is often made from weakened or killed forms of the microbe, its toxins, or one of its surface proteins. The agent stimulates the body's immune system to recognize the agent as a threat, destroy it, and to further recognize and destroy any of the microorganisms associated with that agent that it may encounter in the future. The administration of vaccines is called vaccination. Vaccination is the most effective method of preventing infectious diseases; widespread immunity due to vaccination is largely responsible for the worldwide eradication of smallpox and the restriction of diseases such as polio, measles, and tetanus from much of the world.
What is mRNA?mRNA or messenger RNA, in molecular biology is a single-stranded molecule of RNA that corresponds to the genetic sequence of a gene, and is read by a ribosome in the process of synthesizing a protein. During transcription, RNA polymerase makes a copy of a gene from the DNA to mRNA as needed. This process is slightly different in eukaryotes and prokaryotes, including that prokaryotic RNA polymerase associates with DNA-processing enzymes during transcription so that processing can proceed during transcription. As in DNA, genetic information in mRNA is contained in the sequence of nucleotides, which are arranged into codons consisting of three base pairs each. Each codon codes for a specific amino acid, except the stop codons, which terminate protein synthesis. The translation of codons into amino acids requires two other types of RNA: transfer RNA, which recognizes the codon and provides the corresponding amino acid, and ribosomal RNA (rRNA), the central component of the ribosome's protein-manufacturing machinery.