Vaccinations are an effective and important way to prevent widespread infections that can cause potentially deadly disease and pandemics. It is a global health success story that helped eradicate outbreaks of diseases such as measles, polio, and specific strains of influenza. The first immunization practice occurred hundreds of years ago. In 17th century China, Buddhist monks gained immunity to smallpox by drinking snake venom. In 1796, immunizations were brought to the west by Edward Jenner, considered the founder of vaccines. He developed the first smallpox vaccine in 1798. In the 1920s, Alexander Glenny developed the tetanus vaccine when he discovered the substance that could be used to inactivate the tetanus toxin, making it safe to be inoculated into the body. Today, medical advances have included the use of molecular genetics to create vaccines. Vaccines can deliver DNA, viral vectors, and select bacterial and viral particles to confer immunity without causing disease in the recipient.
Vaccination of children starts from birth. The first vaccine a child receives is usually the hepatitis B vaccine. The first dose is given shortly after birth, and subsequent doses are given in the first year of life. Hepatitis B is a virus that can be transmitted through bodily fluids or blood. Hepatitis B infection can acutely cause fever, jaundice, abdominal pain, weakness, and joint pain. Long term complications include liver failure and liver cancer.
An early childhood vaccine can protect against chickenpox. The virus that causes it is highly contagious, being spread through the air by respiratory droplets and by physical contact with an infected person. Chickenpox can spread quickly in households and daycare centers in susceptible individuals. Symptoms include whole body rash, blisters, intense itchiness, brain swelling, and pneumonia.
The MMR vaccine is gtiven to people for measles, but it also serves as the vaccine for mumps and rubella. Measles has largely been eradicated from the U.S. population due to widespread vaccination and herd immunity. Small outbreaks have been reported in groups that refuse vaccinations for their children. Measles cause fever, runny nose, cough, and rash. Severe cases can result in brain swelling, pneumonia, and death. Mumps can cause swollen parotid gland, fever, headache, muscle pain, meningitis, inflammation of the gonads, and permanent deafness. Rubella in pregnant women can lead to miscarriages and birth defects.
The influenza vaccine is approved for use in children aged 6 months older and is recommended yearly. Each year, hundreds of children in the U.S. die from complications of the flu. Infection with influenza virus can cause mild symptoms such as fever, cough, and runny nose, but can also cause severe pneumonia and death. Children who are unvaccinated are at risk of catching the flu and even if they recover well, can spread it to more vulnerable people such as their grandparents.
Some vaccines can prevent cancer, such as the HPV vaccine and the hepatitis B vaccine. As discussed earlier, the hepatitis B vaccine can prevent liver cancer. The HPV vaccine is given to both boys and girls starting in early adolescence. HPV is a sexually transmitted virus that can cause cervical, vaginal and vulvar cancers in women, and anal cancer in men. Certain types of HPV can also cause genital warts.
Vaccines can even be used to treat cancer. Many of these are new and still being studied in clinical trials. Immunotherapy is using vaccines to deliver cancer-specific antigens to the body, so that cancer cells are tagged. The immune system can then attack cells with cancer-specific antigens, leaving healthy cells alone. One such vaccine was approved by the FDA in 2010 to treat people with metastatic prostate cancer. The BCG vaccine is used to treat bladder cancer.
Immunizations work at both an individual and population level. At the individual level, vaccines work because they expose the body to inactivated parts of viruses or bacteria. The immune system is primed to recognize these vaccine particles and create white blood cells and antibodies that are ready to fight in the event a live virus or bacteria is encountered. On a population level, mass vaccination creates herd immunity. Viruses and bacteria are unable to spread and cause outbreaks because even if one person is infected, the majority of the population is immune from vaccinations. This helps keep the disease under control. Since the advent of vaccines, life expectancies have increased throughout the world and complications from once deadly infections have decreased.
We just love sending fun emails!