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Childhood immunization has become a heated topic of debate in this country. Medical experts in immunology and pediatrics emphatically recommend immunizations (or vaccinations) for all children. Their advocacy for immunization is based on massive amounts of data (available from the U.S. Centers for Disease Control and Prevention at www.cdc.gov) that show marked decreases in the incidences of many diseases (and complete eradication of others) in infants, children and adults since the practice of immunization started. Just last month, a special federal court ruled that there was no link between a the MMR (measles-mumps-rubella) vaccine and the development of autism.
Opponents of immunizations claim that immunizing children has lead to an increase in the incidence of autism. Many parents insist that after their children received a round of immunizations, they became withdrawn, listless, stopped communicating and seemed to stop or regress developmentally. They believe that mercury used as a preservative (in the form of thimerosal) caused the regression in their children. Mercury is toxic to the central nervous system and leads to brain and nerve tissue degeneration and destruction. Because of the public outcry, the U.S. Food and Drug Administration worked with pharmaceutical companies to reduce and/or eliminate thimerosal and other mercury containing substances from vaccines. As of 1999, most vaccines don’t contain thimerosal or mercury. Very few, such as the inactivated influenza vaccine, contain very trace amounts. A complete list of vaccines with their mercury/thimerosal content can be obtained from the FDA website.
All parents have to make a decision whether or not to immunize their children based on their own religious, moral and ethical beliefs. In Texas, parents do have the right not to immunize their children. However, state and local authorities also have the right to refuse admission to these children into school or other public institutions in the event that the child poses a health threat to others or the outbreak of a contagious disease poses a threat to that child. While the “to immunize or not to immunize” debate exceeds the scope of this article, let’s simply ask the question, what happens when children are not immunized?
Infant immunization is a relatively new practice. As new vaccines are developed, they are made available. However, American children have only been receiving vaccines for immunization on a specified schedule since the 1970s. It all started with the smallpox vaccine.
Smallpox (or Variola) has a long history of devastating societies and has been noted in the artifacts of many ancient civilizations such as the age of Egyptian pharaohs and ancient Asian cultures. Smallpox entered European cultures sometime between the 5th and 7th centuries and was often an epidemic killing thousands per outbreak. As world discovery spread, so did smallpox. Arab expansion, crusades by Spanish conquistadores, European “discovery” of the Americas and the slave trade (many areas of Africa were endemic with smallpox) all brought with them the spread of smallpox.
Smallpox affected all levels of society. For those who survived the disease (the fatality rate was anywhere from 20% to 60% and as high as 80% in infants) they were left with disfiguring scars and often blindness. But an interesting finding was that those who survived smallpox were subsequently immune from getting the disease again. This knowledge led to the practice of inoculation – pricking the pox of infected individuals and then injecting the pox fluid just under the skin of non-immune individuals. While inoculation was widely practiced in Africa, India and China for hundreds of years, it did not gain popularity in Europe until the mid-18th century.
Edward Jenner, a physician and scientist in mid-18th-century England, is credited with being the pioneer of modern day immunization. Jenner noted in his research that milkmaids who had contracted cowpox were also immune to smallpox. Having been inoculated with smallpox himself as a lad, Jenner wanted to see if using fluid from a less lethal infection could be effective in preventing smallpox. Using inoculation techniques, he tested his theory on a young boy. Pricking a pox of a milkmaid infected with cowpox, Jenner deposited the fluid under the skin of the young boy. The boy developed fever and lymph gland enlargement, but just over a week later, he was well. When Jenner subsequently inoculated him with smallpox, the boy did not become ill at all. Jenner had discovered the first vaccine (Vaccina meaning “from a cow”).
Although he reported his findings to many of the medical and scientific societies in England at the time, Jenner’s discovery only received limited acceptance. Jenner was not the first to make the association between vaccination and immunization but he was the first to pursue the concept with dogged research and to press medical societies that this was a way to prevent the spread of disease. While many “royal” physicians and scientists dismissed Jenner’s findings, many “country” physicians did take heed and soon inoculation against smallpox was practiced widely throughout Europe and The Colonies (America).
Routine vaccination of American children against smallpox continued until 1971 when smallpox was considered eradicated in the United States and production of the vaccine ceased. The World Health Organization declared smallpox eradicated worldwide in 1980. Production of the vaccine was restarted following the September 11, 2001 attacks on the World Trade Center and the vaccine is being stockpiled in federal warehouses in case of a bioterrorism attack.
The field of immunization really gained momentum in 1955 when Dr. Jonas Salk’s inactivated polio vaccine was licensed in the United States. Since then, vaccines against most of the major childhood illnesses have been developed and administered to children worldwide. Admittedly for some, it is hard to rationalize giving injections of these potentially lethal diseases to healthy children. But as a generation, we don’t know what it’s like to see children with leg length discrepancies and leg braces struggling to walk as a result of polio, deafness due to mumps, disfiguring scars due to pox or, thank heaven, to lose a child as a result of any one of these diseases.
But don’t take anyone’s word for anything when it comes to your children. Learn as much as you can about the vaccines that are required for immunization, learn about the diseases that they protect against and learn when they are most likely to occur and be most lethal. The following table provides a brief outline of the major illnesses and their vaccines for parents and caregivers.
More Info:
The U.S. Centers for Disease Control and Prevention – www.cdc.gov
The Advisory Committee on Immunization Practices – This committee advises the CDC on immunization practices and disease prevention www.cdc.gov/vaccines/recs/acip/default.htm
The American Academy of Pediatrics – www.aap.org
The American Academy of Family Physicians – www.aafp.org
The Effects Of Immunization
(A compilation of data from the U.S. Centers for Disease Control and Prevention, Medline and The Journal of the American Medical Association)
Polio
Polio or poliomyelitis is an extremely contagious viral infection. The disease spreads due to poor hygiene habits, primarily when individuals ingest food stuffs contaminated with the virus (which resides in stools).
Effect of Immunization
Prior to immunization, 13,000 to 20,000 cases of paralytic polio were reported each year in the United States.These annual epidemics affected children the most and left many crippled. The number of cases reported globally has decreased from more than 350,000 cases in 125 countries in 1988 to 2,000 cases of polio in 17 countries in 2006.
Current Standings
In 1988, the World Health Assembly agreed to eradicate polio worldwide. Six countries (Afghanistan, Egypt, India, Niger, Nigeria and Pakistan) still have circulating polio. Stopping immunization would lead to a resurgence of polio worldwide.
Diphtheria
Diphtheria is a disease caused by Corynebacterium diphtheriae, which produces a poisonous toxin that causes inflammation of the heart muscle, nerves and lung tissues. The fatality rate is 5% to 10%, with higher fatality rates (up to 20%) in young and elderly people.
Prior to Immunization
In 1921, 206,000 cases and 15,520 deaths were reported totally.
Effects of Immunization
With vaccine development in 1923, new cases of diphtheria began to fall in the U.S., until 2001, when only two cases were reported.
Current Standings
Approximately 0.001 cases per 100,000 in the U.S. since 1980. In the period of 1990-1999, more than 150,000 cases and 5,000 deaths were reported.
Tetanus
Tetanus is a severe, often fatal disease and the tetanus bacteria are found in soil and street dust, in the waste of many animals, and are very resistant to heat and germ-killing cleaners. People who get tetanus suffer from stiffness and spasms of the muscles causing breathing and eating difficulties, fractures of the spine and long bones and some people go into a coma and die. Approximately 20% of reported cases end in death. Tetanus in the U.S. is primarily a disease of adults, but unvaccinated children and infants of unvaccinated mothers are at risk. Tetanus annually kills 300,000 newborns and 30,000 birth mothers who are not properly vaccinated.
Prior to Immunization, from 1922-1926, there were around 1,314 cases of tetanus per year in the United States.
Effects of Immunization
In the late 1940s, the tetanus vaccine was introduced. As a result, cases of tetanus dramatically decreased. In 2000, only 41 cases of tetanus were reported in the U.S.
Current Standings
There has been an increase in tetanus cases among younger people in the U.S., notably among intravenous heroin users. Tetanus can only be prevented by immunization. If vaccination against tetanus were stopped, persons of all ages in the U.S. would again be susceptible to this disease.
Pertussis (Whooping Cough)
Pertussis is an illness that primarily affects children resulting in prolonged coughing spells lasting weeks. These spells make it difficult for children to eat, drink and breathe. Since vomiting often occurs after a coughing spell, infants may lose weight and become dehydrated. Affected infants who are 6 months old or younger will experience the highest rate of hospitalization, pneumonia, seizures, encephalopathy and death.
Prior to Immunization
Before the pertussis vaccine, nearly all children developed whooping cough. There were 150,000 to 260,000 cases reported each year, with up to 9,000 pertussis-related deaths.
Effects of Immunization
From 1990 to 1996, 57 persons died from pertussis; 49 of these were less than 6 months old.
Current Standings
A recent study found that in eight countries where immunization coverage was reduced, incidence rates of Pertussis surged to 10-to-100 times the rates in countries where vaccination rates were sustained.
Haemophilus Influenzae Type b (Hib) Meningitis
Hib was the most common cause of bacterial meningitis in U.S. infants and children. About one of every 200 U.S. children under 5 years of age developed invasive Hib disease. Approximately two-thirds of the 20,000 cases were Meningitis and one-third were other life-threatening invasive Hib diseases such as bacteria in the blood, pneumonia or inflammation of the epiglottis. Hib meningitis once killed 600 children each year and left many survivors with deafness, seizures or mental retardation.
Prior to Immunization
Before the vaccine, there were around 20,000 invasive Hib cases annually.
Effects of Immunization
Since introduction of a conjugate Hib vaccine in 1987, the incidence of Hib has declined by 98%. From 1994-1998 fewer than 10 fatal cases of invasive Hib disease were reported each year.
Current Standings
Today most pediatricians finishing training have never seen a case of Hib.
Measles
Measles is one of the most infectious diseases in the world and is frequently imported into the U.S. via international visitors or U.S. residents who were exposed to the measles virus while traveling abroad. More than 90% of people who are not immune will get measles if they are exposed to the virus. In the U.S., up to 20% of persons with measles are hospitalized. Complications include ear infections, pneumonia or diarrhea. Some persons with measles develop encephalitis, resulting in brain damage. While an average of three of every 1,000 persons with measles will die in the U.S.; in the developing world, about one out of every 100 persons with measles will die.
Prior to Immunization
Before the vaccine, nearly everyone in the U.S. got measles. On average, 450 measles associated deaths were reported annually between 1953 and 1963.
Effect of Immunization
In the U.S., widespread use of measles vaccines has led to a greater than 99% reduction in measles compared with the pre-vaccine era. If vaccinations were stopped, each year, about 2.7 million measles deaths worldwide could be expected.
Mumps
Mumps is usually a mild viral disease but in rare cases causes swelling of the brain, nerves and spinal cord, which can lead to side effects such as paralysis, seizures and fluid in the brain. Swelling of the testes (and impaired fertility) is the most common side effect in males past the age of puberty.. An increase in miscarriages has been found among women who develop mumps during the first trimester of pregnancy. Mumps is highly communicable and it only takes a few unvaccinated to initiate transmission.
Prior to Immunization
Mumps was a major cause of deafness in children, occurring in approximately 1 in 20,000 reported cases.
Effect of Immunization
The vaccine was licensed in 1967. Since 1989 and the two-dose schedule for measles, mumps, rubella or MMR, incidence has declined, with 266 reported cases in 2001.
Rubella
Up to 90% of infants born to mothers infected with rubella during the first trimester of pregnancy will develop congenital rubella syndrome (CRS), resulting in heart defects, cataracts, mental retardation and deafness.
Prior to Immunization
Before rubella immunization in the U.S., an estimated 20,000 infants were born with CRS, and there were 2,100 neonatal deaths and 11,250 miscarriages. Of the 20,000 infants born with CRS, 11,600 were deaf, 3,580 were blind and 1,800 were mentally retarded.
Effects of Immunization
Only six CRS cases were provisionally reported in the U.S. in 2000.
Current Standings
Because many developing countries do not include rubella in the childhood immunization schedule, foreign-born adults are currently those afflicted in the U.S. Since 1996, greater than 50% of the reported rubella cases have been among adults. Since 1999, there have been 40 pregnant women infected with rubella.
Varicella (Chickenpox)
Chickenpox is usually mild but can be severe in some persons. Serious complications include secondary bacterial infections, dehydration, pneumonia, and central nervous system involvement.
Prior to Immunization
Prior to vaccine licensing in 1995, almost all persons in the United States had suffered from chickenpox by adulthood. Each year, the virus caused around 4 million cases of chickenpox, 11,000 hospitalizations, and 100-150 deaths.
Effects of Immunization
In some areas, cases have decreased as much as 90% over pre-vaccination numbers. In 2006, a routine two-dose vaccination was recommended for anyone who did not have evidence of immunity to the disease. This strategy also decreased the risk of exposure to the virus for persons who are unable to be vaccinated because of illness or other conditions and who may develop severe disease. Without vaccination, everyone would eventually get chicken pox.
Hepatitis A
Hepatitis A is a highly contagious liver disease that results from infection with the Hepatitis A virus. The illness can be mild to severe and last a few weeks to a several months. Hepatitis A is usually spread via the “fecal-oral route” resulting from contact with an infected person or when contaminated food is ingested.
Prior to Immunization
An average of 26,000 Hepatitis A cases were reported annually during the 1980s and 1990s – an estimated 270,000 infections per year. More than half of these occurred among children.
Effects of Immunization
Before vaccination started in 1995, rates of Hepatitis A dropped 76% from the mid 1990s until 2003. Declines were greater among children aged 2-to-18 years (87%) than among persons older than age 18 years (69%).
Hepatitis B
More than 2 billion persons worldwide have been infected with the Hepatitis B virus at some time in their lives. Of these, 350 million are lifelong carriers of the disease and can transmit the virus to others. One million of these people die each year from liver disease and liver cancer. About 12.5 million Americans have been infected with Hepatitis B virus at some point in their lifetime. One and one quarter million Americans are estimated to have chronic infection, of whom 20% to 30% acquired their infection in childhood.
Chronic Hepatitis B virus infection increases a person’s risk for chronic liver disease, cirrhosis and liver cancer. Infants and children who become infected with Hepatitis B virus are at highest risk of developing lifelong infection, which often leads to death from liver disease (cirrhosis) and liver cancer. Approximately 25% of children who become infected with Hepatitis B virus would be expected to die of related liver disease as adults. One-third of the lifelong Hepatitis B infections in the United States resulted from infections occurring in infants and young children. About 5,000 persons will die each year from Hepatitis B related liver disease. About 16,000 - 20,000 Hepatitis B antigen infected women give birth each year in the United States.
Prior to Immunization
It is estimated that 12,000 children born to Hepatitis B virus infected mothers were infected each year before infant immunization. In addition, approximately 33,000 children (10 years of age and younger) of mothers who are not infected with Hepatitis B virus were infected each year before routine recommendation of childhood Hepatitis B vaccination.
Effects of immunization
The number of new infections per year has declined from an average of 450,000 in the 1980s to about 80,000 in 1999. The greatest decline has occurred among children and adolescents who are now routinely vaccinated.
Pneumococcal
Pneumococcal meningitis is an infection of the membranes covering the brain and spinal cord caused by Streptococcus pneumoniae, the most common cause of meningitis in adults, and the second most common cause of meningitis in children older than age 6. The onset of symptoms is usually rapid and includes high fever, severe headache, nausea and vomiting, light sensitivity, stiff neck and mental status changes. Twenty percent of people who contract this disease will die of it and 50% will have serious long-term complications such as deafness, paralysis, mental retardation and fluid accumulation in the brain.
Prior to Immunization
Before vaccination started in 2000, pneumococcus caused 63,000 cases and 6,100 deaths in the U.S. each year. Many children who developed pneumococcal meningitis also developed long-term complications such as deafness or seizures.
Effect of Immunization
Since vaccination, the incidence in children has been reduced by 75%. The vaccine also reduces spread from children to adults. In 2003, there were 30,000 fewer cases caused by strains included in the vaccine, including 20,000 fewer cases in children and adults too old to receive the vaccine.
Current Standings
Incidence rates dropped 64% in children under age 2 in the years 1998-1999 to 2004-2005. There has been a 54% decrease in cases amongst those older than 65 years. Overall, there has been a 73.3% decrease in cases of those strains covered by the vaccine. Unfortunately, there has been a 60.5% increase in cases of strains not covered by the vaccine.