I would like to discuss a very important and often misunderstood topic
this month, vaccines. There is a lot of misinformation on the Internet,
TV, and in various books. Vaccines are of vital importance to the overall
health of a person and the population along with disease prevention. Vaccines
have been used in the prevention of diseases for many years. Throughout
history there have been many instances of large smallpox epidemics. During
the 1700’s, the primary method of prevention was the concept of
variolation, which involved placing dried scab material from those infected
with smallpox on young children not yet infected. (The term variolation
comes from the scientific name for smallpox, Variola.) This method would
hopefully result in a mild infection in which the child would recover
in two to four weeks as well as an acquired immunity to smallpox. Edward
Jenner, who was a country doctor, noticed that the milkmaids who had been
infected with cowpox on their hands did not become infected with smallpox
after exposure.
In 1796 in England, using this idea as a theory, he took pus from a cowpox
lesion on a milkmaid and introduced it into an eight year old boy’s
arm. Six weeks later, he then took smallpox and did the same thing in
two spots on the boy’s arm. The boy did not develop smallpox from
this or subsequent exposures. This was the first use of a vaccine. In
the late 1870’s, Louis Pasteur was studying fowl cholera, a highly
contagious disease found in chickens and other fowl. Part of his studies
included infecting chickens every few days with the live bacteria. However,
at one point he took a vacation and let some of the cultures sit out.
Upon his return, after injecting the chickens, he noticed they did not get sick.
He then infected them with a culture that had not been sitting out for
a long period, and they still did not become sick from the disease. Pasteur
realized this technique could work for other diseases as well. He then
decided to study rabies and developed the first live virus vaccine in
1884. The work of Jenner and Pasteur paved the way for the bacterial and
viral vaccines we use so often today to be developed.
There are currently four different types of vaccines: live virus, killed
(inactivated) virus, toxoid, and biosynthetic. Live virus vaccines are
made from a weakened (attenuated) form of the virus. These include chickenpox,
measles, mumps, rubella, and the nasal flu vaccine. Killed vaccines are
made from pieces of a virus or bacteria. The injected flu vaccine is an
example of a killed vaccine. Toxoid vaccines contain a chemical or toxin
made by the bacteria or virus. These include diphtheria and pertussis.
Biosynthetic vaccines contain man-made substances that are similar to
the virus or bacteria. An example of a biosynthetic vaccine is for Haemophilus
influenza type B, which is a major cause of spinal meningitis. All vaccines
work by teaching your body how to defend itself when exposed to a spe-cific
germ. Your body uses whatever material is delivered via the vaccine to
create protein molecules called antibodies. Eventually these antibodies
do die. However, upon later ex-posures to the same bacteria or virus,
the immune system through memory cells cre-ates the same antibodies as
before to fight the infection. We need vaccines to protect us because as
babies we have a small amount of immunity that has been passed from our
mother, but this immunity soon goes away. Vaccines protect us from diseases
that used to be very common, such as measles, mumps, rubella, whooping
cough, meningitis, and polio. These diseases can cause serious and even
life-threatening illnesses. Vaccines also work by providing “herd
immunity” meaning that everyone who has received the vaccine is
immune to that specific disease keeping the disease from being carried
or spread. This herd immunity helps to protect those that are too young
to receive vaccines or those who have immune systems that are too weak
to handle the disease.
In the United States, we have multiple vaccines. Some of which are required
to attend school and others which are recommended but optional. Required
vaccines for babies and children are the following: measles, mumps, rubella
(MMR); diphtheria, tetanus, pertussis (DTap); Polio; Rotavirus; Pneumococcal,
Meningococcal, Haemophilus influenzae type B (Hib); Hepatitis B; Hepatitis
A; and Varicella (chicken pox). The optional vaccines are the flu vaccine
and the human papilloma virus (HPV) vaccine. Recommended vaccines for
the older population are flu, pneumonia (both the pneumovax 23 –
the one that has been recommended to those over 65 for many years and
the Prevnar 13 – the one recommended for babies), and shingles.
Dr. Amanda Bailey, DO works at
Catawba Valley Family Medicine – Claremont at 2890 South Lookout Street in downtown Claremont. For more information
or to schedule an appointment with Dr. Bailey, call Catawba Valley Family
Medicine – Claremont at 459-7324, or visit
http://www.cvmgonline.org