Can measles be prevented? There is a clear unequivocal answer to this question and it is yes.
Measles infection is best prevented by vaccination. Due to the highly contagious nature of measles
it is critical to maintain high levels of population immunity by vaccination
to control and ultimately eradicate this viral infection. Approximately 94 to 95 percent
immunization coverage is required to maintain herd immunity, meaning broad population immunity, and to
interrupt continued transmission of measles. What is the history of development of measles vaccines?
The first measles vaccine which was created by inactivating, that is killing, the virus
was developed and licensed in the united states in 1963. The current vaccine is live attenuated,
meaning a weakened vaccine, so they it's live virus, but the virus has been weakened in the laboratory.
This was introduced in 1968. Measles vaccines used in the United States now are combined with
mumps and rubella, and the vaccine is called MMR (measles, mumps, and rubella) or combined with mumps,
rubella and varicella. Varicella is chicken Pox and that's the MMRV vaccine (measles, mumps, rubella,
and varicella). For many years only a single dose of measles vaccine was given to young children, but
because of occasional infections still occurring, a two-dose strategy was adopted in the United States
in 1989. And now the standard vaccination schedule for measles prevention and control
is the administration of two doses the first dose of vaccine is given between 12
and 15 months of age, and the second dose is given between 4 and six years of age.
What are the side effects of measles vaccines? Well as is true of all vaccines that are injected
into the body, there may be some local discomfort from the needle, so a little bit of pain, sometimes
a little bit of swelling or redness that lasts typically a day or two days. The available measles
vaccine are very safe in immunocompetent people people with a normal immune system. The adverse
reactions to the vaccines often may include fever, usually about 10 to 15 percent of recipients, there
may be a transient that is a temporary rash that occurs in about five percent of vaccine recipients,
and these symptoms the fever and the rash usually occur about a week to two after the vaccination
has been given, and they persist for one or two days. The reason they occur one to two weeks after
the vaccination is remember the vaccine is a live but weakened form of the virus so the vaccination
may imitate, but at a very reduced level, some of the symptoms associated with measles itself.
Brain inflammation, or encephalitis, after a measles vaccine is very rare. It is estimated to occur
less than one time in one million recipients of a measles vaccine. Other serious adverse events also
are unusual, these include febrile seizures, that is seizures occurring when the child's temperature
rises. This is estimated to occur about one time in every 3,000 recipients of the vaccine. Low platelet
count may occur. This is estimated to be at about one case for 30,000 doses of measles vaccination.
And rarely anaphylaxis which is that which you can get after a bee sting you know with a rash,
some swelling, maybe some difficulty breathing, it's called an anaphylactic reaction,
that occurs somewhere between 2 and 14 times for every million doses of vaccine given.
Allergic reactions related to allergies to egg or egg products, or to the neomycin,
a small amount of which is in the vaccine, are very uncommon. In fact patients with a history
of non-anaphylactic egg allergies, or contact dermatitis, a rash on the skin from neomycin
can safely receive measles vaccination. There are hypothesized associations-, or, there have been
hypothesized associations, between measles vaccine and the development of inflammatory
bowel diseases like crohn's disease or autism. These associations have not been supported by many
rigorously conducted and analyzed studies in the United States and around the world.
Questions covered in the next video: How effective are the measles vaccines?
Why have measles cases been increasing recently in the United States? And finally,
What are the current requirements for measles vaccination in the United States?