|Medical Matters in
Recommended Vaccinations, Immunizations,
Inoculations and Prophylaxis for Travel to Nepal: Updated July 1999.
Every decision to take a vaccine to prevent an illness is essentially
a decision that the short term expense and slight discomfort (and slight risk)
is worth the improved chance of avoiding an unpleasant or potentially fatal illness.
The following recommendations are based on the advice of international agencies
such as the World Health Organization and the Centers for Disease Control in the
United States, coupled with our local experience. Vaccine recommendations occasionally
vary from Europe to North America, usually in regard to the exact schedule of
giving the vaccine. The results of vaccination can be the same with different
The protection that
can be gained from vaccines varies from 50% to almost 100%. So remember that even
if you have taken a vaccine you might still get the disease, although you will
have greatly reduced your chances of getting ill.
the Prevention of Hepatitis A:
A is a virus that infects the liver, causing a disease known as viral hepatitis.
The disease is distinctly unpleasant, with profound nausea, loss of appetite,
and weakness that can last for weeks. It can also be fatal on rare occasions.
Fortunately this disease can be prevented by immunization or by gamma globulin
injection. If you have had hepatitis A in the past, you will be immune for life
and do not need the vaccine. The virus is passed in human feces (shit), and is
acquired the same way that you acquire traveler's diarrhea. Therefore, it is very
difficult to avoid through safe eating habits.
A Vaccine: Many brands have entered the market now and the most popular ones
are "Havrix" and "Vaqta". Other names include "Avaxim"
and "Twinrix" which is a combined Hepatitis A and B vaccine. All of
these vaccines are equally safe, effective, interchangeable (except for Twinrix)
and offer long lasting protection against Hepatitis A, making gamma globulin injections
no longer necessary for people who take the hepatitis A vaccine. Since hepatitis
A virus is spread through fecal contamination, travelers and residents in Nepal
are at constant risk if they do not take either gamma globulin or the Hepatitis
A vaccine. Most of these vaccines are given as a series of 2 injections except
for Twinrix, the combined vaccine which is given as a series of 3. Havrix which
is what we stock at CIWEC Clinic, is given as a series of 2 injections, 1440 international
units per injection of the vaccine is given on day 0, and then a booster is given
from 6-12 months later, with adequate protection about 2 weeks after the first
Gamma Globulin: This
is being used less and less as most travelers and almost all expatriates are getting
immunized with the Hepatitis A vaccine. This is not a vaccine, but a collection
of antibodies purified from the blood of an immune population. This was the original
and highly effective method of preventing Hepatitis A. However, short term travelers
who may not ever travel again may choose the less expensive gamma globulin over
the vaccine. Gamma globulin, although derived from human blood, has repeatedly
been shown to represent no risk of transmitting the HIV virus which causes AIDS.
We recommend taking one milliliter of gamma globulin for each month of intended
travel, plus an extra milliliter, to a maximum of five milliliters for four months
protection. After four months, the protection of gamma globulin begins to wear
off, and a repeat injection is required.
the Prevention of Hepatitis B:
B Vaccine: This is a well established vaccine with high safety and efficacy.
Hepatitis B is spread through direct contact with infected blood, and travelers
to Nepal have very little chance of acquiring this infection through normal travel.
If you don't have unprotected sex, or have injections under questionable circumstances,
you probably cannot acquire this disease. However, since there is a small chance
of infection through the above methods, and the disease can become chronic or
fatal, many long term travelers and foreign residents decide to take this series
of injections. In addition, since there are no animal reservoirs of infection,
an effort is being made to give hepatitis B vaccine to all humans, which would
eventually eliminate the disease from the world, much as smallpox was eliminated
by a vaccination campaign in the 1970's. The regimen for hepatitis B vaccine is
an initial injection followed by boosters at one month and six months.
the Prevention of Typhoid Fever:
fever is a prolonged febrile illness caused by infection with Salmonella typhi
bacteria. An almost identical illness, called paratyphoid fever, is produced by
Salmonella paratyphi. Infection with either organism is referred to as enteric
fever. The organisms are passed in human feces (shit), and acquired by eating
contaminated food or water. The disease is rarely fatal in foreigners, and can
be treated with antibiotics. However, it makes you very sick and complete recovery
can take several weeks. Therefore, we recommend taking a vaccine to prevent typhoid
fever, which is an extremely common illness in Nepal (about 1 in 300 unvaccinated
travelers get the disease). There are currently three different typhoid vaccines
on the market: A whole cell killed typhoid vaccine, an oral typhoid vaccine using
live organisms, and a capsular polysaccharide injectable typhoid vaccine. At CIWEC
Clinic, we are currently only stocking the capsular polysaccharide vaccine.
Polysaccharide Typhoid Vaccine (Typhim Vi): This vaccine
consists of a highly purified coating of the Salmonella typhi bacteria. Because
the whole bacteria is not injected, side-effects are minimal. It consists of a
single injection of the vaccine with protective efficacy around 80%, with boosters
required every two years. There is no cross-protection against Salmonella paratyphi
but it offers good protection against typhoid fever. This vaccine is gaining in
popularity since it is a single injection and is relatively free from side effects.
Whole Cell Killed Typhoid Vaccine:
This was the original typhoid vaccine, invented almost 100 years ago. Salmonella
typhi bacteria are grown and then killed with either heat or chemicals, and
then injected. Studies in local populations show an efficacy of 50-94%, with an
average of 65%. Among tourists who are trying hard to avoid diarrhea (and thus
avoiding eating contaminated food or water) the efficacy may be higher. In studies
that we performed at the CIWEC Clinic, the injectable vaccine was 95% protective
against S typhi, and 75% protective against S paratyphi A. It does
not appear that the oral or capsular polysaccharide vaccines offer any cross-protection
against S paratyphi A. Thus, the original whole cell injectable vaccine
may have some advantages in Nepal, where S paratyphi A infection accounts for
about 35% of the cases of enteric fever. The whole cell injectable vaccine causes
some local discomfort and occasionally fever for one day. The orginal course of
vaccine consists of two injections, one month apart. Boosters are required every
three years to maintain immunity.
Typhoid Vaccine: This vaccine consists of a live strain of Salmonella typhi
that has been altered so that it can cause immunity, but not cause typhoid fever.
The bacteria are enclosed in coated capsules that dissolve when they get in the
intestines, releasing the live organisms, which grow for a while and then die.
The capsules are taken every other day for a total of three or four doses (the
U.S.A. recommends four doses, while the rest of the world uses three). Protection
is between 50-65%. There are virtually no side effects. It is a bit of trouble
to keep the capsules refrigerated between doses, and to remember to take them
for a week. Also, you cannot be taking any antibiotics at the time. This vaccine
offers no cross-protection against Salmonella paratyphi. The vaccine is
of value for people who have had a bad reaction to the old injectable typhoid
vaccine in the past, or who simply wish to avoid another injection.
the Prevention of Meningococcal Meningitis:
Meningitis: Centers for Disease Control (CDC) in the U.S. has stopped recommending
this vaccine since 1998 for travel to Nepal, but we continue to offer it as this
is a very safe vaccine with efficacy lasting 3-5 yrs. Meningococcal meningitis
is a severe bacterial infection of the lining of the brain which is usually rapidly
fatal without treatment. There was an epidemic of meningococcal meningitis in
the Kathmandu valley in 1983. In 1984, a widespread vaccination program prevented
a second epidemic. 6 cases of meningococcal meningitis occurred in foreigners
then, mostly in trekkers that led to the CDC to issue a travel advisory recommending
the meningococcal meningitis vaccine for all travelers to Nepal. Meningitis is
spread through coughing or sneezing in a closed environment, with the bacteria
entering your body through the nose and mouth. Although the risk of acquiring
meningitis is low, the outcome can be rapidly fatal (you can die in one day).
The vaccine is safe, 90% effective, and the protection from a single shot lasts
three to five years in people over age five, and two years in children under five.
For the Prevention of Japanese
B Encephalitis (JE) Vaccine: JE is caused by a virus carried
by culex mosquitoes in rural areas of southern Nepal or the Terai. This virus
can cause a severe and often fatal infection of the brain. Previously it was assumed
that this disease did not exist in the Kathmandu valley but in 1998, doctors at
Patan Hospital found JE in persons who had not left Kathmandu for 6 months before
getting ill. It is difficult to calculate the risk in foreigners since there has
not been a single case of JE in a foreigner in Nepal. The actual risk probably
is extremely low. Short term visitors to Nepal who will spend a week or two in
Kathmandu, Pokhara or the trekking routes are the lowest risk individuals who
most likely do not need the vaccine. Longer term visitors to Nepal particularly
the ones visiting in the post-monsoon months of August-October and resident expatriates
may wish to consider immunization against JE. We continue to strongly recommend
the vaccine for foreign workers living in the Terai. Casual visitors to the Terai
probably do not need the vaccine. The full series, for prospective residents of
an endemic area, is 3 shots given on days 0, 7, and 28. If time is short, the
3 shots can be given one week apart. One should have a booster every 3 years if
For the Prevention
of Rabies Encephalitis:
Vaccine: Rabies virus is transmitted by the bite/scratch of infected animals
or from saliva contact with mucous membranes. The disease is present throughout
Nepal, India, and Tibet. Most of the disease in humans is from the bite of an
infected dog. The rabies virus, once injected by a bite, travels slowly to the
brain over a period of weeks to years, causing a fatal encephalitis. Because of
the delay between the bite and clinical illness, rabies vaccine and immunoglobulin
can be injected after a bite to prevent the person from developing a rabies infection.
This post-exposure series offers essentially 100% protection, with minimal
side-effects. However, it takes a month to complete the five shots plus the initial
injection of human rabies immune globulin (HRIG), which is a very expensive substance
($600 to $1000 depending on your body weight). For this reason, long-term travelers
or foreign residents often take a pre-exposure series, consisting of 3
shots on days 0, 7, and 28, followed by a booster in a year. People who have completed
the first 3 shots are considered pre-immunized against rabies, and if they are
subsequently bitten by an animal, they require only two more boosters, 3 days
apart. They avoid the expense of the HRIG, and the nuisance of having to get 5
shots over a one month period. The risk of being bitten by an animal in our recent
study was 3 out of 1000 persons for one year of travel with double the risk if
one is an expatriate resident living mainly in Kathmandu. Trekking was not associated
with increased risk of exposure. The decision as to whether to take a pre-exposure
series is up to the individual since effective post-exposure therapy exists. However,
we highly recommend the pre-exposure series for children, who may not report to
their parents every contact with a stray animal or someone's pet. After the one
year booster, one should get a booster every 3 years. The CIWEC Clinic always
has supplies of HRIG, but this expensive substance is not available in Tibet or
most parts of India.
the Prevention of Tetanus:
Vaccine: Tetanus bacteria can infect small wounds and cause a fatal infection.
The risk is the same throughout the world. For this reason, most people have received
tetanus vaccine (usually mixed with diphtheria vaccine for greater effect), since
early childhood. Boosters should be obtained every 10 years, and foreign travel
is an opportunity to review one's tetanus vaccine status.
the Prevention of Polio:
Vaccine: Polio virus used to be endemic in Nepal and mass vaccinations of
children against Polio have been undertaken by WHO since 1997 which may eventually
help eradicate this disease. Almost all tourist and foreign residents have been
vaccinated against this disease in childhood. However, this initial immunity can
decrease over the years, and one booster as an adult is recommended if
you travel to developing countries. The booster can be oral or injectable if you
have previously been immunized. If you have never been immunized against polio,
you need to get the injectable inactivated vaccine.
the Prevention of Cholera:
Vaccine: The risk of cholera to the foreign traveler or resident in Nepal
is close to zero. Cholera is mainly spread by heavily contaminated water, or by
certain sea coast animals that concentrate the bacteria (such as oysters). If
you are conscientious in not drinking untreated water (or milk, which is often
contaminated with water), you will have almost no chance of getting cholera. The
new oral cholera vaccine is now available, which is reasonably effective with
few side-effects. However, the risk of cholera for the average traveler is so
low, that routine cholera immunization is still not recommended. The CIWEC Clinic
does not stock cholera vaccine.
the Prevention of The Flu.
Vaccine: Influenza, or the flu, is a viral illness that causes
fever, muscle aches, cough, and misery for a number of days. The attack rate is
high among travelers, who often are more vulnerable due to the stress of travel,
and the congestion of many forms of public transport and restaurants. The vaccine
consists of killed particles of three different strains of influenza, and can
cut your risk of getting sick with the flu by about 50%. Although not routinely
recommended to travelers, it is a safe vaccine that may save you a week of discomfort
on your holiday, or prevent your being ill during a brief working trip to Nepal
or India. A single injection offers protection for about one year. New vaccines
are formulated each year based on world-wide reporting of which flu is going around.
The new vaccines are released in the fall and CIWEC Clinic will make this vaccine
available each year. We participate in the annual flu surveillance, a world-wide
monitoring of flu strains and our data should help in making a new vaccine for
the Southern hemisphere.
Information from the
world famous Travel Medical Center CIWEC Clinic of
Kathmandu. See their sight for more information on
AMS (Altitude Sickness) and Travelers Diarrhea. Just