From: "Mark A. Shelly"=20

>A typhoid vaccination is recommended for a trip to Costa Rica.  My family
>doctor said that the last time she gave someone a prescription for the
>vaccine they came back with an oral vaccine.  Since then she hasn't been
>able to find any information comparing the oral to the injectable form:
> - efficacy
> - scheduling (the injectable form requires 2 doses, the first a month
>   before the trip)
> - side effects (she says that the injectable form tends to make you feel
>   sick, the oral form may be an improvement).

Oral typhoid vaccine is a live but weakened (attenuated) strain (Ty21a) of
the Salmonella germ that causes typhoid fever.

The oral vaccine is probably equal to the injected vaccine in efficacy, at
about 80%.

It is given orally on an empty stomach every other day for 4 doses (total
elapsed time 6 days). It must be kept refrigerated but not frozen, a signif=
icant
limitation to use in other countries. You can't be taking antibiotics at th=
e
same time.

It is very well tolerated. (The injected form has 80+% side effects). If yo=
u
have weakened immunity, or if you are too young to take pills, you shouldn'=
t
use this vaccine.

I almost never recommend the injected form of typhoid vaccine. Typhoid
vaccine is recommended for travel to areas with poor water supplies when
the trip is over 3 weeks and when your eating will be "high risk".

Hope this helps

Mark Shelly
mshelly@medicine.rochester.edu
------------------------------------------------------------------------

Typhus vaccine (not available in the US) is described by Andreas Kaunzner's=
 travel medicine Web site
(http://members.aol.com/reisemed/impfung/typhus.htm). According to this sit=
e, there are two different typhus vaccines on the
market in Germany. One is a live oral vaccine, which is given in three dose=
s, and gives protection for about three years, if one
stays in a region where typhus is endemic; otherwise its immunity lasts for=
 about a year. The most common side effect, seen in
fewer than 1% of those receiving the vaccine, is stomach trouble. General s=
ymptoms such as fever and chills can appear, and
very seldom a rash. The other is a killed vaccine, which may be given to ad=
ults and children two years or older, and which
provides immunity for at least three years. Its side effects are described =
as "typical side effects of vaccinations" (local reactions,
fever, and allergic reactions) appearing only seldom. Kabel 1 Online has a =
chart of German travel vaccine recommendations
(http://www.kabel1.de/reise/1998/06/26/11/) which says that typhus vaccine =
is given for trips of more than three months. The
CDC, on the other hand, recommends hygiene and, in areas where tick typhus =
is endemic, tick removal and tick repellant;
typhus vaccine production has been discontinued in the US.=20

Yellow fever is a viral infection which is spread by mosquitos. Yellow feve=
r vaccine is a live vaccine which can be given only at
certain vaccination centers. Many countries require this vaccination for en=
try. A booster is needed every ten years.
Contraindications include egg allergy and immune deficiency. Reactions are =
mostly mild.=20

Vaccine components capable of causing adverse reactions: chick embryo compo=
nents (Travel Medicine Advisor).=20

Travelers may also want to take anti-malarial drugs, bring insect repellant=
 containing N,N diethylmethylbenzamide, and avoid
unboiled water, raw vegetables, fruit they haven't peeled themselves, under=
cooked fish and shellfish, and food kept at room
temperature. Other sources of travel health information are _Fielding's Tra=
velers' Medical Companion_ and the US State
Department Citizen's Emergency Center, which provides information on a vari=
ety of foreign travel risks 24 hours a day at
202-647-5225. CDC Travelers' Health Section, 404-332-4559, and Immunization=
 Alert, 203-487-0611, have up-to-date
information on vaccinations for international travel.=20

=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=
=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=
=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=
=3D=3D=3D=3D
Section 3n. Vaccines under development=20

[This section most recently updated on September 18, 1999. References inclu=
de the Report of the Technical Review Group
Meeting, 7-8 June 1998 WHO Global Program for Vaccines and Immunization Vac=
cine Research and Development
(http://www.who.org/gpv-documents/DocsPDF/www9845.pdf), a New England Journ=
al of Medicine editorial on malaria
vaccine development at http://www.nejm.org/content/1997/0336/0002/0128.asp,=
 reports on AIDS vaccine research at
http://www.iapac.org/ and http://www.nih.gov/news/pr/may98/od-15a.htm, an I=
ntellihealth report on vaccine news for 1999
(http://www.intelihealth.com/IH/ihtIH?t=3D18784&p=3D~br,IHW|~st,408|~r,WSIH=
W000|~b,*|), Lon Morgan's Web site on
vaccine developments: http://fp1.cyberhighway.net/~lmorgan/developments/vac=
cine_development.htm, and National Institute of
Health information on clinical trials at http://www.niaid.nih.gov/.]=20

Q3n.1 What vaccines are currently under development?=20

New vaccines under development include vaccines for HIV (vaccines are being=
 tested both to improve the immune response in
those already infected and to resist infection), respiratory syncytial viru=
s (Rathone), malaria, leprosy, gum disease, herpes,
shigella, dengue, cervical cancer, type I diabetes, and other illnesses, as=
 well as an intranasal flu vaccine, new versions of the
pneumococcal, meningococcal, and TB vaccines. Harrison's Internal Medicine =
has a list of vaccines in human trial, and a list of
those toward which priority efforts are being targetted.=20

As of May, 1998, the National Institutes of Health had evaluated 23 vaccine=
 candidates and 10 adjuvants (substances that
might enhance the effect of a vaccine) in 49 Phase I and Phase II clinical =
trials to determine the safety of the vaccine candidates
and their effect on the human immune system. These studies have been conduc=
ted with 2,900 volunteers. Despite all these
vaccine candidates, the variation of retroviruses and the virus transmissio=
n directly from cell to cell by fusion pose significant
obstacles. It's anyone's guess when (and if) an AIDS vaccine will be ready.=
 Two articles which discuss AIDS vaccine
development are "Vaccine Against AIDS?" in the British medical journal Lanc=
et ((02/26/94) Vol. 343, No. 8896, P. 493) and
"AIDS Vaccine: Shooting Blanks or Loaded for Bear?" in Men's Fitness ((03/9=
4) Vol. 10, No. 3, P. 118). Information about
efforts to produce an AIDS vaccine is sometimes posted in sci.med.aids, and=
 references, updates, and current information is
available by gophering to odie.niaid.nih.gov. If you have gopher, gopher od=
ie.niaid.nih.gov will get you there. The AIDS FAQ
(available from the pub/usenet/sci.med.aids directory of rtfm.mit.edu) desc=
ribes some other Internet resources with information
about AIDS.=20

When I wrote this section in 1994, I had, "The malaria vaccine has shown po=
sitive results in Phase I/II trials, which were
reported on February 18, 1994 issue in the British medical journal _Vaccine=
_ (volume 12 no. 4, pp 328-336; 1994). (A
report on an earlier trial can be found in the medical journal Lancet, volu=
me 341, pp 705-710; l993). More details can also be
found in a WHO press release kept on gopher.who.ch. The first results of Ph=
ase III trials are expected to be available in
October 1994." Unfortunately, the years since then have not seen as much pr=
ogress toward a malaria vaccine as was hoped. It
is known to be possible to induce immunity to malaria, as letting volunteer=
s be bit by irradiated mosquitos has done so. But
translating that into an effective vaccine has proved tricky. An editorial =
in The New England Journal of Medicine -- January 9,
1997 -- Vol. 336, No. 2 reported that, though one vaccine has shown efficac=
y, recent trials in malaria endemic areas couldn't
confirm that efficacy. An improved subunit vaccine reported in the same iss=
ue of NEJM, but needs to be tested in malaria
endemic areas. WHO has malaria vaccine as a high priority, and aims to have=
 an effective and affordable vaccine within the
next decade.=20

Respiratory syncytial virus (RSV) is a major respiratory pathogen among inf=
ants and young children which results in an
"estimated 90,000 hospitalizations among infants in the US every winter" (W=
illiams, 1997). Trials have indicated that the
vaccine is safe and immunogenic (produces antibodies), but there are mixed =
results so far on efficacy.=20

Shigella is one of the leading causes of diarrhoeal illnesses. A shigella v=
accine is moving toward clinical trials soon.=20

The vaccine for periodontitis (gum disease) has shown some positive results=
 in macaque monkeys (less bacterially induced
bone loss in the vaccinated monkeys), indicating that a human periodontitis=
 vaccine is feasiable. Full-fledged clinical trials,
however, may be a decade away.=20

Q3n.2 What other research is being done to improve vaccines?=20

Research is being done to improve existing vaccines (such as the research w=
hich resulted in the new acellular pertussis
vaccine). This includes efforts to decrease the number of visits, the numbe=
r of doses, and the number of injections, to move
immunization as early in life as possible (including research into the valu=
e of giving vaccines to pregnant women to provide
protection to infants very early in life), to decrease adverse effects, to =
increase protection, and to increase thermal stability. One
area being explored is whether it is possible to combine more vaccines in a=
 single shot. Micro-encapsulation is an attempt to
encase vaccines in microcapsules which will be released over time, mimickin=
g repeated injections. Trans-disease vaccinology is
an attempt, by genetic engineering, to create vaccines which protect agains=
t more than one disease. Efforts are also under way
to produce a heat-resistant polio vaccine. (Hartveldt) (There is also a Uni=
ted Press International article from 3/25/94, included
in the CDC AIDS Daily Summary for March 28, 1994, which discusses the effor=
t to make a vaccine which will be effective
against a variety of different viruses.)=20

A major vaccine safety problem is the widespread reuse of syringes in devel=
oping countries, due to scarcity, resale value, and
cultural resistance to waste. In response to this problem, monodose, dispos=
able vaccines, and solid, non-injected vaccines are
being looked at. Solid vaccines would also eliminate the cost of keeping va=
ccines cold (a major factor in vaccine delivery costs,
and reduce the cost of wasted vaccines. Other research on different vaccine=
 delivery methods includes work on an intranasal
flu vaccine and on an aerosol measles vaccine.=20

=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=
=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=
=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=
=3D=3D=3D=3D
Section 4. References=20

AAP recommendations (found at http://www.aap.org).=20

ACIP recommendations (found at http://www.cdc.gov/nip)=20

AMA Drug Evaluations Annual, 1993.=20

The American Medical Association Family Medical Guide. Random House, New Yo=
rk. 1987.=20

The American Hospital Formulary Service Drug Information, 1992. Published b=
y the American Society of Hospital
Pharmacists.=20

Boughton, Clement R. "Varicella-zoster vaccine." The Medical Journal of Aus=
tralia. Vol. 159. 4 October 1993.=20

California Morbidity, a Biweekly Report from the Division of Communicable D=
isease Control, part of the State of California
Health and Welfare Agency. Issues from October 31, 1987, May 21, 1993, and =
November 19, 1993.=20

Catalana, Paul, MD. "The 'Other' Childhood Immunizations." Emergency Medici=
ne, October 15, 1992. Center for Disease
Control. _Health Information for International Travel_, 1992.=20

Center for Disease Control Vaccine Information Statements (found at http://=
www.cdc.gov/nip).=20

Clements, C. John, Strassburg, Marc, Cutts, Felicity T. and Torel, Carol. "=
The epidemiology of measles." In _World Health
Statistics Quarterly, Vol 45, No 2/3, 1992.=20

FDA. "Advisory Committee Discusses Chickenpox Vaccine." January 28, 1994. (=
Pulled off of fdabbs.fda.gov. Connect with
login bbs to find this and other FDA information.)=20

Fettner, Ann Giuici. _The Science of Viruses._ Quill. William Morrow, New Y=
ork, 1990.=20

Galazka, Artur. "Control of Pertussis in the World." In _World Health Stati=
stics Quarterly_, Vol 45, No 2/3, 1992.=20

Gershon, Anna A. "Varicella - Immunization Practices in Children." Hospital=
 Practice. Sept. 15, 1990.=20

Ghendon, Y. "Influenza - its impact and control." In _World Health Statisti=
cs Quarterly, Vol 45, No 2/3, 1992.=20

Harrison's Principles of Internal Medicine, Eleventh Edition. McGraw Hill B=
ook Company, 1987.=20

Hartveldt, Frank. "The Children's Vaccine Initiative." World Health 46th ye=
ar, No. 2, March-April 1993.=20

Historical Statistics of the United States, Colonial Times to 1970. Bicente=
nnial Edition. US Department of Commerce, Bureau
of the Census.=20

Hull, Harry F. and Ward, Nicholas A. "Progress towards the global eradicati=
on of poliomyelitis." In _World Health Statistics
Quarterly, Vol 45, No 2/3, 1992.=20

Journal Watch, 9-1-93. "Infant HBV Vaccination: Doubts Remain."=20

Kiple, Kenneth E., Editor. _The Cambridge World History of Human Disease_.=
=20

The Lippincott Manual of Nursing Practice, Fourth Edition. 1986.=20

Mandell/Douglas/Bennett. Principles and Practice of Infectious Diseases, Th=
ird Edition, 1990.=20

The Medical Letter on Drugs and Therapeutics, Vol. 34 (Issue 875), July 24,=
 1992.=20

The Merck Manual, Sixteenth Edition. Merck Research Laboratories, 1992.=20

Nossal, Sir Gustav. "Prospects for new vaccines." World Health 46th year, N=
o. 2, March-April 1993.=20

Onorato, Ida M., MD, Wassilak, Steven G. Md, Meade, Bruce, PhD. "Efficacy o=
f Whole-Cell Pertussis vaccine in Preschool
Children in the United States." JAMA, May 27, 1992, Vol. 267, No. 20.=20

Pantell, Robert H., MD, Fries, James F., MD, and Vickery, Donald M., MD. _T=
aking Care of Your Child: A Parents' Guide
to Medical Care._ Third Edition.=20

The Physician's Desk Reference, 1993.=20

Rathone, Mobeen H., MD. "Childhood Immunizations: An Update." Infections in=
 Medicine, June 1992.=20

Ryan, Frank, M.D. _The Forgotten Plague: How the Battle Against Tuberculosi=
s Was Won - And Lost_. Little, Brown, and
Company, 1993.=20

Shapiro, Eugene D., MD "Editorial: Pertussis Vaccines: Seeking a Better Mou=
setrap." JAMA, May 27, 1992, Vol. 267, No.
20.=20

Smith, Alice Lorraine. Principles of Microbiology. The C. V. Mosby company.=
 St. Louis, Toronto, and London, 1992.=20

Statistical Abstracts of the United States, 1992.=20

Travel Medicine Advisor. May 1993.=20

Trollfors, B. and others. "A Placebo-Controlled Trial of a Pertussis-Toxoid=
 Vaccine." NEJM, Vol 333, Number 16, October
19, 1995.=20

University of California, Berkeley. _The Wellness Encyclopedia._ From the e=
ditors of the UC Berkeley Wellness Letter.
Houghton Mifflin Company, Boston, 1991.=20

Viral Hepatitis Prevention Board. Safety of hepatitis B vaccination program=
mes.
http://esoc-www.uia.ac.be/esoc/VHPB/statement.html=20

Whitman, Cynthia, Belgharbi, Lahevari, Gasse, Francois, Torel, Carol, Matte=
i, Vittoria, and Zoffman, Henrik. "Progress
towards the global elimination of poliomyelitis." In _World Health Statisti=
cs Quarterly, Vol 45, No 2/3, 1992.=20

WHO. The Work of WHO 1990-1991. Biennial Report of the Director General.=20

Wilkerson, James A., M.D. Medicine for Mountaineering, Third Edition. The M=
ountaineers, Seattle, Washington, 1985.=20

Williams, Amelia L., Ph.D. News and Perspectives: New Vaccines for Childhoo=
d Immunization. Drug Benefit Trends
9(3):10-11,15-22, 1997. (Found on Medscape.)=20

Wyngaarden/Smith/Bennett. Cecil Textbook of Medicine, 19th edition, 1992.=
=20

Electronic resources consulted:=20

American Association of Pediatrics Web site. http://www.aap.org=20

CDC AIDS DAILY SUMMARY (regularly posted on sci.med.aids)=20

CDC National Immunization Program Web site. http://www.cdc.gov/nip/=20

Degos, Francoise. Immunisation contre le virus de l'h=E9patite B : bilan de=
 quinze ann=E9es de vaccination.
http://www.john-libbey-eurotext.fr/articles/aB80DA9A7/index.htm=20

fdabbs.fda.gov (login using name "bbs") (more recently, http://www.fda.gov)=
=20

gopher.who.ch (gopher gopher.who.ch, also:=20

telnet gopher.who.ch login:gopher) (more recently, http://www.who.org)=20

HICNet Medical News Digest (available from LISTSERV@ASUACAD.BITNET; regular=
ly posted to sci.med)=20

Immunization Action Coalition Web site. http://www.immunize.org=20

Journal Watch Summaries (regularly posted to sci.med by jwatch@world.std.co=
m)=20

Le point sur la vaccination contre l'h=E9patite B http://www.sante.gouv.fr/=
htm/pointsur/vaccins/effets_sec_hep_b.htm=20

Levy-Bruhl, Daniel et al. Comparaison entre les Risques de Premieres Attein=
tes Demyelinisantes Centrales Aigues et les
Benefices de la Vaccination Contre L'Hepathite B. http://www.rnsp-sante.fr/=
beh/1999/9909/index.html=20

Medscape http://www.medscape.com=20

Also available on the net is the Morbidity and Mortality Weekly Report (MMW=
R). It is available by Worldwide Web at:=20

http:/www.cdc.gov/; Go to publications and scientific data, then Morbidity =
and Mortality Weekly Report, OR=20

by gopher at Duke University.=20

Morgan, Lon. Immunization, Vaccines, Vaccination in the Modern World http:/=
/fp1.cyberhighway.net/~lmorgan/=20

Swiss Medical Weekly. http://www.smw.ch=20

A list of Internet and Bitnet Health Sciences resources, compiled by Lee Ha=
ncock, can be ftped from the pub/nic directory of
ftp.sura.net.=20