Guide to Vaccines

Diseases Subject to International Health Regulations

Yellow Fever inoculation is required for all travellers in transit or going to the yellow fever endemic zones of Africa and Central and South America. There are NO yellow fever endemic areas in Asia and travellers to these areas do not require yellow fever unless they go through Africa and South America. Yellow Fever vaccine must be administered by a WHO approved vaccination centre such as our centre. Yellow fever vaccine is a live vaccine grown in eggs. It should not be given to those with cancer or to those with impaired immunity. It should not be given during pregnancy unless the risk of yellow fever is very high. It should be avoided in patients with a known allergy to eggs. Intradermal skin testing can be done to determine sensitivity in these cases. The vaccine can be given to those over 6 months of age.

A single dose vaccinates the person for 20-35 years starting 10 days after administration. Those travellers entering higher risk environments may consider re-vaccinating Yellow Fever after 20 years. Travellers with contraindications or infants under 6 months of age will be given a certificate of exemption. Side effects include (2-5%) mild headache, muscle aches, & low-grade fever 5-10 days after the shot. Less than 0.2% curtail regular activities. Immediate hypersensitivity reactions (rash, hives, asthma) are uncommon (1/130,000-250,000) and occur primarily in people with a history of egg or other allergies. Caution should used in people >65 y/o as older patients may be at higher risk of systemic adverse reactions.

WHO Map: Yellow Fever Vaccination Recommendations

The following maps are taken from WHO's International Travel and Health publication. The shaded areas represent WHO's vaccination recommendations.

This vaccine is of benefit to travellers to countries recognized as having an epidemic of meningococcal meningitis. Sub-Saharan Africa has a high risk of meningococcal disease otherwise known as the "meningitis belt". This includes countries from Senegal to Ethiopia but varies throughout the region. Consideration should be given to vaccinating those going to live or work in these areas for more than 3-4 weeks or going to higher risk situations (orphanages, hospitals, etc). Only mild reactions occur, mainly injection site pain/redness (40%) and transient fever (6%). Severe reactions are rare (1 in a million). It is effective for 5-10 years. This vaccine is required for religious pilgrimages to Mecca in Saudi Arabia.

The meningitis belt & other areas at risk for meningococcal meningitis epidemics

Disease data source: World Health Organization. International Travel and Health. Geneva, Switzerland: 2015.

The International Health Regulations abolished the requirement of a vaccination certificate in June 1973. No country should require a certificate from travellers arriving from Canada. The only persons at risk are aid workers servicing very dire conditions. This was one of the vaccines commonly demanded by corrupt border guards in developing countries in order to extract a bribe. There is an oral cholera vaccine called Dukoral, which is now used for preventing moderate to severe Traveller's diarrhea.

Polio (poliomyelitis) is a highly infectious disease of the nervous system caused by polioviruses acquired through the consumption of fecally contaminated food or water. Most cases are asymptomatic or mild, with less than 1% of cases resulting in paralysis. Polioviruses may be wild or vaccine derived. Wild cases have decreased 99% since 1988, from an estimated 350 000 cases in more than 125 endemic countries then, to just two endemic countries (as of October 2023). While the chance to acquire polio is exceedingly small for most travellers, it is recommended that travellers to at risk countries (presently Pakistan and Afghanistan) possess the International Certificate of Vaccination or Prophylaxis (ICVP) the official documentation used as proof of vaccination against a disease when a country entry requirement exists, as designated under the International Health Regulations (IHR).

The Public Health Agency of Canada recommends having an ICVP in relation to the World Health Organization's temporary recommendations to reduce the spread of poliovirus.

This can only be done at designated Yellow Fever Centres.

Routine Vaccines

In Ontario, the adsorbed vaccines for tetanus, diphtheria, and pertussis are now being used for primary immunization schedules. All travellers should have these immunizations up to date. Tetanus should be updated every 10 years. It is advisable to give a booster at 5 years if travelling to a very underdeveloped country. Diphtheria toxoid is effective for ten years. Pertussis (whooping cough) has made a comeback in Canada and it is recommended that one should receive an adult dose. Adverse reactions are usually limited to localized pain, redness, and swelling. Fever is infrequently reported. Systemic reactions are rare. Oftentimes if there is any doubt or confusion about the last booster (>10 years), we will insist on updating this vaccine.

Cost is covered by Public Health under OHIP.
If no OHIP - $50

In developing countries, measles causes significant mortality. Most persons born before 1970 are likely immune. It is advisable that travellers be vaccinated for measles due to world wide outbreaks. In Canada, measles vaccine is administered as Mumps, Measles, and Rubella (MMR) to children after 12 months of age with a booster at 4-6 years of age. Children 6-12 months old may be immunized with MMR if they will be in contact with other young children in developing countries. Children vaccinated before 12 months of age should be revaccinated at 15 months of age. Rubella vaccination should be given to all women of child-bearing age who are not immune and Mumps vaccination is recommended for adults with no history of mumps or prior immunization. Note that there have been recent Measles and Mumps outbreaks throughout Canada and USA.

The individual vaccinations are not readily available so the MMR combination is used. These are live vaccines and should NOT be used in pregnancy or persons who are immune-suppressed. Most frequent adverse reactions are malaise, fever, and rash lasting up to 3 days (starting 7-12 days after the shot). One in 3000 children with fever may have febrile convulsions.

Cost is usually covered by Public Health under OHIP but due to shortages - $50

Influenza vaccine: the dreaded influenza affects many people each fall and winter with symptoms of fever, chills, body aches, headache, dry cough, fatigue, etc. The most seriously affected are the very young, immunocompromised and the elderly leading to hospitalizations and even deaths. Most healthy adults question the value of this vaccine but in preventing and lessening the symptoms of the flu, the numbers of days lost from work and the overall economic impact is significant. Another consideration for ‘healthy adult patients’ is that they are the very population that mounts the strongest immune response to the shot. Their strong response confers better herd immunity thus protecting the very populations (young, old, and ill) that are less likely to mount a good immune response. They act as a good Samaritans in protecting those who can least protect themselves. If you are in contact with vunerable populations (young, old, and immunocompromised) then it is your responsibility to get a flu shot to protect your ‘loved ones’. around you. The flu vaccine is adjusted yearly and includes the 3-4 most prevalent strains. Experts have a difficult decision in deciding which strains to include in each vaccine but have gotten it right more often than wrong in recent years. A significant study done in Hong Kong showed elderly recipients of both the flu and pneumonia vaccines had significantly fewer cardiac events and DEATHS (33-48%) than unimmunized populations (Clin Infect Dis. (2010) 51 (9): 1007-1016). The explanation is that infections causes inflammation of all your vessels and may exacerbate underlying coronary and vascular disease!

Flu shots are available in October and have maximal coverage for 4-5 months. There is a High Dose Flu Shot for seniors that significantly boosts the immune response (25-35% boost). Most common side effects of the vaccines are injection site pain and possible low grade fever and aches.
Remember, the flu shot DOES NOT cause the flu!!
In light of COVID, the need to take any preventive vaccine has been highlighted. The same rationale for getting an earlier COVID vaccine applies to receiving a flu vaccine - preventing the deaths of a significant number of people every year (5900 Canadians in 2020).

Recommended Vaccines

Hepatitis A is the most common vaccine-preventable illness that travellers should be protected against. It is worldwide in distribution. The infection is spread by close contact with infected individuals or contact with contaminated food and water. Prevention by ensuring clean food and water are your best defense but an effective and well-tolerated vaccine exists. Two doses six months apart should provide at least 10 years of protection but is probably valid for life. Protection may last 5-10 years after the initial dose alone. Side effects are infrequent and usually very mild (sore injection site). Persons who were born and raised in areas with high risk of hepatitis A are likely immune.

Children in developing countries usually have mild symptoms and may be unaware that they are immune. Any history of jaundice as a youth is most likely hepatitis A infection. Infection confers lifelong immunity. We can verify immunity with a simple blood test. Immune globulin (passive immunization) is still used in developing countries to counter hepatitis A and is fraught with a high risk of contamination (including HIV). This is probably the single most important vaccine for travellers as it can occur at any level of travel (backpackers to luxury resorts/business travel). World Health Organization makes a rare blanket recommendation that "all non-immune travellers (should receive this vaccine) when travelling to countries or areas at risk" (i.e. developing countries).

Typhoid is a febrile illness caused by the bacteria Salmonella typhi. It is transmitted by 'unclean' food and water. Distribution is worldwide with particular prevalence in Africa and Asia especially the Indian subcontinent. Those at particular risk are backpackers, rural travellers, 'adventurous eaters' (markets, street vendors, and home/local restaurants), and 'VFRs' ("visiting friends and relatives"). Persons with reduced gastric acid should also be wary of typhoid, e.g. "heartburn" patients on treatment. Typhoid vaccines confer between 50-80% immunity. They will only protect against a moderate amount of ingested bacteria. There are 2 types of typhoid vaccines.

A live oral vaccine, Vivotif, is a series of 4 capsules taken over one week, which should not be taken with antibiotics or antimalarials. They must be ingested on an empty stomach and be refrigerated. Adverse effects include diarrhea (5%), vomitting (2%), and low grade fever (2%). An injectable vaccine Typhim Vi can be given as a single dose. Side effects are mild: injection site reaction (4%) and fever (1%).

Vivotif confers protection for 5 years and the Typhim Vi lasts 2 years.

Infectious diarrhea is the most common ailment that will affect the traveller (up to 60% with at least 20% confined to bed for a day). Attention to "safe food and water precautions" will minimize the chance of traveller's diarrhea. Despite best medical advice, the average tourist will forget/neglect the food/water precautions within 2 days of their holiday and put themselves at risk! There is a cholera vaccine Dukoral which covers Enterotoxic E. coli (ETEC), a major pathogen for moderate to severe traveller's diarrhea. In the Caribbean, ETEC accounts for 29-72% of all bacterial diarrhea. This vaccine is a series of 2 doses taken a week apart starting at least 2 weeks before departure. This confers protection against ETEC for 3 months and cholera for 2 years. A single booster dose within 5 years of the original 2 dose series will give 3 more months of protection against ETEC. This is a great vaccine for my Mexican ‘Snowbirds” since they usually spend 3-4 months down south. Side effects are rare (nausea, abdominal pain, diarrhea) and severe reactions (headache, dizziness, shortness of breath) occur <1/100,000..

Hepatitis B is a world wide disease with carrier rates from 0.1 to 15% in various populations. The transmission of hepatitis B can be by inoculation with a contaminated needle, blood transfusion, sexual contact, intimate physical contact, and indirect routes such as shared razors or lip balm. Vaccination is recommended for all at-risk persons at any age. The risk depends on destination and occupation. Health care workers should be immunized if they are likely to come in contact with blood. Missionaries, diplomats and military personnel should be immunized if they plan to reside more than 6 months in areas with high levels of endemic hepatitis B and will have close contact with the local population. Ontario's immunization program provides 2 'adult' doses to school age kids in grade 7 so anyone who attended grade 7 (age 12) in Ontario since 1994 onwards (under 41 y/o) has been immunized for Hepatitis B.

Most adults over the age of 40 will not have received the hepatitis B vaccine but may be at significant risk of exposure to the virus depending on their habits/practices and extent of travel. The sentiment of this office is that ALL Ontario residents should be immunized for hepatitis B especially those travelling internationally.

Keep in mind that motor vehicle accidents and high risk activities are some of the major reasons that would force a traveller to seek medical attention and/or cut short their trip. More importantly, many clinics/hospitals in developing countries do not routinely screen their blood and may use unsterilized needles and instruments - a significant health threat. Immunization involves a series of three shots at 0, 1, and 6 months. An accelerated series is available for travellers rushed for time (0, day 7 day, day 21-28 & 12 months). The shots are extremely well tolerated and adverse effects are rare.

For those travellers who desire both hepatitis A and B coverage, Twinrix provides the ideal vaccine. Dosing schedule is similar to 2 of the options for hepatitis B (0, 1, 6 months and 0, 7 days, 21 days & 1 year). The 3 dose schedule basically saves you half the cost of hepatitis B compared to having to do both hepatitis A and B separately. There is another dosing option for children aged 1 to 15 years with 2 "adult" doses given 6-12 months apart. There is a schedule for infants age 6–11 months going to high risk areas: 1 dose before departure; revaccinate with 2 doses (separated by at least 6 months) between age 12–23 months.

There are no significant side effects.

Rabies is a worldwide concern. Keep in mind that there is no reliable data on the number of cases in developing countries. Further complicating matters is the fact that few countries have adequate public health care systems to isolate and test suspected animals. High Risk are those who are likely to come in contact with wildlife (veterinarians, expatriate children) and should be immunized. More importantly and thought provoking are those at Moderate Risk - adventurous travellers that are "off the beaten path” or far from adequate medical care. Remember that most developing countries have spotty health care. Another complicating factor is the fact that many poor countries do not stock the Rabies Immunoglobin (immediate passive immunity to block the rabies virus from spreading) and even the regular rabies vaccine may be hard to locate. One scratch or bite from a stray dog may prematurely end your trip.

This is a valuable resource to determine whether Rabies Immunoglobin is available in the country of travel: https://www.cdc.gov/rabies/resources/countries-risk.html

Pre-exposure vaccination regimen: 3 intramuscular doses on days 0, 7, & 21-28. This provides adequate protection to generate enough antibodies to block the Rabies virus thereby negating the need for the elusive Rabies immunoglobulin. You would simply have to clean the wound well then receive two post-exposure doses - one immediately and one in 3 days.

Medical personnel, missionaries, teachers, and some children staying in endemic areas for prolonged periods of time should consider a 'TB skin test'. A traveller at high risk should have a TB skin test done prior to departure (caution should be exercised if previously immunized with the BCG vaccine). Assuming this test is negative, the traveller should be advised to repeat the Mantoux test within 2 months of returning from their trip. If the skin test turns positive, treatment will be considered depending on age and circumstance.

Cost is covered by OHIP.

This is a mosquito-borne encephalitis resulting in fever, chills, nausea, vomiting, and neurological symptoms. JEV is the most common vaccine-preventable cause of encephalitis in the local population in Asia, extending in a wide belt from Japan and northern coastal China throughout southeastern Asia and across India to Pakistan and, more recently, in Tibet and the mountain districts in Nepal. JEV is also present in Australia and throughout the Western Pacific islands, from Indonesia to Papua New Guinea and as far north as the Philippines. The disease is usually asymptomatic, but when overt encephalitis occurs, JEV is fatal up to 30% of cases. The mosquitoes are present in greatest numbers from June to October and feed from dusk to dawn. The same general protection measures used against malaria are also important in avoiding Japanese Encephalitis.

The vaccine is recommended for persons planning long-term residence in countries experiencing epidemic JEV, especially when travel is in rural areas (particularly rice fields and pig farming) and during the months of risk. Short-term travellers (<1 month) especially those staying in urban areas are at negligible risk. The one exception would be one staying for several weeks in rural settings (near rice fields). This vaccine frequently causes injection site reactions (20%). Systemic side effects are generally mild, principally headaches and muscle aches. Severe allergic reactions occur at a rate of 1/10,000 doses. The vaccine is given as a series of 2 shots at 0 and 7 or 28 days. A booster dose in 12-24 months will likely give immunity for at least 10 years.

Streptococcus pneumoniae is the most common bacterial cause of community-acquired pneumonia and remains a leading cause of serious illness (including bacteremia, meningitis, and pneumonia) among children and adults worldwide. S. pneumoniae also causes ear and sinus infections and cellulitis.

There are two vaccines available to adults – Pneumovax 23 or Prevnar 20. Pneumovax 23 is available free of charge to every senior over the age of 65 or younger adults with significant illnesses e.g. diabetes, heart disease, kidney disease, etc. It uses outdated technology that is only effective for 1-3 years and may not boost the immune response with subsequent shots. It also does not reduce carrier rates and is not as effective in protecting against deeper tissue infections. Prevnar 20 is indicated for 18+ y/o and is a more effective vaccine that lasts longer (10+ years) with subsequent doses significantly boosting the immune response. It is much more effective in treating deeper tissue infections. Prevnar 20 basically covers most of the serotypes as Pneumovax 23 but it is not covered by Public Health – cost: $150. The main complaint is injection site pain. Basically Prevnar 20 has replaced Prevnar 13 (older vaccine) and is superior to Pneumovax 23.

Indicated for travellers at increased risk of respiratory pathogens of all kinds. Also strongly indicated for immunocompromised persons and those at the extremes of age.

Shingles vaccine (Shingrix): shingles is a reactivation of past chicken pox exposure (Varicella) and presents as pain followed by a blistered rash on one side of your body typically lasting 2-4 weeks. It occurs when your immune system is weakened by physical, mental or emotional stress. The lifetime risk of shingles is 33% meaning one in three persons will get shingles. Patients suffering from shingles can only transmit chicken pox to non-immune people (mainly immigrants as 97% of Canadian adults have been exposed to chicken pox). Shingles cannot transmit shingles, only chicken pox. The main complication is post-herpetic neuralgia which is residual pain over the site long after the rash has healed. Shingrix vaccine reduces your risk of getting shingles by ~90% and reduces the risk of post-herpetic neuralgia by >90%. The vaccine is probably effective for 10+ years but surveillance studies are ongoing to determine how long the vaccine will last. Public Health now offers Shingrix for patients aged 65-70. Shingrix is indicated for anyone aged 50+ and costs $170 x 2 doses = $340 total (0 & 2-6 months). The main side effects are redness/pain at the injection site and fatigue. Rarely a chicken pox-like rash can occur.

RSV is a common respiratory virus that usually causes mild, cold-like symptoms but can also affect the lungs. Symptoms of RSV infection may include runny nose, decrease in appetite, coughing, sneezing, fever, or wheezing. Those who are elderly and immunocompromised especially those with respiratory issues may have a more serious illness. Epidemiologic evidence indicates that persons aged 60 years and older who are at highest risk for severe RSV disease and who might be most likely to benefit from vaccination include those with chronic medical conditions such as: Cardiopulmonary disease, kidney disease, liver disease, neurological or neuromuscular disorders, hematologic disorders, diabetes mellitus, immunocompromised, frail, advanced age, nursing home residents

RSV Vaccine (Arexvy): a new adjuvant vaccine similar to Shingrix. There was a 83% reduction in symptomatic RSV lower respiratory tract disease (LRTD) during the first RSV season and 56.1% during the second RSV season. Ongoing long term data is still being collected so anything beyond 2 years cannot be extrapolated. Side effects include moderate injection site pain and fatigue. The cost is $270.

Prepared by: John O. Lee, M.D., C.C.F.P., F.C.F.P., Certificate in Travel Medicine

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