Travel Vaccination

This blog provides some insight and guidance into the main travel vaccines and conditions they are necessary to prevent via active (vaccination) immunity via a review of the available literature.

Hepatitis A

This is a type of viral liver infection caused by hepatitis A (HPA) virus which is widespread in other parts of the world such as Africa and India, but not the UK and Europe, with symptoms that are similar to flu and include joint aches, being or feeling unwell, and nauseous, and low-grade fever not higher than 39.5C. It is spread via contaminated food or water, and sharing of infected needles and at times unprotected sex, and confined spaces where there may be poor ventilation.  If left untreated, symptoms of liver infection set in swiftly which can last anywhere from 2 to 6 months and worsen with age, and include abdominal pain, itchy skin, pale stools, jaundice (a yellowing of skin and white of the eyes) and dark urine. In most cases, the liver makes full recovery with analgesics (paracetamol within recommended doses), antiemetics to alleviate feelings of sickness and rest.

Vaccination is recommended for high-risk occupational jobs such as sewage workers, travellers to Africa, India, Pakistan, and parts of South America and the Middle East.  Your local pharmacy will have the latest travel vaccination charts.

Havrix Monodose is an effective vaccine against hepatitis A and contains 1440 ELISA units/mL of inactivated adsorbed virus and is administered intramuscularly to adults and children over 16 years as a single dose, repeated 6-12 months later.  Children under 16 receive half the adult dose at the same frequency, and the booster dose may be delayed by up to 3 years.

Hepatitis B

In many respects, hepatitis B is far more serious than hepatitis A and can become acute or chronic.  It is an infectious inflammatory illness of the liver caused by the hepatitis B virus(HPB) and inflicts damage by replicating in hepatocytes and interfering with normal liver functions.

The virus is transmitted by exposure to infectious blood or body fluids such as semen and vaginal fluids, while viral DNA has been detected in the saliva, tears, and urine of chronic carriers. Prenatal infection is a major route of infection in endemic (mainly developing) countries.  The hepatitis B virus is 50 to 100 times more infectious than HIV and some 350 million people around the world are seropositive (carriers).

Other risk factors for developing HBV infection include working in a healthcare setting, transfusions, dialysis, acupuncture, tattooing, sharing razors or toothbrushes with an infected person, travel in countries where it is endemic, and residence in an institution.

However, hepatitis B viruses cannot be spread by holding hands, sharing eating utensils or drinking glasses, kissing, hugging, coughing, sneezing, or breastfeeding.

The acute illness causes liver inflammation, vomiting, and jaundice similar to hepatitis A, but rarely death.  Chronic hepatitis B may eventually cause cirrhosis of the liver requiring a liver transplant, and/or liver cancer. The infection is treated predominantly with alpha-interferon preparations, and it is preventable by vaccination (Engerix B, a suspension of surface antigens at a potency of 20mcg/mL).  It is administered by intramuscular injection involving three injections with the first dose at time 0, a second dose 1 month later and a third dose 6 months after the first one.  Children 1 month to 16 years old, receive three doses as above at 10mcg/mL.

Cholera

This is a bacterial infection in the intestine caused by drinking water contaminated with vibrio cholera bacteria, or by eating food that has been in contact with contaminated water.

A rapid dip-stick test is available to determine the presence of V. cholerae.  The most common symptoms of cholera are extensive, watery diarrhoea, nausea (feeling sick), vomiting (being sick), muscle cramps.  Left untreated the combination of diarrhoea and vomiting can cause a person to quickly become dehydrated and go into shock experiencing a sudden massive drop in blood pressure. In the most severe cases, these conditions can be fatal.  Around three-quarters of people who are exposed to cholera bacteria do not develop any symptoms. However, these people can contaminate water by passing stools (faeces) that contain bacteria into water or pass on the disease through poor food hygiene. Because of the improvements in sanitation and water hygiene over the last 100 years or so, cholera has been wiped out in England and much of the rest of the world.  There has not been a case of cholera in England since 1893. All reported cases of cholera in England are as a result of people catching the infection while travelling abroad.

Cases of cholera are now largely confined to regions of the world with poor sanitation and water hygiene, such as sub-Saharan Africa (all the countries south of the Sahara desert), south and south-east Asia, particularly India and Bangladesh, some parts of the Middle East, some parts of South America. However mass outbreaks have occurred in times of natural disaster, war, or civil unrest due to overcrowding in poor living conditions and lack of clean water.

Advice for travellers is if you are travelling to parts of the world known to be affected by cholera, following some basic precautions should prevent you from contracting a cholera infection:

• maintain good personal hygiene
• only drink water from a bottle that has been properly sealed or carbonated
• do not buy ice cream, ice cubes or fruit juices from street vendors
• do not eat raw vegetables, peel fruit before eating, shellfish or salads

Travellers who do contract cholera tend to have a much better outlook as they are generally healthy and well-nourished which sadly is something that cannot be said about natives of many developing countries.

Cholera needs prompt treatment with oral rehydration solution (ORS) to prevent dehydration and shock. ORS comes in a sachet. It is made up of a mixture of salts and glucose, which are dissolved in water. ORS is ideal for replacing the fluids and minerals that are lost when a person becomes dehydrated. ORS sachets are available from your local pharmacies (Dioralyte), camping shops and travel clinics. If you are travelling to regions of the world affected by cholera, take ORS sachets as a precaution.

As well as treating dehydration and shock with ORS, antibiotics can be used to treat the underlying infection. Antibiotic treatments for one to three days shorten the course of the disease and reduce the severity of the symptoms. Use of antibiotics also reduces fluid requirements. People will recover without them, however, if sufficient hydration is maintained. Doxycycline is typically used the first line, although some strains of V. cholerae have shown resistance. Other antibiotics proven to be effective include cotrimoxazole, erythromycin, tetracycline, chloramphenicol, and furazolidone. Norfloxacin also may be used, but resistance has been reported.

There is a vaccine (given as an oral suspension) that protects against cholera and is approximately 85% effective.  Dukoral is diluted with effervescent sodium bicarbonate granules which contain the Inaba and Ogawa strains of vibrio cholera bacteria as well as recombinant cholera toxin-B subunit.  The NHS advice is that vaccination is usually only required for people travelling in remote areas where cholera epidemics are occurring and there is limited access to medical care, those intending to visit high-risk areas such as refugee camps or war zones, those taking part in disaster relief operations to include emergency relief workers, members of the armed forces and healthcare workers.

 Diphtheria

Vaccination against diphtheria is part of the routine childhood immunisation schedule; Children should receive five doses of the diphtheria vaccination which is usually combined with other vaccines. Five doses provide a good level of protection against diphtheria in most cases. All babies should be given the combined DTaP/IPV/Hib vaccine when they’re two months old. This also vaccinates against tetanus, whooping cough, polio, and Haemophilus influenzae type b (Hib).

This vaccination is followed by two more booster doses which are given at three months and four months of age. Another booster dose of DTaP/IPV is also recommended for children who are about three years and four months old (the pre-school booster). This protects against diphtheria, tetanus, whooping cough and polio. A final booster dose of Td/IPV should be given to children when they’re 13 to 18 years old. This protects against diphtheria, tetanus and polio.

Further booster vaccinations may be required if you’re going to live or work in parts of the world where diphtheria is widespread, especially if your last dose was more than 10 years ago.

Regions known to have high rates of diphtheria include:

• Sub-Saharan Africa (all the countries to the south of the Sahara Desert, particularly Nigeria)
• India
• Nepal
• Bangladesh
• Indonesia
• Philippines
• Vietnam
• Laos
• Papua New Guinea
• Brazil
• Iraq
• Afghanistan

The risk of developing a diphtheria infection in the UK is very small and so additional booster doses of the vaccine aren’t usually required. However, if you have a job that puts you at increased risk of infection, such as working at an infectious disease unit or a microbiology laboratory, you may need to have additional vaccinations.

After having the diphtheria vaccine, temporary soreness, redness or even a small lump may also form at the injection site but this disappears within a few weeks. Severe reactions are very rare.

Post Polio Syndrome is a poorly understood condition that can cause pain, muscle weakness and fatigue.

Since 1998, no cases of polio have been reported in the UK. There are now only four countries in which the condition remains a serious problem and these are Nigeria, India, Afghanistan, Pakistan.

There is no cure for polio so it is important to prevent it from occurring.

Tetanus

The tetanus vaccine forms part of the combined DTaP/IPV/Hib vaccination which as stated above also offers protection against  This provides protection against diphtheria, pertussis, polio, and Haemophilus influenza type b (Hib).

It is recommended that the DTaP/IPV/Hib vaccination is given to babies at two, three and four months of age. However, it can be given at any stage between two months and 10 years of age.

The first course consists of three doses of the vaccine. The doses are given one month apart. If this course is interrupted, it should be resumed (but not repeated) with an interval of one month between the remaining doses.   Avoid repeat doses in children who have had a severe allergic reaction (anaphylaxis) to a previous dose or to any of the components of the vaccine. Children should be non-febrile, but no reason not to give the combined vaccines if they have a cough or cold.  Within 12 to 24 hours of having the DTaP/IPV/Hib vaccine, your child may experience some mild side effects, including:

• swelling and redness at the site of the injection
• a small lump at the site of the injection, which may last for a few weeks
• a slightly raised temperature
• some sickness or diarrhoea
• your child may be irritable and miserable

In very rare cases (less than one in 1,000), babies can have more serious side effects around 24 to 48 hours after receiving the DTaP/IPV/Hib vaccine, including very high temperature, febrile convulsions, high pitch cry, less alert than normal or floppy.

Children under the age of 10 should be given the first tetanus booster combined with diphtheria, pertussis and polio vaccines (DTaP/IPV). Ideally, the first tetanus booster should be given three years after the initial course is completed. This is usually when a child is three-and-a-half to five years of age. so the DTaP/IPV vaccine should be given to children under the age of 10.

If the initial vaccination was delayed, the first booster dose can be given at the scheduled time, as long as the last dose was given at least one year before. This allows the child to get back on to the routine schedule.

Children over the age of 10 who have had three doses of the primary vaccination, with the last dose received at least five years ago, should be given the first tetanus booster combined with diphtheria and polio vaccines (Td/IPV).

Ideally, the second booster dose (Td/IPV) should be given 10 years after the first booster dose. However, if previous doses were delayed, the second booster dose can be given at the scheduled time, as long as at least five years have passed since the first booster dose was given. This is the last scheduled opportunity to ensure long-term protection.

Td/IPV is recommended for children between 13 and 18 years old. Td/IPV is a booster vaccine that tops up protection against tetanus, diphtheria, and polio.

Tetanus vaccination is usually recommended for anyone who has not been vaccinated before, has not been fully vaccinated (in the UK you should receive five doses of the tetanus vaccine) or is travelling to a country with limited medical facilities, and whose last dose of the tetanus vaccine was more than 10 years ago.

Meningitis B

In January 2013 a new meningitis B vaccine called Bexsero was licensed by the European Commission. This means the vaccine should become available for use in the UK.  The most popular vaccine preparation is called ACWY Vax, administered by deep subcutaneous injection after being reconstituted  Adults and children over 5 years get a single dose followed by a booster dose every 5  years if at continued risk.

High-risk areas include parts of Africa and Saudi Arabia. Therefore this is highly recommended for those staying for longer than one-month backpacking, living with locals in rural areas attending the Hajj or Umrah pilgrimages (religious journeys to Mecca, the centre of the Islamic world) in Saudi Arabia, doing seasonal work in the Hajj area of Saudi Arabia.

Visitors arriving in Saudi Arabia for the Hajj and Umrah pilgrimages, and seasonal workers in the Hajj area, require proof of vaccination against groups A, C, Y and W135 meningitis.

The meningitis vaccine is not suitable for babies younger than two months old.

About 10% of people experience soreness and redness at the injection site after having the ACWY vaccine to protect against groups A, C, W135 and Y meningitis. This usually lasts around 24-48 hours. Mild fever can also occur (this is usually more common in young children than in adults). Severe reactions are very rare.

Typhoid

Typhoid is found throughout the world but is more likely to occur in areas where there are poor sanitation and hygiene. In particular, risk areas include:

• Africa
• Central America
• The Indian subcontinent
• The Middle East
• South America
• South and Southeast Asia

In particular, typhoid vaccination is recommended for people who will be staying with or visiting local people, and have frequent or prolonged exposure to conditions where sanitation and food hygiene are likely to be poor.  In England, most people who get typhoid fever have visited India, Pakistan and Bangladesh. Therefore, it is particularly important that you are vaccinated if you are visiting these countries.

Two types of vaccines are available for typhoid fever:

• VI vaccine (Typhim Vi and Typherix) – this is thought to be 75% effective against typhoid fever in the first year after vaccination. These are administered as 0.5ml pre-filled syringes at least 2 weeks before exposure (travelling).
• Ty21a vaccine (Vivotif) – this is thought to be 50-60% effective against typhoid fever in the first year after vaccination.  It is taken an hour before a meal on days 1, 3, and 5.  Capsules should be stored in the fridge. 

While the VI vaccine is more effective, some people prefer to have the Ty21a vaccine because it is available as a tablet, while the VI vaccine is given by injection.

However, as the Ty21a vaccine contains a live sample of Salmonella typhi bacteria, it is not suitable for people who have a weakened immune system (the body’s natural defence against infection and illness), such as people with HIV.

The protective effect of the VI vaccine will last for around three years, after which a follow-up booster vaccination will be required. The Ty21a vaccine will last for around one year before a booster shot is required.

Varicella-Zoster Vaccine

In childhood this virus variant causes chickenpox, but it never disappears (remains dormant in the nervous system) so later in life when its reactivated, it either brings on chickenpox with severe symptoms or causes shingles.  In childhood, its serious complications can be encephalitis or pneumonia. In either case, its dermatological manifestations are fever, weakness and painful fluid-filled pustules. It is actually related to the herpes simplex virus family.

Treatment is very effective antivirals such as aciclovir, famciclovir, and valaciclovir, usually at various potencies taken five times a day for 5 to 7 days. 

Varivax is the most widely used vaccine used to confer immunity, but there have been concerns raised that its protective effect wanes with age.

It is administered by intramuscular injection into the deltoid muscle of adults or the upper thigh area of children; Adults and children over 13 years receive two 0.5mL doses separated 4-8 weeks.  Children 1-13 years receive two 0.5mL doses at least 4 weeks apart.

Yellow Fever

Please view map via this link: www.nathnac.org

This is a tropical disease transmitted via mosquito bites (Aedes aegypti) resulting in what is referred to as viral haemorrhagic fever, a rapidly progressive toxic phase with multiple organ failure – liver (hepatitis), renal failure, haemorrhagic and cardiovascular shock.  Despite the availability of a vaccine since the 1950s, there are still nearly 30,000 deaths per year from Yellow Fever, and an estimated 220,000 cases globally.  One problem is there is no effective treatment available and prevention remains the main strategy in combating this in both rural and urban areas.

Yellow fever is endemic in many parts of sub-Saharan Africa and tropical South America, where both sporadic cases and epidemic outbreaks may occur. Yellow fever is rare in travellers to these regions and, since 1996, there have been just six fatal imported cases in European and US travellers. All were in unvaccinated travellers. Yellow fever vaccination is recommended for travel to all countries in the endemic zones, whether or not an international certificate is required, and especially in rural areas will be visited. Your local pharmacy can provide up to date advice on the latest requirements.

The Yellow Fever vaccine is not available through through the NHS so visit a local travel clinic.

The 17D-204 strain live attenuated vaccine (Stamaril) has been one of the most successful antiviral vaccines to date and over 600 million doses have been used worldwide. Wherever high vaccination rates (>80%) have been achieved the incidence of yellow fever has declined. However, whilst the majority of countries with endemic yellow fever do have vaccination programmes, few achieve vaccination coverage of more than half of their population.  Furthermore, expansion of travel to these areas has increased demand for the vaccine and every year there are shortages.

Vaccination Schedule: It is administered as a single dose by deep subcutaneous route over 9 months and provides immunity in 95-100% of travellers. It should be given at least ten days prior to travel to the endemic area to allow sufficient immunity to develop. Immunity probably persists for life, but re-vaccination is advised after 10 years for those whose risk of contracting the disease persists.  The vaccine can only be given at specialist centres. Proof of yellow fever vaccination, recorded on an International Certificate of Vaccination, is now the only vaccination certificate that should be required in international travel. Many countries require this of travellers, including those in transit, arriving from infected areas or from countries with infected areas. Some countries require evidence of vaccination from all entering travellers, even when they have come directly from a non-endemic country. This can be strictly enforced, particularly for people arriving in Asia from Africa or South America. Failure to comply may result in being quarantined for several days. The certificate is valid from the tenth day after primary vaccination and lasts for 10 years. The certificate is also valid immediately after re-immunisation if the re-immunisation occurs within the 10-year period. If vaccination is contra-indicated, the dispensation is possible and an exemption certificate of WHO standard should be issued.  Live vaccines can be given at the same time as inactivated ones. Other live vaccines can be administered at the same time as the yellow fever vaccine but must be given at different sites and in different syringes. If other vaccines are not given on the same day, they should be separated by an interval of at least three weeks. It is good practice to obtain written or verbal consent, prior to vaccination. Patient details, together with the date, time, batch number and site of vaccination should be recorded, and an immunisation certificate issued, which is signed by the patient and stamped by the issuing centre.

The following groups of people should be immunised:

• Laboratory workers handling infected material.
• Persons aged nine months or older who are travelling to countries that require an International Certificate of Vaccination for entry.
• Persons aged nine months or older who are travelling to or living in infected areas or countries in the yellow fever endemic zone even if these countries do not require evidence of immunisation on entry.
• Tree cutter in tropical regions.

Contraindications: egg allergy, infants 5 months and under, infants 6-9 months only if the benefit outweighs the risk, those with thymus disorders, the immunocompromised either congenitally or acquired, those 60 and over, and avoid in pregnancy because of risk of fetal infection from live virus vaccine.  World Health Organisation recommends the vaccine may be considered after the sixth month of pregnancy and should be administered if the destination risk is high.

The most serious reported adverse reaction is (Yellow Fever vaccine-associated viscerotropic disease (YEL-AVD). This can occur 2-7 days after vaccination and typically patients develop fever, malaise, headache and myalgias and then progresses to hepatitis and multi-organ failure, like wild-type yellow fever.  It also has similarly high fatality rates. It is extremely rare (three cases per million doses of vaccine).  A safer inactivated yellow fever vaccine is being trialled which could be useful for vaccinating people at higher risk of adverse events from the live vaccine.

Japanese Encepahlitis

The Japanese Encephalitis vaccine (Ixiaro) should be given to travellers to endemic areas of Asia and the Far East, and for laboratory staff at occupational risk. The primary immunisation course of 2 doses should be achieved at least one week before potential exposure.  Administration of vaccine is by intramuscular injection in the deltoid region in adults and those 18+, two doses of 0.5mL separated by a 28-day interval. and a booster dose 1-2 years after completing the primary course (at the 1-year interval for those at continuous risk).  Again, there is no specific treatment available.

The non-specific symptoms of Japanese Encephalitis are fever, headache and malaise which may last for 1 and 6 days. Other more serious signs that develop during the acute encephalitic stage include neck rigidity, cachexia, hemiparesis, convulsions and a raised body temperature between 38 and 41 degrees Celsius (100.4 and 105.8 degrees Fahrenheit).  Mental retardation developed from this disease usually leads to coma.  Domestic farm pigs and birds (herons) are common carriers.