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How Long Do Travel Vaccinations Take To Work?

Updated: Jun 28

Summer is the time that we all begin to think about our holidays. There's lots to think about, like clothes shopping, what to pack and what to do when you reach your destination. However, there’s one thing you should be thinking about early in your planning process, and that's your travel vaccinations.

How long do travel vaccinations take to work?

Your holiday vaccinations will help protect you from a variety of diseases that you may encounter, particularly if you're travelling to exotic destinations in the tropics. There's nothing worse than falling ill during the holiday of a  lifetime. Suddenly, what seemed like paradise has become a strange place in unfamiliar surroundings with people  you might not know. Worse still, where do you seek for medical help, and how do you know they’re reliable?

In this article, we’ll help you plan for your travel injections and offer top travellers tips to help you get organised.

By the end of the article, you should become aware of:

  • How health professionals, such as your  GP or an independent travel clinic can support you through this process

  • The effectiveness of vaccines 

  • The safety that travel vaccinations can provide for you and therefore the peace of mind that you need before you travel.

So why are travel vaccinations recommended and do they actually work?

To answer this question, we need to understand how our immune system works.

Your immune system is composed of innate and adaptive immunity. 

Innate immunity

Innate immunity is, as the name suggests, something that you are born with and consists of all the different ways your body can try and protect you from all sorts of viruses, bacteria, fungi and parasites. It's not specific to any particular microbe and aims to protect you against a wide variety of infections that you might encounter. Examples of your innate immunity include your skin which acts as a protective barrier, as well as the lining of your nose and airways. Some white blood cells like neutrophils in your bloodstream can scavenge and kill any bacteria once they invade the body.

Adaptive immunity

The adaptive immune system, on the other hand, is much more specific to a particular bacteria or virus and takes time to develop. One particular type of white blood cell in your bloodstream, called the lymphocyte, acts as the main conductor in the orchestra of adaptive immunity. Lymphocytes produce antibodies that are specific to a particular bacteria or virus. These specific antibodies can protect you from infection in a number of ways. They can neutralise toxins, or stop bacteria from attaching themselves to healthy human cells and therefore preventing any damage. Some lymphocytes can even orchestrate and coordinate other immune cells within the bloodstream to kill the offending, alien microbe.

How does your immune system protect you when you receive a vaccine?

When you receive a vaccine, it’s usually made-up of a fragment of the bacteria or virus, or the whole cell. This is what we call the ‘antigen'. They can be killed or inactivated, or in some cases, they can be a weakened form of the virus or bacteria. Once you receive the injection, the vaccine is carried from tissues to your lymph glands where they encounter these lymphocytes. It takes a bit of time to find the lymphocyte with the correct ‘fit ‘ for the vaccine antigen. This is why it takes time for the vaccines to work. There are millions and millions of lymphocytes but only a few will be able to produce effective antibodies against that particular vaccine. However, once the unique lymphocyte is located, it will produce lots and lots of antibodies because the vaccine is essentially mimicking the real infection.


Some vaccines have more than one dose and the purpose of booster doses is to stimulate the production of what we call memory lymphocytes. These are lymphocytes that remember that particular vaccine antigen and can produce antibodies very quickly should your body encounter the real infection in the future.


If that was all a bit too much for you, don't worry, here’s a nice video of how vaccines work.

So, when you receive your travel injections, the body's adaptive immunity (lymphocytes) produces lots of antibodies to protect you. Common travel vaccines like hepatitis A, yellow fever and hepatitis B are highly effective in protecting you from infection.

So when should I get my travel vaccinations for maximum vaccine effectiveness?

Now that we've understood how our body’s immune system reacts to vaccines, we can see how it takes time to see a response. This means you should plan ahead and leave plenty of time to give your lymphocytes the time they need. As a rough rule of thumb, single dose vaccines like typhoid, diphtheria, tetanus and polio will achieve maximal effectiveness after about a month following vaccination. This means you should ideally get your holiday vaccinations started at least for six weeks before you plan to travel.

Does that mean I shouldn't bother if I've left it too late? No, not at all. You can produce decent levels of antibodies within the first four weeks following your travel injections. For example, you'll achieve a four-fold rise in antibody levels after seven days following the typhoid vaccine. The hepatitis A vaccine is effective within two weeks but you'll still get some protection before. With the yellow fever vaccine, you will get protective levels of antibodies within ten days of vaccination.

If you’ve left it until the last minute, it’s still worth receiving your travel vaccinations (even if it’s within a day of travel), as you will be partially protected.


Below is a brief summary of vaccine effectiveness of some common travel injections


Time to adequate protective levels

Time to maximum vaccine effectiveness


7 - 14 days (at least 4 fold rise in antibodies)

1 month

Hepatitis A

14 days

1 - 6 months

Hepatitis B

56% effectiveness at 2 months

>90% effectiveness at 7 - 8 months



>95% effectiveness at 3 - 4 weeks

Yellow Fever

10 days

1 month


The above table is a rough guide to help prepare for your holiday vaccinations. Remember, vaccine effectiveness is dependent upon a number of other factors like your age (generally older people respond less well), other medical conditions that you may have or if you have a weakened immune system, for example if you've had chemotherapy or have HIV infection.

So where can I get my travel vaccinations?

Some GPs do offer free travel vaccinations but make sure that you book well ahead as they often need several weeks’ notice. Free vaccinations include typhoid, hepatitis A and tetanus but other travel vaccinations such as rabies and yellow fever are chargeable.


Independent travel clinics such as Health Klinix can offer expert advice on not just your holiday vaccinations but they can offer comprehensive advice on diseases that cannot be protected by vaccines. Some pharmacies also offer travel vaccinations but it's important to make sure that wherever you go, the advice you receive is of high quality and offered by experts in travel medicine.

Practical tips for planning your holiday vaccinations


You've booked the holiday of your lifetime and often at great expense, so you want to make sure that you are going to be safe and have a stress free holiday. Just like the itinerary, your travel injections also require some planning in advance.


Here's a suggested timeline of things you should be doing to ensure you get your travel vaccinations in good time and maximise their effectiveness:


6 months before travel

Book your holiday tickets. This is the fun part!


4-6 months

Plan your itinerary.

For example, will you be having a resort type holiday or will you be backpacking? Will you be mainly in cities sightseeing or do you intend to venture off the beaten track and travel to remote areas? This is particularly relevant in the tropical regions of the world.


3 months

Contact your GP as they may be able to offer you some free vaccinations. You can request your vaccination summary records from the GP reception staff . You shouldn't have to see your GP for this as they should easily be able to print this out from your online medical records. This vaccine summary record will prove very useful when you then go and see a travel clinic for any further travel health advice and vaccinations. You'll also need to gather any other vaccine record cards that you may have for previous vaccinations from other private travel clinics.


2-3 months

Contact your travel clinic and arrange a consultation. Health Klinix charges a very nominal consultation fee for a high quality, consultant led travel health service. Just remember to book well  in advance as some vaccinations such as rabies and Japanese encephalitis vaccine schedules consist of several doses over a month.

Don't worry if you’re calling us last minute because we can usually offer accelerated courses to speed up the process, and advise on vaccine effectiveness.


So to summarise, make sure you start planning early for your holiday vaccinations and in doing so you’ll know that you’re travelling safely. Remember, the whole point of your holiday is for you to relax and enjoy, so call your travel clinic in good time to get the travel health advice you need.


If you would like to learn more about the travel vaccinations, why don't you call our friendly and knowledgeable staff on 02476 016519 or alternatively you can book online at a time that's convenient to you. To help you work around your busy schedule we can offer a choice of telephone, video or face to face consultations. If you request an in-clinic consultation, it does have the advantage of you being able to receive your vaccinations at the same time as your consultation.


Health Klinix can help travellers with their vaccinations and at the same time offer comprehensive travel health advice.


  1. The Green Book. Immunisation against infectious disease

  2. The Electronic Medicines Compendium. Summary of product characteristics for hepatitis A, diphtheria, polio and tetanus, hepatitis B, rabies and yellow fever

  3. The Oxford vaccine group. How vaccines work

Reviewed and approved by:

Dr Ravi Gowda, Consultant in Infectious Diseases and Travel Medicine



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