The Measles crisis continues in many countries around the world. The disease is so contagious that 9 out of every 10 nonimmune people will be infected through contact with one infected person. Prior to the introduction of the live Measles vaccine in 1963, major epidemics were frequent and led to an estimated 2.6 million deaths a year.

To celebrate World Immunization Week and its theme for this year Protected together: Vaccines work! we are taking a look at how routine immunizations (like the Measles vaccine) impact global and travel health and how travellers can ensure they are adequately protected.

The resurgence of Measles

Global efforts to eliminate Measles have been ongoing since 2001 when the United Nations initiated a coordinated effort to address the disease. This led to an 80% reduction in Measles cases between 2000 and 2016. However, cases increased in 2017 and have continued to increase ever since.

Measles is a highly infectious disease spread through coughing and sneezing. The virus can stay active for up to 2 hours in air droplets – meaning that you don’t need to be in direct contact with a Measles-infected person to be exposed to the virus.

Recent Measles outbreaks have occurred for a number of complex reasons including limited healthcare coverage, a lack of access to vaccines, and changes in attitudes towards vaccines and vaccine safety. Vaccine hesitancy is a growing global concern; so much so that the World Health Organization (WHO) listed it as one of the top ten threats to global health for 2019.

Measles outbreaks are now being reported in every region of the world – from low income countries with low vaccination rates, such as Madagascar and the Democratic Republic of the Congo, to high income countries with high vaccination rates, such as the United States, Switzerland, and Japan. In countries with typically high vaccination coverage, the virus has been spreading among unvaccinated and under-vaccinated people.

The ease at which Measles spreads makes it a prime candidate for international travel. For example, the current outbreak in New York City began with a single unvaccinated traveller who acquired the virus in Israel and returned to New York in October 2018. As of April 29, 2019, 423 people have been infected. Measles outbreaks reported in other states such as Washington, California, and New Jersey have also been traced back to unvaccinated travellers.  There have also been 41 cases in Canada this year, which have mostly been associated with international travellers.

Vaccines in a globalized world

Preventing the spread of infectious diseases is a top priority in travel health. Fortunately, many infectious diseases can be prevented through vaccination.

Routine immunizations are a series of vaccines that provide protection against serious infections such as Measles, Diphtheria, and Polio. In countries with good vaccine coverage these diseases become uncommon and in some cases, eliminated. In places where there is not widespread vaccination coverage, these diseases continue to circulate.

Herd immunity occurs when most people in a community are vaccinated, which prevents the disease from being transmitted and reaching those most vulnerable. To provide adequate protection, global vaccine coverage should be at 95%, but recently coverage has been stalled at 85%.

The spread of vaccine hesitancy has led some to decline routine immunizations for themselves and their children, despite the accessibility and proven safety of vaccines. However, refusing vaccination for non-medical reasons means the consequences of that decision are borne by others, particularly those who cannot be vaccinated such as young children, pregnant women, and immunocompromised people.

Limited access to vaccines and pockets of low immunization has also led to Measles outbreaks in several African countries, including Madagascar and South Sudan, as well as countries like Venezuela, where entire health systems have collapsed. Unvaccinated travellers can be responsible for spreading disease in the countries they visit and their community when they return home.

For healthcare systems, the costs associated with controlling these outbreaks can add up quickly. For example, the Measles outbreak in Clark County, Washington has so far caused 74 infections and cost the US government $1.4 million. For countries with overburdened healthcare systems and limited resources, responding to outbreaks can be exceedingly difficult.

Travel & vaccines

The most crucial step for any traveller is to ensure your routine immunizations are up-to-date. Vaccine coverage varies around the world and unvaccinated and under-vaccinated travellers pose a risk to their own health and the health of others.

There is no better time than now to ensure you and your family are protected.

What vaccines do I need?

This depends on your age, health status, and your vaccine history. If you have already received all the recommended routine immunizations, you may only need a Tetanus-Diphtheria booster every 10 years and Influenza vaccination every year.

Depending on your trip, you may also need travel-related vaccinations like Yellow Fever, Japanese Encephalitis, Rabies, Tick-borne Encephalitis, or Typhoid Fever. However, these vaccines should only be administered based on a health practitioner’s assessment of your individual risk. This travel health consultation considers your itinerary, the length of your trip, planned activities, your age and health status, and the accessibility of healthcare at your destination. Some countries may require proof of certain vaccines to qualify for entry such as Yellow Fever, Meningococcal Meningitis, and Polio.

Influenza vaccination is recommended for all travellers over 6 months of age, especially for children, pregnant women, persons over 65, and those with chronic health conditions such as asthma, diabetes, lung disease, heart disease, immunosuppressive disorders, and organ transplant recipients. The flu season differs in the northern and southern hemisphere – in the northern hemisphere it runs from October to May, while in the southern hemisphere it runs from April to September.

To find out what vaccinations are required and recommended for your trip, check out Country Health Advice, an online resource providing health information for all countries, and the World Immunization Chart, a downloadable PDF outlining vaccine requirements and recommendations.

I’m not sure I have all my routine immunizations. What should I do?

Contact your healthcare practitioner if you do not have all your routine immunizations or are unsure of your vaccination status. Contrary to popular belief, routine immunizations are not just for children – adult vaccination schedules and dosages are available and recommended for those who do not have evidence of immunity (such as medical records indicating previous vaccination or lab results showing immunity through prior infection). If you do not have proof of immunity, your doctor may recommend vaccination or a booster depending on your age and health status.

I got all my routine immunizations, but it was a long time ago. Am I still protected?

Many routine immunizations provide lifelong protection. If in doubt, ask your health practitioner!

Many routine immunizations are administered in a series that allow for immunity to build. For example, one dose of the MMR vaccine provides 93% protection against Measles and two doses provides 97% protection. If you suspect you have not completed the full series of all routine immunizations, contact your health practitioner. Depending on your age and health status, you can get the next dose in the series; you do not have to restart from the first dose.

Keep in mind that you will need booster doses for Tetanus-Diphtheria and Influenza. Depending on your age and vaccination status, other vaccines may be recommended. For example, older adults may be recommended the Pneumococcal Pneumonia and Shingles vaccine.

When should I get vaccinated before a trip?

You should visit your healthcare practitioner at least 6 weeks before departure to ensure your routine immunizations are up-to-date and assess whether you need any travel-related vaccines.

Depending on what vaccines you need, they may need to be administered in a series. For example, the combined Hepatitis A and B vaccine is given in three doses on day 0, 1 month later, and then 6 months later. Accelerated schedules are typically available for most vaccines.

At minimum, you should try to get all your vaccines at least 2 weeks before you depart to give yourself enough time to build up immunity.

Short on time and cash? Check out our Travel Vaccines on a Budget series for help prioritizing vaccines.

Can I get all my vaccines at the same time?

All vaccines can be administered at the same time*.  Many routine immunizations are offered as combined vaccines to reduce the number of vaccines required. Examples of combined vaccines include MMR (Measles, Mumps, Rubella) and DTap (Diphtheria, Tetanus, Pertussis).

All live vaccines (including MMR, Yellow Fever, and oral Typhoid) can be administered at the same time**. If live vaccines are not administered in the same visit, they should be separated by 4 weeks or more. Inactivated vaccines can be administered any time and following any other vaccines.

*There are only two exceptions to this in the case of high-risk patients. You can read more here.

**One exception is the oral Typhoid and Cholera vaccine. You can read more here.

---

Image by Skitterphoto, Pexels.

Article by Claire Westmacott.