News of cases of vaccine-preventable 'exotic' disease in the UK is uncommon. A UK rabies case last made the headlines in 2012. In March 2018, Public Health England warned that yellow fever had been reported in a traveller returning from Brazil, the first case in the UK since before 1996. This was also only the eighth in Europe and the US between 1996 and 2017.1

Some UK travellers may therefore question whether a vaccine is worth having, such is the low level of reported cases being brought back. Several diseases have not been recorded in the UK for years at a time (see table 1).

Table 1: Reported cases of vaccinable diseases brought back by travellers to the UK:

Disease                                                  Notes on number of cases occurring within UK

Cholera                                                  Averages around 15 cases a year in the UK, around
                                                             77% of which are thought to be linked to travel in
                                                             India.²

Hepatitis A                                             444 cases were reported in England and Wales in
                                                            2016, around 23% of which were thought to be
                                                            acquired during travel abroad.³

Hepatitis B                                             Of 11,901 confirmed infections reported in England
                                                             in 2016, 327 were classified as acute/probable
                                                             acute cases (the vast majority were chronic
                                                             infections); no data was indicated relating to
                                                             travel-related acquisition.⁴

Japanese encephalitis                             Only two cases have been documented in the UK.⁵

Meningococcal meningitis                        There were 737 cases in 2016-17 (no data on how
                                                            many were associated with travel).⁶

Poliomyelitis                                           The last imported case into the UK was 1993.⁷

Rabies                                                    Five people have had rabies in the UK since 2000,
                                                             of whom four died, resulting from dog bites when
                                                             abroad.⁸

Tetanus                                                  There were only four cases in 2016 in England.⁹

Tick-borne encephalitis                             Nine diagnoses in the UK in 2014-15.¹⁰

Typhoid fever                                          An estimated 500 cases occur in the UK annually,
                                                              often in people visiting friends and relatives in
                                                              Bangladesh, India and Pakistan, but also
                                                              elsewhere in Asia, Africa and South America.¹¹

Yellow fever                                              The case in March 2018 of a traveller returning
                                                                from Brazil was the first in the UK since 1996.¹

In contrast, there were 1,618 cases of malaria reported in the UK 2016, almost 95% of which were in England. The total was a 15.6% increase on 2015, but the 10-year annual mean has fluctuated around 1,533 cases. The current target for having a licensed malaria vaccine available is 2030, but even then it may only be 75 per cent efficient.12,13

Of course, the data in Table 1 does not indicate how many people had the relevant vaccination before travelling, so it is not apparent how many cases have been prevented.

As an extreme example of the impact of vaccination, take polio. The World Health Organization says that cases of wild poliovirus have decreased by over 99% since 1988, from around 350,000 cases then, to 22 reported cases in 2017. €As a result of the global effort to eradicate the disease, more than 16 million people have been saved from paralysis.€14

However, it warns of the need for ongoing vaccination: €Failure to eradicate polio from these last remaining strongholds could result in as many as 200,000 new cases every year, within 10 years, all over the world."