Two British people DIE after receiving yellow fever vaccines as health chiefs urge doctors to use extreme caution before giving weak holidaymakers the jab against the killer virus Two patients developed a complication called viscerotropic disease Yellow fever is spread by mosquitoes mostly in Africa and the Americas Vaccines can cause illness in some people because they use live viruses By Sam Blanchard Health Reporter For Mailonline Published: 14:51 BST, 18 April 2019 | Updated: 15:21 BST, 18 April 2019 Viewcomments Two people in the UK have died after being given a vaccine to protect against the potentially fatal yellow fever. The tropical illness is spread by mosquitoes and found in Africa, South and Central America, and the Caribbean, so the jab is recommended for people travelling to those areas. But in extremely rare cases – approximately one in a million – the vaccine can trigger viscerotropic disease, which can be deadly. Both the unidentified victims were in categories of people who shouldn't always be given the vaccine – one was aged over 60 and the other had had their thymus gland removed. Health chiefs have now warned medics to check it's safe to give their patient the jab, which can cost around £60 on the NHS, before they do so. Two patients in the UK have died after being given the yellow fever travel vaccine, which went on to cause a disease which can lead to multiple organ failure (stock image) The UK's Medicines and Healthcare products Regulatory Agency (MHRA) revealed the cases in a report this week. Both patients died 'shortly' after receiving the vaccine because of yellow fever vaccine-associated viscerotropic disease (YEL-AVD). One of them was 67 years old – the life-saving jab is not recommended for people over the age of 60, according to the NHS. It's also not recommended for people who have had surgery to remove their thymus gland, a gland in the chest which is part of the immune system. The other victim, who was in their 40s, had had this operation. CAN VACCINES MAKE YOU ILL? Live vaccines, such as the one given to protect against yellow fever, work by injecting a weakened but still living form of the virus into the body. The purpose of this is to train the body how to make the right antibodies to fight off the virus, so it can remember how to do so in future. However, if someone's immune system is weakened – by cancer, pregnancy, HIV or age, for example – it may be unable to destroy even the weakened form of the virus. If this happens, it's possible the injected virus can survive, take hold and cause the infection it was intended to prevent. If this happens the symptoms are usually milder than the real disease. People who have had live vaccines may also be able to transmit an illness to someone with a weakened immune system, so should stay away from them after the jab. Live vaccines given in the UK include those for: rotavirus, MMR, flu (nasal only), shingles, chickenpox, tuberculosis, yellow fever and typhoid (oral only). They are all proven to be effective and side effects are rare. Source: Vaccine Knowledge Project, University of Oxford Although the vaccine is known to give safe and effective life-saving protection from a deadly infection, the MHRA has warned medics to thoroughly check all patients before giving it to them. In a report it said: 'When a person presents for yellow fever immunisation, it is important that healthcare professionals clearly discuss with them the individual risks and benefits of the vaccine based on their specific travel itinerary. 'Sufficient time should be set aside to ensure that the person is immune competent and has no [reasons they shouldn't have] the vaccine, including a review of full medical history and any available medical records.' YEL-AVD triggers a similar illness to yellow fever caught from a mosquito, which leaves patients with fevers, headaches, vomiting and muscle pain. In severe cases it can progress to uncontrollable bleeding and lead to multiple organ failure and death. While wild yellow fever has a death rate of around 50 per cent among patients with symptoms, YEL-AVD kills more than 60 per cent of patients, according to the US Centers for Disease Control and Prevention (CDC). The vaccine can trigger yellow fever in people with particularly weak immune systems because it uses a live form of the virus. A healthy body destroys the weakened virus and remembers how to do it, making the person immune, but if the body is too feeble to do this the virus can take hold and trigger illness. Other people who may be too unprotected to have the yellow fever vaccine include pregnant women, HIV or cancer patients and babies under nine months old. As many as one in three people may have side effects such as headache, soreness or mild fever after having the jab, but these should pass within a fortnight. The yellow fever vaccine, known as Stamaril, is given in a single injection and is not freely available on the NHS – it usually costs between £60 and £80. Read more: Share or comment on this article: All rights reserved for this news site dailymail and under his responsibility