Martin Gore, 67, died Thursday morning after receiving the vaccine, recommended for travelers to sub-Saharan Africa, most of South America, parts of Central America and the Caribbean. .

The Royal Marsden NHS Foundation Trust in London, where Gore has worked for more than 30 years, expressed his "deep sadness" following the announcement of his passing.

"Martin has been at the heart of Royal Marsden's life and his work in researching, treating and training our new oncologists," said the hospital in a statement. "His contribution as medical director for 10 years, director of the Royal Marsden Cancer Charity and clinician is unprecedented."

Professor Mel Greaves of the Cancer Institute, described Gore as "a force of nature, very energetic, lucid and compassionate". Allyson Kate, president of the charity Ovarian Cancer Action, said: "He was a field giant and a humorous colleague. There is no doubt that Professor Gore has improved the lives of many people. We will miss him immensely. "

Gore's death highlights the increased risk associated with the yellow fever vaccine and the population over 60 years old. Typical side effects of the vaccine include headache, muscle aches, mild fever, and injection site pain, according to the NHS.

However, vaccinations can, in rare cases, cause more serious side effects, including allergic reactions and problems affecting the brain or organs. The NHS estimates that these reactions occur less than 10 times per million doses.

The WHO reported that all cases of viscerotropic disease – a rare but dangerous side effect of yellow fever vaccinations when a disease similar to wild-type yellow fever proliferates in multiple organs – have occurred. in primary vaccines, starting two to five days after vaccination.

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The Centers for Disease Control and Prevention – the US government health protection agency – warns that viscerotropic disease can lead to multi-organ dysfunction syndrome or multi-organ failure and death in nearly 60% of the cases.

Martin Goodier, assistant professor of immunology at the London School of Hygiene and Tropical Medicine, nevertheless noted that severe reactions were rare and that the vaccine remained "extremely effective".

"The yellow fever vaccine is extremely effective for protection against this infection and has been used around the world for many years," he told CNN. "Because of the widespread use of the vaccine, we can say with certainty that such adverse events are rare.The health benefits of vaccination far outweigh any potential risk."

The WHO also told CNN: "While the risk of adverse events is higher among people over 60, the overall risk remains low." The organization nevertheless noted that a "risk-benefit assessment" should be conducted for people over 60, taking into account the risk of contracting the disease.

Jonathan Ball, Professor of Molecular Virology at the University of Nottingham, added: "Vaccinated people are advised to get vaccinated if they travel to tropical and subtropical areas where we know or suspect that yellow fever exists. "

He noted that although the vaccine is "very safe", the serious side effects are more likely to develop in the over 60s and in very young infants. In particular, he cited reports suggesting that the risk of developing a "Viscerotropic Vaccine Associated Disease" increased to about 12 cases per million doses of vaccine used, compared to 3 times per million in the 60s.

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However, he stated that it was "always logical" that people belonging to "at-risk age groups" be vaccinated if the risk of exposure to the virus was very high.

Gore was an oncologist for over 35 years and joined the Royal Marsden in 1978 as a senior officer. He was appointed Medical Director of the Trust in 2006 and served in that role for 10 years until his resignation in January 2016.

He was also Chair of the Advisory Committee on Gene Therapy at the Department of Health between 2006 and 2012, Senior Investigator at the National Institute of Health Research between 2008 and 2011 and appointed Commissioner of the Commission on Human Health. Medicines at the Agency for the Regulation of Medicines and Health Products.

Gore also received an award for overall achievements in 2015 from Prince William, president of the Royal Marsden. Commenting on Gore's contribution at the time, the Prince said, "I found Martin a source of inspiration: his infectious enthusiasm and passion for his work, as well as his obvious compassion and kindness to his patients, their family and friends reinforce my belief that the Royal Marsden is a special place.

"He is one of the pioneers of 20th century cancer care and a friend, colleague and trusted doctor for many."