The story of Chandler Webb is a tragic one. He was a healthy 19-year-old boy who late in October developed a headache and vomiting. His symptoms progressed quickly, and a week later he was admitted to the hospital, where he continued to progress despite treatment.

Chandler was diagnosed with encephalitis – inflammation and swelling of the brain. This is a serious condition, potentially fatal. I have treated many cases of encephalitis, and they are always challenging. Chandler’s doctors are not free to disclose the details of the case, but from his Mother’s descriptions and the news reports it seems like a typical case.

His doctors performed extensive workup, which would include blood tests, lumbar punctures for spinal fluid analysis, serial imaging with CT scan and MRI scan, and eventually a brain biopsy. The purpose of this workup is to find a treatable cause of the encephalitis, which might be an infection, and autoimmune disorder, or toxicity, or cancer. Apparently this extensive workup was negative for a specific cause.

Without a smoking gun, his doctors would have treated him with broad-spectrum antibiotics to cover any bacterial infection, until this was adequately ruled out. Most viral infections are not treatable, but antivirals were probably given early on until those specific viruses were ruled out. Steroids were also likely given, especially after initial workup ruled out a fulminant infection. Steroids reduce swelling and inflammation, but can worsen certain infections by suppressing the immune system.

In Chandler’s case, the workup did not reveal anything specifically treatable. He rapidly progressed until the pressure inside his had pressed on his brainstem, causing him to become comatose. A month later, his prognosis grim, his family agreed to remove life support and Chandler died.

While tragic, this story in itself is not news. What makes this story different is that Chandler’s mother believes his encephalitis was caused by the flu-vaccine he received the day before his symptoms started. Antivaccinationists, of course, have uncritically latched onto this claim for propaganda purposes.

The incidence of encephalitis is about 1 in 200,000 people per year. For reasons still unknown, there is a higher incidence in England, of about 4-5 per 100,000 per year. Death from encephalitis in the US occurs in about 4-5 people per 1 million per year.

The vast majority of encephalitis cases are caused by viral infections. Sometimes we can identify the virus, such as the Herpes simplex virus, West Nile virus, Japanese encephalitis, and others. In many cases a specific virus cannot be identified. Infection with an unknown virus becomes the diagnosis of exclusion when all other specific causes are ruled out.

The incidence of serious side effects from vaccines is about 1 per 1 million doses given. This is far less than the serious outcomes prevented by vaccines every year, making the risk benefit ratio for vaccines one of the best for any medical intervention. Of course, nothing is risk free, and it is openly acknowledged by medical professionals and vaccine defenders that there are risks and rare cases of serious adverse events.

However, it is difficult to determine in a specific case whether or not a vaccine caused the adverse outcome. People, even young healthy people, get viral encephalitis seemingly out of nowhere, because they were exposed to the wrong virus or the virus happened to get access to the central nervous system. It’s just bad luck. Some of those people, by chance alone, will have recently had a vaccine.

One way to establish a possible cause and effect, rather than just chance association, is to look at the risk of developing encephalitis in relation to the timing of vaccines. Several studies have failed to find any association between vaccination and risk of developing encephalitis . There are case reports of encephalitis following vaccines, including the flu vaccine, but I could find no studies establishing an increased risk of encephalitis following vaccination.

Despite this lack of evidence, it is plausible that a vaccine could trigger an autoimmune response, perhaps in rare predisposed individuals or those who also happen to have a current infection with a virus capable of causing encephalitis. Any individual case of encephalitis following a vaccine could have been caused by the vaccine. There is no way to prove or disprove this possibility, unless another specific cause of the encephalitis is found.

What we can say, based upon the current evidence, is while a vaccine-caused encephalitis is possible, if it does occur it is extremely rare. Reported cases of encephalitis following vaccines are rare, and at least some of those must be a non-causal coincidence. It is possible that they all are coincidence, and vaccines never cause encephalitis, But in the worst case if there are excess cases of encephalitis caused by vaccines it is on the order of much less than one case per million vaccines. You are much more likely to get encephalitis from the flu, form measles, or from some other infection prevented by vaccines, than from the vaccine itself.

None of the popular news reporting of this case put the tragic story into this proper scientific perspective. Some science bloggers did, of course. While antivaccinationists exploited the case to fear monger about vaccines.

The news reporting was generally irresponsible, essentially basing the story on the suspicions of a grieving mother. Meanwhile, Chandler’s doctors are prohibited from weighing in because of confidentiality. Unfortunately, Chandler’s mother, convinced of the vaccine hypothesis, is refusing an autopsy and so we are likely missing our last opportunity to establish a specific cause for Chandler’s encephalitis.


Steven Novella, M.D. is the JREF's Senior Fellow and Director of the JREF’s Science-Based Medicine project.