As Tick-Borne Disease Spreads, Do We Need More Vaccines? - Forbes

Playing in the bracken in Norfolk: a harbouring ground for ticks?

Universal Images Group via Getty Images

As if they didn't have enough to worry about already, Brits found another thing to worry about at the start of the half term holiday with the news that brain illness spread by ticks has reached the U.K.

A small number of ticks had been found to be infected in Thetford Forest, Norfolk and on the Hampshire-Dorset border.

While Public Health England said the risk to humans was “low,” tick-borne encephalitis (TBE) is a serious illness. It causes infection of the central nervous system, including the brain and spinal cord, which can lead to complications such as meningitis.

The TBE virus (TBEV) is found in infected ticks in parts of Asia, Eastern Europe and Scandinavia. Some 10,000-12,000 clinical cases of TBE are reported worldwide each year, but actual cases are likely to be higher.

The good news is that vaccination is an effective prophylaxis against TBE. Nor have vaccinations been associated with serious adverse reactions, according to the WHO, particularly Pfizer’s FSME-Immun vaccination, widely used outside Russia. This has been found to provide immunity to TBE antibodies for at least 10 years.

While Pfizer declined to divulge its share of the global TBE vaccine market, a spokeswoman said, “FSME-IMMUN or TicoVac® Tick-Borne Encephalitis Vaccine (whole virus inactivated) is the only vaccine available in the U.K. that provides immunity against all circulating TBEV subtypes infecting children and adults.”

Encephalitis Virus or Lyme Disease Infected Tick Arachnid Insect

Getty

“In the U.K., TicoVac Junior® and Ticovac® are indicated for the active immunization of persons of 1-15 years of age and 16 years of age and older respectively, against tick-borne encephalitis (TBE) and is to be given on the basis of official recommendations.” She suggested that vaccinations should be given in the winter months to develop immunity on time before the tick season starts. 

Across the southern half of Sweden, where around 10-30% ticks are known to carry infection, there has been pressure on the government to pay for TBE vaccinations. Each shot of FMSE-Immun costs around 400 SEK ($42); new patients require three injections over the first year with a booster after five years. Worried Brits can also vaccinate themselves at private travel clinics for an average price of £60 - £75.

Earlier this summer, I queued up with my daughter and son-in-law for TBE vaccination boosters at a touring vac clinic in the Stockholm archipelago, an area inhabited by lots of ticks. My new son-in-law took it with the same air of acceptance as he does other aspects of the Swedish holiday experience like saunas, schnapps and drinking songs.

The writer waiting at a touring vaccination clinic in the Stockholm archipelago

Heather Farmbrough

TBE is not the only serious tick-borne disease; Lyme disease is the most common tick-borne disease in North America and it’s been on the increase over the last decade. Since its progression depends on environmental factors, researchers have suggested that increases in daily temperatures, a manifestation of climate change, might be contributing to a rise in the number of ticks.

If temperatures rises 2 degrees Celsius (3.6 degrees Fahrenheit) by mid-century, based on the U.S. National Climate Assessment predictions for 2036-2065, the number of cases of Lyme disease in the U.S. will increase about 21% by 2050, generating 8.6 more cases of Lyme disease per 100,000 people annually.

Lyme’s disease, if untreated, can eventually cause serious neurological problems and meningitis. A three-week course of the antibiotic doxycycline is regarded as an effective early treatment for bites from Lyme-infected ticks.

In the late 1990s, SmithKline Beecham developed a vaccine called LYMErix, said to be effective in up to 90% of those who had it. By the end of 2001, 1.4 million doses had been administered. LYMErix was not popular, because it was relatively expensive, new patients needed three does, and it only protected against one strain of Lyme disease, but it worked.

Shortly afterwards, however, the journal Lancet published a now-retracted study that claimed the measles, mumps, and rubella vaccine (MMR) was linked to autism. Concerns grew that LYMErix could induce an human autoimmune reaction—based on studies that found it contributed to arthritis in hamsters.

Over the last few years, clinical trials have been underway for a new vaccine against Lyme Disease, manufactured by Valneva, a French biotech company.

https://ift.tt/2WxNDOK