Lyme Disease Vaccine – LymeRix
A Lyme disease vaccine, LYMErix was introduced to the US market in 1998 but withdrawn, following complaints and poor uptake, in 2002. The manufacturers of the vaccine for Lyme disease, SmithKline Beecham (now GlaxoSmithSkline), used OspA as the target for antibody production in an attempt to forestall the transmission of Borrelia bacteria to the inoculated host mammal once bitten by a tick. The intention was for antibodies in the hosts’ blood to act on the bacteria in the gut of the tick as the tick takes its first blood meal from the host. By targeting the outer surface protein used by the Lyme disease bacteria to adhere to the ticks’ gut wall and avoid elimination, the vaccinated host mammal would, hopefully, prevent infection of the host mammal and possibly clear the tick itself of Borrelia infection.
Efficacy of LymeRix
The LYMErix vaccine was only used for patients over fifteen years of age and was contraindicated for those taking medications such as prednisone, hydrocortisone, methotrexate, and belimumab, amongst many others. The Lyme disease vaccine was shown to prevent Lyme disease in around 80% of those exposed to the condition and research trials were underway to determine how often booster shots may be needed. There was also a monitoring programme for vaccinated children to observe the possible risks and benefits in one of the groups most prone to tick bites. Unfortunately, adverse effects from the Lyme disease vaccine were observed in more than 10% of patients with pain at the injection site (24.1%) the most common issue. Others who received the vaccine experienced arthralgia (7%), headache (5.6%), myalgia (3.2%), erythema (a rash [1.8%]), flu-like illness (2%), and/or fever (2%). These symptoms were usually reported in the first two days after vaccination and generally dissipated after three days.
LymeRix and False-Positive Lyme Disease Tests
One other concern with the Lyme disease vaccine was the possibility of it giving a false-positive result on an ELISA test for Lyme disease. It was also unknown how long the vaccine conferred protection to Borrelia burgdorferi sensu stricto, and there were concerns that the heterogeneity (differences between populations) of Borrelia burgdorferi sensu stricto might affect the success of the vaccine across all North American Lyme disease-causing bacteria. Indeed, this high level of heterogeneity in the Borrelia population was the reason that OspA was chosen as the target for antibody production in the vaccine as it appears to be the most consistently expressed outer surface protein across all bacteria.
The Borrelia afzelii strain predominant in Europe however, along with Borrelia garinii, would be less well served by such a vaccine due to differing levels of OspA expression. The timing of the Lyme disease vaccine also requires some planning as guidance given with LYMErix was to administer three separate doses, with the second dose a month after the first and immediately preceding the tick’s nymphal feeding season in April. The third dose at twelve months would then precede the subsequent tick season.
The Demise of LymeRix
Things started to look bleak for LYMErix’s prospects when doubts were raised over the safety of the vaccine in regards to a potential sensitivity in some patients to the target protein, OspA. Some researchers were concerned that a small subgroup of patients receiving the Lyme disease vaccine were developing arthritis and other symptoms that mirrored those symptoms reported in cases of chronic Lyme disease. Some patients attempted to gain compensation from the LYMErix manufacturers by filing class action lawsuits and the high profile court cases tarnished the Lyme disease vaccine’s reputation. Subsequent research appears to have disproved the link between the Lyme disease vaccine and the purported symptoms, but the damage was already done and the poor sales of the vaccine were blamed for its removal from the market.
Continue Reading –> New Lyme Vaccine Needed