Disease breakdown of the global vaccines market (2001). Source: Datamonitor

Poor sales have prompted GlaxoSmithKline (GSK) to withdraw its Lyme disease vaccine, LYMErix, from the United States market. Lawsuits relating to adverse effects of the vaccine have been filed since its introduction, but the US Food and Drug Administration (FDA) found no proof that LYMErix is dangerous. It appears that lack of demand, not safety concerns, is the reason for the withdrawal.

Importantly, the move shows that even though the global vaccine market is expected to increase by 25% within the next five years—from a value of $4,800 million to $6,400 million—vaccine manufacturers are not immune to financial forces, which signals a troubled future for new vaccines against rare diseases such as West Nile virus (WNV) and Ebola if they complete development.

LYMErix was approved by the FDA at the end of 1998, and earned $40 million in peak sales during its first year on the market. In 1999, 16,273 cases of Lyme disease, concentrated mostly in the northeastern states, were reported to the US Centers for Disease Control and Prevention (CDC). However, GSK withdrew LYMErix following predictions that less than 10,000 people would be vaccinated in 2002.

According to a recent report by industry analyst group Datamonitor, LYMErix represented only 0.4% of the global vaccine market sales in 2000. “Companies need to assess which of the markets will maximize their revenue,” says analyst Amber Gibson, author of the report. “Companies should also establish strong relationships with governments and ensure that the vaccines they are developing are in line with government priorities,” she adds.

A cost-effectiveness analysis of the Lyme disease vaccine by the CDC indicates that the use of LYMErix vaccine is justified only in areas in which the incidence of Lyme disease is high. They found that the mean net savings of vaccination per case averted is $3,377 if the probability of contracting Lyme disease is estimated at 0.03. However, the probability of contracting Lyme disease is, in all but a few areas, less than 0.005.

Vaccine expert Stanley Plotkin, who presently consults for Aventis Pasteur, calls the withdrawal of LYMErix “regrettable.” He says, “This vaccine was developed because of a perceived demand by the public for protection against a common infection,” but he remembers that the CDC gave the vaccine at best a “lukewarm” recommendation. They proposed that it “should be considered” only for persons aged 15–70 years with frequent or prolonged exposure to tick-infested habitats or travelers to these areas. Indeed, the 1999 cost-effectiveness analysis by the CDC remark-ed, “Ours is not the only study to suggest that the vaccine not be used universally,” and cited an Institute of Medicine report that gives a Lyme disease vaccine the lowest ranking in terms of priorities for vaccine development.

Plotkin believes that the vaccine's withdrawal means there never will be a Lyme disease vaccine and that other vaccines against diseases such as WNV might never reach the market. “No company is going to spend hundreds of millions to develop a vaccine that will not be recommended and therefore will not sell,” he points out.

But these new vaccines are making their way through the academic research pipeline nonetheless, including a combined vaccine against WNV and dengue virus (Proc. Natl. Acad. Sci. USA 99, 3036; 2002). The Datamonitor report indicates that WNV vaccines are unlikely to be strong candidates for widespread immunization programs. “However, the susceptibility of infants and the over-50s to the more severe manifestations of this disease mean that in endemic regions vaccines could be considered for both childhood and elderly immunization programs,” they point out.

Gibson suggests that development of novel technologies in vaccine discovery, formulation and delivery will be critical for attaining market share. When assessing the value of a vaccine, various factors, such as the severity of the disease and the mortality rate, must be considered, but so must the cost of treating the disease. “Basically, if the cost of immunizing every individual is lower than the cost of treating the number who get the disease, then you can justify its use,” she says.