During the past 50 years, the number of pharmaceutical companies making vaccines has decreased dramatically, and those that still make them have reduced resources to produce new ones, writes Phil Taylor.
This is the view of Paul Offit, head of infectious diseases at the Children's Hospital of Philadelphia in the US, in a commentary published in the journal Health Affairs (May/June issue). Offit notes that the number of firms producing vaccines has dropped from 28 in 1967 to just five in 2004, a contraction that cannot be explained simply by the consolidation in the sector over the intervening years.
"Recent shortages of vaccines, most recently the flu vaccine during the past winter, are not short-term glitches - they reflect long-term problems in the vaccine industry," according to Offit. Since 2001, there have been shortages of vaccines against eight diseases, including tetanus, measles and rubella.
Pharmaceutical companies are gradually abandoning vaccines because the research, development, testing and manufacture of them are expensive, as well as the fact that the market for them is much smaller than that for other drug products.
For example, the vaccine against pneumococcal disease in children has annual US gross sales of about $1 billion, the highest revenue generated by a vaccine. In contrast, markets for cholesterol-lowering agents, hair loss products, potency drugs, or drugs for heart disease or obesity are often $7 billion or more per drug, notes Offit.
Among the four large pharmaceutical companies still making vaccines, vaccines bring in 6 percent or less of their total revenue. "All four companies could stop making vaccines tomorrow without much impact on their bottom lines," he writes.
Meanwhile, on the manufacturing side, vaccines are often more costly to produce than drugs because they are made from live viruses, instead of chemicals. This means that making a vaccine can require hundreds of steps, each subject to stringent sterility guidelines.
He adds that product liability law suits have also sharply raised costs for manufacturers and, unless changes are made, the world is likely to see increasing shortages. A 1986 lawsuit claiming that pertussis vaccine caused paralysis in a child yielded a jury award of $1.1 million - more than half of the entire market for pertussis vaccine at the time, and despite the fact that no scientific evidence backed the claim.
In the US, the government has gone some way to easing the risk assumed by vaccine developers via the Vaccine Injury Compensation Programme, a national fund that compensates families whose children are injured by vaccines. But Offit maintains that flaws in this program limit its effectiveness. Families can choose to opt out of the programme and proceed to a jury trial, the program does not cover all vaccines, and it does not cover effects on an unborn child when the mother is vaccinated.
"Fearful of litigation, no pharmaceutical company is willing to produce a vaccine known to protect newborns from a group B streptococcus infection, a disease that kills 100 US newborns each year, claims Offit.
He recommends that the US Congress take steps to increase vaccination coverage by offering financial incentives to manufacturers and healthcare professionals and urges the correction of weaknesses in the Vaccine Injury Compensation Program to lower the costs of vaccine production. Finally, he proposes more public-private partnerships to improve vaccine development.