Thomas Fuller | Nurfoto | fake images
Pfizer on Monday said it will seek regulatory approval for a Lyme disease vaccine candidate even though the shot failed in a late-stage trial.
Pfizer said the vaccine fell short of the trial's statistical goal because not enough people in the study got Lyme disease to trust the results. Still, the company said the shot reduced the infection rate by more than 70% in people who received the vaccine compared to the placebo, an efficacy the company believes is strong enough to take to regulators.
“The efficacy shown in the VALOR study of more than 70% is very encouraging and creates confidence in the vaccine's potential to protect against this potentially debilitating disease,” Pfizer chief vaccine officer Annaliesa Anderson said in a statement.
A vaccine for Lyme disease is not expected to become a bestseller for Pfizer, and the company's partner, Valneva, estimates peak annual sales at $1 billion. Pfizer expects overall revenue of around $60 billion this year, and its Covid-19 vaccine accounts for more than $5 billion of that forecast.
But Pfizer had seen the Lyme vaccine results as one of its main catalysts this year, and represented an opportunity to introduce the only human vaccine against Lyme disease.
Moving forward with a vaccine that technically failed to pass a clinical trial under an administration that has preached stricter scrutiny of vaccines may prove risky for Pfizer and could serve as a litmus test for U.S. vaccine policy.
Lyme disease is a disease caused by bacteria that is most commonly transmitted to humans by ticks. It can cause arthritis, muscle weakness, and pain. About half a million Americans are diagnosed or treated for Lyme disease each year, according to estimates from the Centers for Disease Control and Prevention.
Despite the prevalence of the disease, especially in the Northeast, there is no vaccine available for humans. A company that would later become GSK introduced a vaccine called LYMErix in 1998, but withdrew it only a few years later after public concerns about safety sank demand. That experience hampered the development of Lyme vaccines for humans, although several companies now make them for dogs.
Pfizer and Valneva have faced their own setbacks. In 2023, the companies eliminated about half of the Phase 3 trial participants due to quality concerns with third-party clinical trial site operator Care Access. The trial had initially enrolled about 18,000 people and ended with about 9,400 after cuts.
The companies' vaccine targets protein A on the outer surface of the bacteria that causes Lyme disease. A vaccinated person creates antibodies that are transmitted to a tick and prevent the bacteria from transferring from the tick to humans. The series includes three injections during the first year and then a booster dose the following year.
The companies said they did not see any safety concerns in the trial.
