A Lyme vaccine developed by pharmaceutical companies Pfizer and Valneva has completed the human trials necessary to apply for approval from the U.S. Food and Drug Administration.
Here are answers to three questions about the vaccine:
Where does the Lyme vaccine stand?
After a multi-year clinical trial, the pharmaceutical companies have completed the necessary studies to submit the Lyme vaccine to the FDA. The clinical trial administered either four doses of the vaccine or four doses of a placebo to more than 9,000 patients at sites across the U.S. and Europe, including a number of study participants in Maine. The clinical trial found that the vaccine was generally well tolerated by the patients who received it and caused no safety concerns.
How effective is it?
In the clinical trial, the vaccine reduced Lyme infections by 73.2 to 74.8 percent. However, the companies saw fewer total cases of Lyme disease during the trial than they expected, which meant their efficacy rate measurement could not be as statistically precise as the goal they had set. A spokesperson for Pfizer said this low case number could happen for several reasons, such as total incidents of Lyme infection being lower during the clinical trial period compared with prior years.
“While we acknowledge the statistical limitations driven by lower case accrual, regulators evaluate vaccines based on a benefit-risk framework, and in this case, we see robust efficacy point estimates, a favorable safety profile, and a well understood mechanism of action. Lyme disease presents unique challenges for clinical trials due to exposure variability, and we believe the data supports a meaningful public health benefit,” the Pfizer spokesperson wrote to The Maine Monitor.
When could it be available to patients?
When the companies completed their clinical trials, initial reports stated that the vaccine could be available as soon as next year. However, because the trial did not meet its precision goal, experts predict that the process of preparing to apply to the FDA and receiving the agency’s approval may take longer.
The rollout process is also complicated by uncertainty in the U.S. Centers for Disease Control and Prevention’s independent vaccine recommendation committee. Typically, the committee’s medical professionals would provide guidance on how providers should administer the vaccine to patients and potentially lead to mandated insurance coverage for immunization. But last year, Robert F. Kennedy Jr., the secretary of the U.S. Department of Health and Human Services and a known anti-vaccine activist, replaced every member of the committee without undergoing a full vetting process for new members.
Ongoing litigation surrounding these appointments have prevented the advisory committee from making recommendations about new vaccines.
Pfizer has not committed to any timeline for FDA submission nor eventual rollout.
“We will share updates on regulatory developments when they are available,” the Pfizer spokesperson wrote, adding that the company will “continue to engage with the FDA, CDC, and other relevant public health authorities and remain ready to follow the guidance that ultimately emerges.”
