Many biopharma companies have been talking up the potential of authorized COVID-19 vaccines by year-end. But experts caution that a rushed timeline could be counterproductive for adoption.
“There are many fears about vaccines already, and consumers are likely to be cautious about a newly approved vaccine rushed through development by government and pharmaceutical companies,” SVB Leerink analyst Geoffrey Porges wrote in a Thursday note to clients after an infectious disease specialist and a Merck & Co. senior executive spoke at an SVB Leerink event.
To combat those fears and “build confidence,” open communication with the general public about vaccine research needs to start now, the experts stressed.
“Transparent and science-driven communication with the general public about any vaccine (particularly for COVID)” will be key “to minimize consumer concerns that could limit vaccine adoption,” Porges summarized the experts as saying, adding that “it is crucial ... to set expectations appropriately and allay any concerns.”
Already, only 14% of investors SVB Leerink surveyed said they would recommend a COVID-19 vaccine to family and friends based on an emergency use authorization by year-end, which, as Porges noted, would only have short-term safety data available. In contrast, 43% would do so if six-month safety follow-up data from a phase 3 study are available, as guided by the FDA.
Several drugmakers have recently shared encouraging early clinical data from their vaccine candidates, but careful interpretation of the results is necessary to manage optimism, the experts argued.
Moderna and the Pfizer-BioNTech team each recently rolled out early immunogenicity data for their respective mRNA vaccine candidates. Both claim neutralizing antibody levels from the immunization that exceeded the levels seen in recovered COVID-19 patients. But the two experts—as have many other scientists—cautioned about calling the responses “functional,” noting it’s unclear exactly what kind of antibodies are needed to confer clinical protection.
In addition, the fact that all phase 1 patients on the high dose of Moderna’s mRNA-1273 experienced systemic side effects including fatigue, fever and headache got one expert a little worried. Although neither of the experts considered the observed side effects deal-breaking, they do expect to hear more safety complaints—and possibly new signals—in the late-stage trial, according to Porges.
For example, one analyst noted that the FDA is keeping a close eye on the theoretical risk of enhanced respiratory disease. This phenomenon was first reported in flaviviruses, in which certain vaccine-induced immunity could exacerbate viral infectivity due to what’s known as antibody dependent enhancement.
In new guidance for the development and licensure of COVID-19 vaccines, the FDA is recommending safety follow-up for at least six months and suggests long-term monitoring after approval may be warranted.
The math is simple. Moderna has said it aims to kick off the phase 3 efficacy study July 27. Pfizer-BioNTech is planning phase 2b/3 “later this month.” Another leading player, AstraZeneca, rolled its University of Oxford-partnered AZD1222 into the phase 2 portion of a phase 2/3 trial in late May. That means they won’t have six-month safety data from phase 3 trials by the end of the year.
Nevertheless, an emergency authorization might come earlier than expected. Fears are already mounting that the Trump administration will pressure drug regulators to approve a COVID-19 vaccine before it’s fully vetted in clinical trials, especially as the president himself is pushing for the economy to reopen. When asked about the FDA approval timeline, half of investors SVB Leerink surveyed said they believe the FDA may take some shortcuts in the review process.
But the two experts emphasized that “it is crucial to communicate science to consumers without political influences.” That, in turn, means a proper FDA authorization that’s based on transparent, full safety and efficacy results is more likely to happen in 2021 rather than 2020.