Pfizer, responding to criticism, presses case for COVID-19 booster shots

 

• Pfizer, in a quarterly earnings presentation Wednesday, defended plans to soon seek regulatory clearance for a coronavirus booster shot, offering new details that could point to a waning effect of its shot over time.
• The drugmaker has already butted heads with U.S. regulators about the need for a booster. But the spread of the more transmissible Delta variant and data from Israel showing potentially reduced protection from infection have raised concerns that a third shot may be necessary.
• Presentation slides from Pfizer showed a booster elevates neutralizing antibodies against Delta, though it's unclear whether that will translate to increased protection. Still, Pfizer intends to seek emergency authorization of a booster shot as early as next month, the company said Wednesday.

The pandemic has entered a new phase because of the Delta variant, which first emerged in India and has since become the dominant strain in several countries, including the U.S.

Infections are once again rising across the globe, particularly in areas with low vaccination rates. In the U.S., Delta's spread has already led the Centers for Disease Control and Prevention to change earlier guidance about wearing masks, even for some who have been vaccinated.

Vaccinated people remain largely protected against Delta, as multiple studies have shown a two-dose regimen of Pfizer's vaccine can nearly eliminate the chance of severe illness and death from infections caused by the variant. But Pfizer has long contended a booster is needed to protect against waning immunity, and has advanced plans to test a third dose of its original shot as well as a Delta-specific vaccine.

Pfizer's assertion alarmed the Food and Drug Administration and CDC, which earlier this month issued a public rebuke and insisted that boosters aren't needed "at this time." Recent data from Israel's health ministry showing the shot was just 39% effective in preventing infections, however, appear to bolster Pfizer's case. Biden Administration health officials have reportedly begun to embrace boosters as well, at least for vulnerable groups like the elderly or immunocompromised.

During its quarterly earnings presentation on Wednesday, Pfizer advanced its case. On one slide, Pfizer showed how far neutralizing antibody levels fell against the original coronavirus strain and a different variant, Beta, over time. Levels were "quite low" eight months after the second dose, wrote Evercore ISI analyst Umer Raffat, in a note to investors.

Additionally, a preprint paper released Wednesday indicated the shot's efficacy gradually declined from 96% to 84% six months after vaccination, though it was still 97% protective against severe disease.  

"I remember saying we believed, based on the data, we will need a booster eight to 12 months from second dose," said chairman and CEO Albert Bourla, on a conference call. "We have seen with Delta we might need it a little earlier."

In another slide, Pfizer disclosed a third shot of its current vaccine drove neutralizing antibody levels against Delta more than five-fold higher for people under 55 and over 11 times higher for those older than 65 years of age. Pfizer believes that may lead to better protection than a two-shot regimen, but that hasn't been proven. The threshold for immunity isn't yet known, and there are several other immune defenders — such as B cells and T cells — involved in the body's response to infection.

Pfizer began a Phase 3 study of a third shot this month and could seek emergency clearance of a booster shot in August, the company said Wednesday. Pfizer could start a trial for a shot tailored to the Delta variant next month as well.

The company, separately, reported $7.8 billion in sales from its coronavirus vaccine this quarter and now projects more than $33 billion for the year, which would be a record for a pharmaceutical product.

An oral antiviral that Pfizer's developing for COVID-19 is in late-stage testing as well. If the results are positive, Pfizer could file for an emergency authorization by the end of the year.

https://www.biopharmadive.com/news/pfizer-coronavirus-vaccine-booster-plan-delta/604063/