A third dose of the Pfizer/BioNTech Covid-19 vaccine can "strongly" boost protection against the Delta strain far beyond the protection afforded by the standard two doses, Pfizer says in its Second Quarter 2021 Earnings Teleconference Presentation.
"Emerging real-word data suggests immunity against infection and symptomatic disease may wane".
Essentially, citing data not peer-reviewed yet, Pfizer suggests that the third dose boosted antibody levels against the Delta variant 11-fold more than the second dose.
"Initial safety and immunogenicity data from the study demonstrate that a booster dose given at least 6 months after the second dose has a consistent tolerability profile while eliciting high neutralization titers against the wild type and the Beta (B.1.351) variant, which are 5 to 10 times higher than after two primary doses.
"In addition, newly disclosed data demonstrates that a third dose elicits neutralizing titers against the Delta (B.1.617.2) variant that are more than five times higher in younger people and more than 11 times higher in older people than after two doses. " (Post dose 3 titers versus the Delta variant are >5-fold post dose 2 titers 18-55 y/o & >11-fold post dose 2 titers 65-85 y/o").
Dr. Mikael Dolsten, Chief Scientific Officer and President, Worldwide Research, Development and Medical for Pfizer, called the new insight on a third dose of vaccine "encouraging".
Strong sales of its COVID-19 vaccine and other medicines helped Pfizer nearly double its second-quarter revenue and boost its profit an impressive 59 per cent, beating Wall Street expectations and leading the drug giant to sharply hike its 2021 sales and profit forecasts.
The company had earnings of $5.56 billion, or 98 cents per share, in the second quarter of 2021, compared to $3.49 billion, or 62 cents per share, in the same quarter a year ago.
The New York company also raised its full-year sales forecast for the COVID-19 vaccine it developed with Germany's BioNTech by 29 per cent to $US33.5 billion ($45.7 billion), as nations stock up on doses for the rest of the year.
Pfizer's study of the third dose comes after a study, which hasn't yet been peer-reviewed or published in a medical journal, found the effectiveness of the Pfizer-BioNTech Covid vaccine waned over six months
According to the study, the effectiveness against any symptomatic illness fell from 96.2 percent to 83.7 percent during the 6 month period, falling by about 6 percent every two months.
If the efficacy continues to decrease at the current monthly rate, it can fall below 50 percent within 18 months, requiring a booster shot as Pfizer already has en eye on it.
