This morning, Pfizer issued a press statement to share that their COVID-19 vaccine (developed in partnership with BioNTech) provided protection to more than 90% of subjects who received it in trials. This is certainly welcome news as more than ten million Americans have been infected.
The DJIA closed up about 3%, shares in Carnival Cruise lines rose almost 40% today, and there is clearly cause for optimism. But much work and many unknowns remain. The selloff in Clorox (shares down more than 10%) may have been premature.
Pfizer anticipates that sufficient safety data will be available by about Thanksgiving to support an application for Emergency Use in the United States. While it’s not clear how long the FDA would take to review an application, it’s a safe assumption that Pfizer has been keeping the FDA scientists posted with each step of progress. Assuming approval is granted, Pfizer estimates that they can produce 50 million doses (enough for 25 million patients to receive the two-dose series) this year and more than 1 billion doses in 2021.
The technology used to produce the Pfizer vaccine (using mRNA) is also used in the production of Moderna’s vaccine, so the Pfizer results suggest that Moderna may be successful as well. And while other vaccines in development do not use the mRNA technology, they target the same viral protein. Moderna expects to report effectiveness and safety data for its vaccine around the same time Pfizer safety data should be available. And other developers (using non-mRNA techniques) should follow with data presentations in the next few months.
Assuming the Pfizer (and other) vaccines are safe, the most significant remaining question is how long vaccine-induced immunity will last. With influenza, you have imperfect protection for several months. With the measles vaccine, protection is typically life-long. Let’s hope COVID-19 vaccines are more like the latter.