Moderna: Vaccine should offer protection for at least a year
Pfizer chairman: We're not sure if someone can transmit virus after vaccination
Pfizer chairman Albert Bourla told Dateline host Lester Holt that the pharmaceutical company was "not certain" if the vaccine prevented the coronavirus from being transmitted, saying, "This is something that needs to be examined."
In a prime-time special titled "Race for a Vaccine" set to air Thursday, Holt questioned Bourla and other individuals involved in the development and distribution of the medicine.
In November, Pfizer announced that its vaccine candidate had been shown to be more than 90 percent effective at preventing COVID-19 and has applied for emergency use authorization from the Food and Drug Administration (FDA).
The U.K. became the first country to approve Pfizer's vaccine this week with the first round of immunizations expected to roll out next week.
In a list of interview highlights released before the special, Holt asked Bourla, "Even though I've had the protection, am I still able to transmit it to other people?"
"I think this is something that needs to be examined. We are not certain about that right now with what we know," Bourla responded.
Though Pfizer's vaccine has shown promising results, challenges have surfaced when it comes to distributing and administering it. The vaccine must be delivered and stored in extreme sub-zero temperatures, which has heightened the demand for dry ice.
Once the vaccine is kept at normal refrigeration temperatures, it must be used within four or five days or be discarded. The vaccine is administered in two doses spaced a few weeks apart.
Government health officials have said that if the vaccine is approved, the first round of immunizations could be available for health care workers and high-risk individuals before the end of the year.
Moderna and AstraZeneca have announced their own vaccine candidates to be highly effective at preventing the coronavirus as well with Moderna applying for emergency use authorization from the FDA.