In each of the EUAs, the FDA has been careful to avoid any claim that the vaccines provide protection against infection or transmission of the virus. Similarly, the Centers for Disease Control (CDC), the World Health Organization (WHO), and the National Institutes of Health (NIH) have each publicly stated that the vaccines have NOT been shown to prevent infection or transmission.
All of their regulatory documents and commentary addressing the issue state clearly that there is no evidence that the vaccines affect either infection with or transmission of the virus, nor do they prevent symptoms of Covid-19 from appearing.
The US Government Position
The FDA’s Briefing Document analyzing clinical trial data for the Pfizer vaccine, released the day before the FDA’s issuance of an EUA for that vaccine, noted (on page 47):
Data are limited to assess the effect of the vaccine against asymptomatic infection
Data are limited to assess the effect of the vaccine against transmission of SARS-CoV-2 [virus] from individuals who are infected despite vaccination.”
The FDA Briefing Document on the Moderna vaccine stated the same fact, while also describing plans for a future clinical trial to measure infection prevention, but that will not be completed until December 31, 2023 (p.47). The FDA’s review of the Janssen vaccine noted the same “limited” data…
to assess the effect of the vaccine in preventing asymptomatic infection… and definitive conclusions cannot be drawn at this time.”
“Limited data” means there is in fact no evidence to support those conclusions.
The CDC Advisory Committee that recommended emergency use of the Moderna vaccine noted:
“the level of certainty for the benefits of the Moderna COVID-19 vaccine was… type 4 (very low certainty) for the estimates of prevention of asymptomatic SARS-CoV-2 infection and all-cause death.”
The CDC guidance to Covid vaccine administrators (January 2, 2021) asks:
Can a person who has received a Covid-19 vaccine still spread COVID-19? At this time, we do not know if COVID-19 vaccination will have any effect on preventing transmission.”
The World Health Organization (WHO) on January 26, 2021 similarly admitted:
We do not know whether the vaccines will prevent infection and protect against onward transmission.”
What do you think, max? The study on efficacy won't be done until 2023,