Statement: Pfizer position on dosing intervals of the Pfizer-BioNTech COVID-19 Vaccine

[Shiloh]

Source: https://www.pfizer.ca/statement-pfizer-position-dosing-intervals-pfizer-biontech-covid-19-vaccine

Statement: Pfizer position on dosing intervals of the Pfizer-BioNTech COVID-19 Vaccine
23/03/21


We recognize that recommendations on alternative dosing intervals reside with health authorities and may include recommendations due to public health principles. However, as a biopharmaceutical company working in a highly regulated industry, our position is supported by the label and indication agreed upon with Health Canada and informed by data from our Phase 3 study.
Pfizer and BioNTech?s Phase 3 study for the COVID-19 vaccine was designed to evaluate the vaccine?s safety and efficacy following a 2-dose schedule, separated by 21 days. The safety and efficacy of the vaccine has not been evaluated on different dosing schedules as the majority of trial participants received the second dose within the window specified in the study design...
...There are no data from this study to demonstrate that protection after the first dose is sustained after 21 days...

 

[Sonny]

As Canadians begin receiving the coronavirus vaccines, the government is advising recipients of the Pfizer vaccine that they will have to wait four months between their first and second dose.

Now, the National Advisory Committee on Immunization (NACI) has admitted that the reason that Canadians are expected to wait four months between doses is because of the government's failure to acquire an adequate amount of vaccines for Canadians.

As Rempel noted, the interval was chosen purely on the basis of delivery schedule and had no grounding in scientific data. Rempel was left speechless by the revelation, saying only that she was "shocked."

Rempel contrasted the Canadian government's failure to acquire vaccines to the success seen in the United States, where all Americans will be able to receive both doses of the vaccine by May.

https://thepostmillennial.com/watch...to-trudeau-liberals-failure-to-secure-doses-2

 

[sharon sanders]

bump this

 

[JJackson]

Canada pre-ordered enough vaccine for 4 shots per head so if there is a problem it is either because the manufactures have not been able to meet there commitment, due to manufacturing shortfalls, hording in the manufacturing countries or there is a distribution problem in Canada, I have not investigated which.
https://www.statnews.com/pharmalot/2...ne-covaxi-who/
https://www.theguardian.com/world/20...red-per-person

The manufactures, like Pfizer, are correctly stating that they can not say anything definitive about efficacy except that based on the phase 3 trial data on which their EUAs were issued. However subsequent data, from countries that have extended the gap after first dose, clearly show that antibody levels significantly increase for months. The logic that dictates all prime/boost vaccine technologies argues that the maximum effect of the second shot would be when the levels from the first shot are highest so waiting should actually give a better response to the boost.
Why then would you not set the second shot to a two or three month gap in the first place? Firstly, at the trial design stage, nobody expected the first shot to give enough protection to meet the trial efficacy end point on its own but it has done so. Secondly we needed to get results quickly so getting the second shot at the front end of the possible window was desirable. A third problem is if there is only partial protection, and you get infected between the first and second dose, and can generate a high enough viral titter to infect someone else it will be more likely to be a vaccine escape variant. None of the vaccines claim to stop infection, only severe illness, so this may happen after both doses but the higher your antibody count, and B and T cells, the less chance that you will reach a high enough viral titter to be much of a risk to others. As time passes all these counts will decline and your level of immunity will decline with them the booster shot makes sure they are at very high levels to begin with so will have further to fall giving longer lived protection.