COVID Boost Response by Delaying Second Dose -- Pfizer vaccine in elderly

[Tom.G]

This applies to the Pfizer vaccine. Article dated May 13, 2021.

https://www.nature.com/articles/d41586-021-01299-y

Older people who waited 11–12 weeks for their second jab had higher peak antibody levels than did those who waited only 3 weeks. ...could boost antibody responses after the second inoculation more than threefold in those older than 80. (bold added)

Cheers,
Tom

 

[Ygggdrasil]

The Pfizer vaccine has already been observed to be very effective in older individuals (the original Phase III trial observed a 100% vaccine efficiency for those >75 (though this was based on a fairly low # of people) and real world data from Israel indicated a 95% protection for those > age 70. So, delaying the second dose probably would not increase protection very much (hard to do much better than 95% protection) and could actually lead to more disease if the protection before the second dose in weeks 3-11 is not effective as the protection from getting a second dose at week 3.

However, this data could be useful in designing vaccines going forward. For example, future vaccines might be able to use a lower dose of vaccine (which would hopefully have lower side effects) with greater spacing to achieve similar levels of protection.