# Mix-and-match vaccination: how isn't this as terrible an idea as it sounds? **URL:** \ **Category:** The Quarantine Zone\ **Tags:** covid-quarantine\ **Created:** [January 2, 2021, 8:33am UTC](https://boards.straightdope.com/t/mix-and-match-vaccination-how-isnt-this-as-terrible-an-idea-as-it-sounds/929509 "2021-01-02T08:33:12Z")\ **Posts on this page:** 5\ **Page:** 1
**Author:** ![Half\_Man\_Half\_Wit](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/half_man_half_wit/32/21766_2.png) [@Half\_Man\_Half\_Wit](https://boards.straightdope.com/u/Half_Man_Half_Wit)\ **Post date:** [January 2, 2021, 8:33am UTC](https://boards.straightdope.com/t/mix-and-match-vaccination-how-isnt-this-as-terrible-an-idea-as-it-sounds/929509/1 "2021-01-02T08:33:13Z")
So apparently, officials in Great Britain have [updated their vaccination guidance](https://www.nytimes.com/2021/01/01/health/coronavirus-vaccines-britain.html): > [@](#): > > If a second dose of the vaccine a patient originally received isn’t available, or if the manufacturer of the first shot isn’t known, another vaccine may be substituted, health officials said. Now, obviously, this sort of thing hasn’t been tested, so there’s no data to support that sort of strategy. But is there even any sort of reason to think that it would be effective? I suppose that two vaccines that are similar enough in functionality might be expected to work well in tandem, but what about, say, an mRNA vs vector virus vaccine or inactivated virus vaccine? Is the idea that you just need to get enough of the antigen into the system? It seems like that can’t be quite all there’s to it—I mean, I know that the currently administered vaccines have a difference in time interval between the two shots, presumably affecting efficacy—so do you just average the delay and hope for the best? So, is this likely to be an effective and safe treatment? Or is this just the grasping at straws it seems? ---
**Author:** ![Half\_Man\_Half\_Wit](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/half_man_half_wit/32/21766_2.png) [@Half\_Man\_Half\_Wit](https://boards.straightdope.com/u/Half_Man_Half_Wit)\ **Post date:** [January 3, 2021, 6:38pm UTC](https://boards.straightdope.com/t/mix-and-match-vaccination-how-isnt-this-as-terrible-an-idea-as-it-sounds/929509/2 "2021-01-03T18:38:31Z")
OK, giving this one bump. Does anybody have any information at all? ---
**Author:** ![FigNorton](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/fignorton/32/5619_2.png) [@FigNorton](https://boards.straightdope.com/u/FigNorton)\ **Post date:** [January 3, 2021, 6:56pm UTC](https://boards.straightdope.com/t/mix-and-match-vaccination-how-isnt-this-as-terrible-an-idea-as-it-sounds/929509/3 "2021-01-03T18:56:42Z")
> **[Coronavirus: BMJ urges NYT to correct vaccine 'mixing' article](https://www.bbc.com/news/uk-55519042)** > > The medical journal's editor says UK guidelines don't recommend giving different coronavirus jabs. ---
**Author:** ![gdave](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/gdave/32/3683_2.png) [@gdave](https://boards.straightdope.com/u/gdave)\ **Post date:** [January 3, 2021, 7:06pm UTC](https://boards.straightdope.com/t/mix-and-match-vaccination-how-isnt-this-as-terrible-an-idea-as-it-sounds/929509/4 "2021-01-03T19:06:24Z")
As @FigNorton’s cite indicates, there was _never_ a recommendation that a different vaccine may be substituted. In fact, the clear guidance is that different vaccines _shouldn’t_ be mixed. But, _if_ for whatever (hopefully very rare) reason the first dose can’t be identified when it’s time to get the second dose, it’s better to take a guess and get _something_ than get nothing. At worst, it’s a 50/50 chance to get the right second dose. And there is some evidence that even a single dose of the Pfizer vaccine gives some protection. So either way, something is better than nothing. ---
**Author:** ![Half\_Man\_Half\_Wit](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/half_man_half_wit/32/21766_2.png) [@Half\_Man\_Half\_Wit](https://boards.straightdope.com/u/Half_Man_Half_Wit)\ **Post date:** [January 3, 2021, 8:00pm UTC](https://boards.straightdope.com/t/mix-and-match-vaccination-how-isnt-this-as-terrible-an-idea-as-it-sounds/929509/5 "2021-01-03T20:00:05Z")
Alright! Thanks for that, it’s a relief to hear.