From Wednesday you can mix the Pfizer and J&J vaccines on request – at least in theory


  • From Wednesday, you should be able to get a mixture of the J&J and Pfizer vaccines against Covid-19 in South Africa.
  • You just have to be fully vaccinated with the one, then ask for the other as a booster, after either 60 or 90 days, depending on which you got first.
  • Those are the instructions that vaccine sites have received, anyway.
  • In reality you may find it a bit tricky to secure a dose of J&J as a booster, and you may have to shop around a bit.
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By Wednesday, any South African already fully vaccinated against Covid-19 will be able to request a mixer booster vaccine, to potentially benefit from what has become known as the “mix and match” approach.

The door for mixing opens to previous J&J recipients today (21 February), when anyone who received a J&J shot no more recent than Christmas may ask for a dose of Pfizer.

For the far more numerous recipients of the Pfizer vaccine, the window opens on Wednesday. At that point, anyone who received a second dose of Pfizer no more recently than 24 November can ask for their third jab to be of the J&J variety instead.

See also | SA just slashed in half the time it takes to be Pfizer boosted for travel purposes

There are grounds to believe that mixing vaccines for booster shots (technically known as heterologous boosters, as opposed to the homologous boosting by way of another dose of the same vaccine) could be beneficial in terms of the protection it provides – as well as making for easier logistics. But though the safety of mix-and-match has been confirmed, experts say the evidence is not yet sufficient to be sure of a clear benefit.

Previously, South Africa had been strictly stuck to homologous vaccines and boosters.

But on Sunday the director general of the department of health, Sandile Buthelezi, issued a formal circular to health departments and everyone running Covid-19 vaccination sites, announcing the shift to heterologous boosters.

He simultaneously announced a change in the schedule for the Pfizer vaccine, now branded as Comirnaty. Instead of waiting 42 days for a second dose, that can now be administered after 21 days has passed. And the third booster dose of Comirnaty can now be given 90 days after the second, instead of the previous 180.

Recipients of the J&J or Janssen vaccine are eligible for boosters after 60 days.

In all cases, boosters are only for those 18 or older.

The health system will default to homologous boosters, except where the recipient had an adverse reaction when receiving a primary dose. But anyone can mix and match without providing any reason and just by asking, Buthelezi said in the circular.

However, site operators have previously warned that requests for a specific type of vaccine would be difficult to honor for purely logistical reasons. Sites may not have access to both types of vaccine, or may have insufficient demand for one to break out a batch of doses that must then be used within a limited time period, they have warned.

Vaccinators have suggested phoning ahead to a site to check that the preferred type of vaccine is on offer on the day – while also warning that answering phones is not the primary business of a Covid-19 vaccine site.

(Compiled by Phillip de Wet)

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