Big Covid–19 vaccination changes in South Africa — including mixing booster shots
South Africa’s health department has issued a circular that dramatically reduces the intervals between Cominarty vaccines, and allows different vaccines to be mixed for booster shots from 23 February 2021. The waiting period before you are allowed to receive your booster has also been reduced. Those receiving the Pfizer-BioNTech Cominarty two-dose vaccine now only need to wait 21 days before getting their second shot — down from 42 days.
For the booster shot, the waiting period has been reduced from 180 days to 90 days, and you can receive either the Pfizer or Johnson & Johnson vaccine. Similarly, those who received the Johnson & Johnson vaccine will now be able to use Pfizer or Johnson & Johnson for their booster shot.
Speaking to Talk 702 on Monday, health department deputy director-general Nicholas Crisp confirmed the changes. “We are now able to mix the vaccines. It has been done in other parts of the world for some time, and we are now formally introducing it into our schedule,” he said.
Crisp explained that South Africa increased the intervals between the first and second dose of the Comirnaty vaccine in June or July last year we the country started running out of stock.
“We were very cautious and had gone to more-or-less the maximum intervals,” said Crisp. “We’re now going back to what most of the rest of the world is using on what’s regarded as minimum intervals to get a good immune response.” Crisp said that the department is reducing the vaccine intervals for two reasons.
“One is that people get tired and forget about their vaccines if the intervals are too long,” he said. “Secondly, we have plenty of vaccine in stock, so there’s no reason to widen the intervals at the moment.”
Crisp said that early indications are that regular booster shots for Covid–19 may not be necessary, but it all depends on how different new variants are. “We don’t think at this stage that it looks like we will need to re-boost because these vaccines are generating cellular immunity, and that’s got very good memory,” he explained.
“We’ll watch and see what happens, and it seems that as long we’re dealing with the same variants — or very similar variants to what we have at the moment — it may not be necessary to keep boosting.”
Crisp also provided definitions for the terms homologous and heterologous boost that are floating around social media:
- A homologous boost means that you use the same vaccine after an interval to stimulate more immune response on someone who’s already received that vaccine.
- Heterologous means you use a different vaccine to stimulate an immune response from someone who’s already had a vaccine.
Extract from the Department of Health circular on vaccination intervals — February 2022