The South African Health Products Regulatory Authority (SAHPRA) has approved the third Pfizer Covid vaccine booster dose for people over the age of 18.
SAHPRA initially approved the use of the Pfizer Comirnaty Covid-19 vaccine on 16 March 2021 and received an application to amend the dosing schedule for the vaccine on 21 November.
Following evaluation of the data submitted, SAHPRA has now approved the following:
- A third dose of the Comirnaty Covid-19 vaccine in individuals aged 18 years and older, to be administered at least 6 months after the second dose.
- A third dose of the Comirnaty Covid-19 vaccine in individuals aged 12 years and older, who are severely immunocompromised, to be administered at least 28 days after the second dose.
For the time being, mixing Covid vaccines is not part of the recognised courses for vaccinating against Covid-19.
“The data provided only dealt with the situation of homologous boosting, where the third dose is of the same vaccine as the initial course – in this case, two doses,” SAHPRA said.
“SAHPRA is aware of the keen interest in the efficacy and safety of heterologous boosting regiments – so-called ‘mix and match’ approaches – and invites submissions of supportive data in this regard,” it said.
Pfizer vs Omicron
Omicron’s ability to evade vaccine and infection-induced immunity is “robust but not complete,” said the research head of a laboratory at the Africa Health Research Institute in South Africa.
In the first reported experiments gauging the effectiveness of Covid-19 vaccines against the worrisome new strain, researchers at the institute found that the variant could partially evade the vaccine produced by Pfizer and BioNTech.
Still, its evasion wasn’t complete and a booster shot could provide additional protection, Alex Sigal said in an online presentation on Tuesday.
Since South Africa announced the discovery of Omicron on 25 November, around 450 researchers globally have worked to isolate the highly mutated variant from patient specimens, grow it in the lab, verify its genomic sequence, and establish methods to test it in blood-plasma samples, according to the World Health Organisation.
Omicron’s rapid spread in South Africa has raised concern that the immune protection generated by vaccination or a previous bout of Covid-19 is insufficient to stop reinfections or stem a fresh wave of cases and hospitalisations. The WHO has warned Omicron could fuel surges with “severe consequences” amid signs that it makes the coronavirus more transmissible.
The work in Sigal’s lab involved testing blood plasma from people who were vaccinated against Covid-19 to gauge the concentration of antibodies needed to neutralize, or block, the virus.
The results, along with those from other labs currently underway, will help determine whether or not existing Covid vaccines need to be altered to protect against omicron.
Sigal’s laboratory was the first to isolate the beta variant, a strain of the coronavirus that was identified in South Africa in late 2020.