- Booster doses of the J&J vaccine are currently being offered to healthcare workers across South Africa.
- It is only available to Sisonke participants who received a single J&J vaccine shot this year.
- The lead investigators are urging all eligible health workers to receive their booster before the fourth wave.
Booster doses of the Johnson & Johnson (J&J) Covid-19 vaccine are available to the 494 424 healthcare workers in South Africa who received their initial dose during the first phase of the study between February and May 2021.
Speaking at the Covid-19 digital briefing on Friday, health minister Joe Phaahla said that close to 84 000 health workers have already registered and consented to participate in the Sisonke 2 study.
However, just over 9 000 health workers have gone on to receive their booster doses.
Phaahla said: “We are hoping that all the [494 424] health workers who received the Sisonke 1 [dose] will come forward to participate in the Sisonke 2 study. The results of this study will give us a better indication of the role of booster doses.”
Getting their booster dose
Healthcare workers eligible for the booster dose will give consent to partake in Sisonke 2. They will then receive a Vaccine Voucher for their booster shot. There are both public and private Sisonke vaccine sites which can be found on the findmyjab website.
Encouraging data on J&J booster
Co-lead investigator of Sisonke and President of the South African Medical Research Council (SAMRC), Professor Glenda Gray, said that the decision to give an additional shot was based on data showing that a two-dose regimen of the vaccine had a good safety, immunogenicity and efficacy profile.
According to a press release earlier this month, the J&J ENSEMBLE 2 clinical trial evaluated two doses of the vaccine given 56 days apart. The results showed that it provided full protection against severe Covid-19, and 75% protection against moderate to severe disease globally. The booster shot was also shown to increase antibody levels.
“[The data] shows the second dose of J&J vaccine is durable, so we’re very excited to give a science- and evidence-based boost to our healthcare workers,” she said. Gray encouraged healthcare workers to come forward to receive their additional dose.
Easier rollout of Sisonke 2
Professor Linda-Gail Bekker, who is the co-lead investigator of the Sisonke study, alongside Gray (and deputy director of the Desmond Tutu HIV Centre at the Institute of Infectious Disease and Molecular Medicine, University of Cape Town) said that while Sisonke 1 started off very slowly with just 18 sites, it is different with the current study.
“The good news is that with Sisonke 2, because of all the experience of the national rollout to date, we’re starting in all nine provinces with up to 400, and more, sites. In every district there should be an opportunity [for health workers] to receive a Sisonke 2 boost,” she said.
Bekker added: “We don’t, therefore, expect the queues that we did see before, but there is a limited time offer for this and so we want to encourage our colleagues to move quickly to download their vouchers and make sure that they get to the sites in order to get their boost ahead of the fourth wave.”
Results will help inform government on boosters
The Sisonke 2 study will help researchers establish how to move forward with the boosting strategy in South Africa, said Gray. And to move forward with the boosting strategy, the government requires evidence.
Gray said: “And so our job as the Sisonke team is to provide the government with very important evidence of how good these vaccines were in the field, and what the timing of the vaccine [doses should be].
“Healthcare workers will consent so that we can use their data to show the government the effectiveness of this. … Based on this data that Sisonke gets, this will help inform the government on how to do booster shots in the future, and so it’s very important for us to get this data to the government by 15 December.”
Addressing hesitancy and concerns
Gray addressed concerns around fertility, pregnancy, and impotency.
She stressed that before any vaccine goes into a human being, there are rigorous preclinical studies done on the teratogenicity reproductive toxicity, which refers to whether a product contains any substances that may produce defects in the foetus after it is administered to a pregnant woman.
“Before a vaccine can even get into a human being, there are extensive studies done in animals that have been well-validated and are accepted at a global level,” said Gray.
“This preclinical data is available to all the regulatory authorities. If you go onto any website of the CDC or the FDA, you can see the dossiers that explain this data. And we’ve also reassured that the platforms that have been used (for the J&J vaccine) have been used for other vaccines, and the same preclinical testing and teratogenicity has been done in that,” she added.
That data, she explained, has shown that the vaccines cannot cause sterility or impact a woman’s ability to fall pregnant.
Bekker also commented, noting that the development of the vaccines followed a very regular process and that, despite their rapid development, the designs were all tried and tested and have been used in all kinds of drugs and vaccines.
“Sahpra also considered all of that data before considering these vaccines for use. It’s important to reassure the public that no corners were cut in getting these vaccines,” she said.