SAFETY OF THE SINGLE-DOSE Ad26 SARS-CoV.2 vaccine (JNJ vaccine)
24th December 2021
Pretoria: The National Department of Health has noted the Center for Disease Control (CDC), USA expressing a preference of the mRNA vaccine over Johnson and Johnson’s COVID-19 vaccine.
This is in the context of the USA having an abundance of vaccines, with over 100 million doses in the field for immediate use. The Advisory Committee on Immunization Practices (ACIP) noted during their review that any vaccine is better than being unvaccinated, and those who are unable or unwilling to receive an mRNA vaccine would continue to have access to the J&J COVID-19 vaccine.
The decision made in the context of rare adverse events and an abundance of mRNA vaccines in the USA should not undermine the roll-out of the J&J vaccine in other parts of the world. The South African Medical Research Council (SAMRC) analyzed safety data from the Sisonke Study (an open-label phase 3b implementation study that delivered almost 500 000 doses of J&J vaccine to health care workers) by monitoring adverse events (AEs) at vaccination sites, through self-reporting triggered by text messages after vaccination, health care provider reports and by active case finding.
The frequency and incidence rate of non-serious and serious AEs were evaluated from day of first vaccination (17 February 2021) until 28 days after the final vaccination (15 June 2021). Of 477,234 participants, only 10,279 (2.2%) reported AEs. Serious sideeffects were rare and occurred in only 129 health care workers. The commonest side effects were headache and body aches, followed by injection site pain and fever, and most occurred within 48 hours of vaccination.
In terms of rare events, the SAMRC saw two cases of Thrombosis with Thrombocytopenia Syndrome (TTS) (blood clotting) and four cases of Guillain-Barre Syndrome. There were no deaths due to the TTS or the Guillain Barre Syndrome. “Serious AEs and AEs of special interest including vascular and nervous system events, immune system disorders and deaths occurred at lower than the expected population rates” says Prof Glenda Gray, co-National Investigator of Sisonke.
“Our safety data demonstrates that this vaccine was well tolerated and that all the rare events associated with the J&J vaccine were well managed, demonstrating that in low and middle income countries (LMICs), this single dose vaccine has great utility” says Prof Linda Gail Bekker, co-national lead on the Study.
There is no reason for widespread concern. Most of the reported adverse events have been minor, local or systemic reactions. Blood clotting is an extremely rare complication affecting between 1 and 4 per million people who are vaccinated.
Despite the fact that the United States has suspended use of the J&J vaccine for now, some countries like France and Poland have weighed the risks and chosen to continue to provide the J&J vaccine while this rare side-effect is considered. As with the FDA in the United States and the EMA in Europe, our regulator, South African Health Products Regulatory Authority (SAHPRA), is working with the Sisonke team around the clock to ensure that all appropriate precautions are taken.
The Sisonke 2 Study has now administered over 230 000 second doses of the J&J vaccine, both prior to and during the omicron wave. The preliminary short-term analysis indicates that two doses of J&J have been found to be protective against hospital admissions with vaccine efficacy data (VE) for hospital admissions at least equivalent to other vaccines.
Therefore, the Department of Health is satisfied that the J&J vaccine continues to provide much hope to South Africans.
This data and other the dossier of evidence from international data are being evaluated by SAHPRA and the approval of booster vaccinations with J&J vaccine is anticipated in the coming days.
Statement issued by Mr Foster Mohale, National Health Department, 24 December 2021
