Study affirms J&J vaccine efficacy against death, hospitalisation

Friday, August 6, 2021

The results of the Sisonke programme study have revealed that the Johnson & Johnson vaccine has provided effective protection against serious illness and death from COVID-19 infection.

This was on Friday revealed by Professor Glenda Gray, the CEO of the Medical Research Council and co-lead investigator, during the Health Department’s weekly briefing.

The study commenced on 17 February 2021 and concluded on 17 May 2021. The trial reached over 470 000 healthcare workers in over 120 sites across the country.  

The vaccine, Gray said, proved effective against the Beta and Delta variants, which are both prevalent in South Africa.

An analysis of the data, which was done in three ways, looked at the effectiveness of the vaccine.

"We want to look at the infections that we get - and we will get breakthrough infections. We want to make sure that we understand whether these breakthrough infections were mild, moderate or severe," said Gray.

While results of one analysis are outstanding, Gray said the first two were obtained from medical insurance and provincial PERSAL databases.

"When we look at the evaluation effectiveness, we start looking at the vaccination protection 28 days after receiving the single dose J&J vaccine. We closed our analysis for this on the 17th of July in the middle of the Delta wave.

“The reason we chose the first analysis at this time is our co-workers were getting anxious, and were worried that the vaccine may not be protecting them," Gray said.

She said the study group will continue to have an ongoing analysis of the Sisonke programme for up to two years, as this will allow them to be "able to see how durable and effective this vaccine is over time".

On effectiveness against death, Gray said the latest data show protection of between 91% to 96.2% of inoculated healthcare workers.

"This was our primary endpoint. We're able to say that this vaccine protected health workers against death.”

The study group then looked at whether J&J provided protection against the Delta variant.

"When we started the vaccine rollout, we knew that the Beta variant was circulating in our country, and then over time, the Delta became the variant of concern.

“You can see quite profoundly that the vaccine protected both against the Beta and Delta variants,” she said.

The vaccine, Gray said, has greater efficacy against the Delta variant.

The J&J vaccine data recorded between 65% and 66% protection against hospitalisation, and between 91% and 95% protection against death.

"When breakthrough infections happen, they happen to be very mild - around 96%. In terms of severe illness and death, these have been less than 0.05%,” Gray said.

The J&J vaccine, Gray affirmed, is safe.

“There's no statistic that has been detected in this cohort of people [health workers] at a global level. The side effects that we see are completely in line with what we're seeing globally.

“We have seen some rare adverse events that have been reported at a global level... once you actually [vaccinate] millions of people. We continue to evaluate the safety of the J&J vaccine.”

She said based on laboratory data, the vaccine is showing “good durability", giving an indication that there is currently no need for a booster at this stage. –