Sisonke study

The JnJ vaccine was tested in a large trial of almost 44 000 people from four continents, of whom 7000 participants came from South Africa. The follow-up time corresponded with our second wave, so the study was able to provide a good picture of how the JnJ vaccine works against the new 501Y.V2 variant, which is dominant in South Africa. This variant has been responsible for around 9 in 10 of all COVID-19 infections detected during the second wave and it is known to spread more rapidly than previous variants. The South African part of the trial showed that while the JnJ vaccine is not going to prevent mild symptoms, it provides 57% protection against moderate-severe disease, 85% protection against severe disease and 100% protection against death. By way of comparison the Oxford-AstraZeneca vaccine provided only 27% protection against mild to moderate COVID-19 caused by the new 501Y.V2 variant. The Oxford-AstraZeneca trial was not designed to investigate protection against severe COVID-19 and it remains unknown how effective it will be in doing this. As such, the Oxford-AstraZeneca vaccine may still play a valuable role in our Vaccination Programme in the future. The Oxford-AstraZeneca vaccine is additionally in the process of being updated to make it more effective against the new variants emerging all over the world. In the meantime, it is wise to start with a vaccine that we know protects against severe COVID-19 caused by the 501Y.V2 variant dominant in South Africa.

Like all COVID-19 vaccines, the JnJ vaccine contains instructions for the spike protein on the coronavirus. These instructions are delivered to our immune system by a modified adenovirus that has also been used in other vaccines, such as the Ebola and Zika vaccines. The adenovirus is safe to use in vaccines as it has been modified so that it cannot cause disease or replicate in humans. Nonactive ingredients in the JnJ vaccine include sodium chloride, citric acid monohydrate buffer, polysorbate 80, 2 hydroxypropyl-β-cyclodextrin (HBCD), ethanol (absolute), sodium hydroxide and water for injection. All of these ingredients are safe for human consumption. The vaccine does not contain any animal products and is halal.

When injected, the vaccine trains your immune system to fight the virus that causes COVID-19. The vaccine does not contain the coronavirus and will not give you COVID-19. People often develop some mild side-effects like tenderness at the infection site, feeling unwell, feverish and a headache for a few days. These are positive signs that the body is mounting an immune response to the coronavirus. The technical term for this is ‘reactogenicity’. When you encounter real coronavirus particles in future, your immune system will be able to disarm the virus so that you either do not fall ill at all, or if you do, the symptoms are mild and your chances of being hospitalised or dying are much lower.

The vaccine has a long shelf life of 2 years at -20 degrees Celsius and can be safely stored in a domestic fridge for 1 month. This makes it suitable for widespread rollout in warmer countries like South Africa as ultra-cold freezers are not needed.

The JnJ vaccine is given as a single dose into the upper arm. Protection starts around 10-14 days after vaccination, and even as early as 7 days for severe disease. Protection rises to good levels around a month after vaccination. The JnJ vaccine is the only COVID-19 vaccine currently available that only uses a single dose. Other COVID-19 vaccines currently require two doses. No vaccine provides 100% protection. The JnJ vaccine is thought to provide 57% protection against moderate-severe disease, 85% protection against severe disease, and 100% protection against death. We are still waiting for further results on how effective the vaccine is at preventing asymptomatic transmission. It is important you continue to use masks, practise social distancing and good hand hygiene. If you are a healthcare worker, you still need to wear your PPE and stay vigilant, even after you are vaccinated.

Manufacturers apply for vaccines to be licensed after trials show them to be safe and effective. The JnJ trial results were released in early February and applications for licensing are underway in the US, Europe and South Africa. The Sisonke Programme allows the government to make this safe and effective vaccine immediately available to healthcare workers using a research programme. Sisonke is not the same as a clinical trial. Rather it is a way that research can help to make it available while the licensing process takes place. The South African government has chosen to move ahead with this programme because it would be unethical to withhold a vaccine known to be safe and effective. The South African Health Products Regulatory Authority (SAHPRA) has approved the use of the JnJ vaccine for the Sisonke Programme while it processes the full licensing. It is important to understand that the fact that it is not yet licenced does not mean that it is not safe or effective. A third wave of COVID-19 is predicted to begin in South Africa this winter. Protecting healthcare workers is a priority and so we must start vaccinating our healthcare workers before the third wave arrives.