As more and more data become available of the effectiveness of COVID-19 vaccines to prevent severe disease and death, South Africa will today (10 September) start its first vaccine trial in children. This was confirmed last night by SAMRC President and CEO, Prof Glenda Gray at the weekly webinar presented by Discovery Health together with SAMA, UFFP and SAPPF.

In her presentation relating to data around the effectiveness of the COVID-19 vaccines, vaccination in children and whether booster shots are needed for fully vaccinated people, Prof Gray, confirmed that the phase 3 trial in children aged between three months and 18 years will be done at multiple sites in South Africa, starting at the George Mukhari Hospital. The study will enrol 2000 children in South Africa and is part of a trial that includes a total of 14 000 children from several other countries including Kenya, Chile and Malaysia.

The vaccine to be used is Chinese company, Sinovac Biotech’s two-dose Coronavac jab that SAHPRA approved for emergency use in adults 18-59 years earlier this year. Paediatric participants in the study will receive two doses of the vaccine 21 days apart to evaluate its efficacy, tolerability, and safety in the targeted age group.

Prof Gray stressed that several countries such as the US, France, Cuba and Chile have already started vaccinating children, mostly >12 years.

She said one of the biggest concerns is growing global data showing that more and more children are getting infected with many of them suffering from multisystem inflammatory syndrome (MIS-C) after contracting COVID-19. This serious and sometimes deadly condition causes inflammation in  different body parts including the kidneys, brain, gastrointestinal organs, heart and lungs.

According to Prof Gray, the decision to use the Coronavac vaccine for the trial in children is based on data that show that it may have less side-effects after reports of myocarditis in young people who have received the Pfizer vaccine emerged. However, these cases are extremely rare with the data showing that in girls aged between 16 and 19 a total of around eight cases of myocarditis can be expected per one million doses administered in this age group and that it is slightly higher in males.

“We have to weigh this up against the other data that showed that the Pfizer vaccine prevented 77 800 coronavirus infections and more than 520 hospitalisations and 100 deaths in this age group,” Prof Gray noted.

Vaccine effectiveness in healthcare workers

Referring to data coming out of the Western Cape on the effectiveness of the JnJ vaccine among healthcare workers, Prof Gray said that it showed unequivocally that it offers excellent protection against severe disease, hospitalisation and death. Among unvaccinated healthcare workers, there was one death in 480 who contracted the virus while only one death in 1490 vaccinated HCWs was recorded. This means that the risk of death in unvaccinated HCWs was 3.3 times higher than in those who were vaccinated.

In the general population in the Western Cape, data obtained for the week 14 to 20 August showed that in the over 60 age group, of the 2455 cases that were reported, 92% were unvaccinated while 96% of those who were admitted to hospital and 98% of those who died were unvaccinated.

Data from a Discovery Health database of its members that have been fully vaccinated with the two-dose Pfizer vaccine showed similar results, which are in keeping with current global data, Prof Gray said.