Eight months ago, just under half a million healthcare workers in South Africa were vaccinated with one shot of Johnson & Johnson (J&J) in the country’s Sisonke implementation trial. Now they’re getting an extra shot of the J&J jab in a new leg of the study.
The South African Health Products Regulatory Authority (Sahpra) approved the Sisonke researchers’ request to give health workers a second Johnson and Johnson jab.
Health workers have been eligible for a booster since 9 November 2021.
What is a booster?
Each Covid vaccine comes with its own recommended dose.
You’re considered fully vaccinated after just one shot of the J&J jab.
Those who get the Pfizer vaccine are considered completely immunised after getting two shots.
Some countries like the United States and Israel, have decided to give an extra shot to some of those who are already fully vaccinated.
Extra doses are called “booster” shots. They are additional jabs given to people already fully immunised.
Why would you need a booster?
Elderly people or those with weak immune systems may need extra shots.
How does a country decide if they need boosters?
The need for boosters depends on what a country’s Covid outbreak looks like, which variants are circulating and how well the vaccines in use protect people against those variants.
The World Health Organisation (WHO) says there are three things nations should look at when deciding on booster shots.
The first is waning immunity. There is a possibility that the protection against falling very ill with Covid may begin to drop over time.
But there is not yet enough data on the immune response to the jabs to know for sure if vaccines’ protection becomes weaker over time.
The WHO says we also need to look at whether vaccines are able to prevent people from getting infected with SARS-CoV-2, the virus that causes Covid-19.
Real-life data so far has been promising. It shows that fully vaccinated people are far less likely to get infected with SARS-CoV-2.
No jabs are, however, 100% effective in preventing infection with SARS-CoV-2. the virus which causes Covid-19. So you can still get Covid after you've been fully vaccinated. The jabs, however, do make you less likely to get infected.
Can you mix different Covid vaccines?
In October, the US Food and Drug Administration cleared J&J’s jab to be used as a booster.
The US regulator also approved the “mix and match” use of vaccines.
This means people who received Pfizer’s two-dose vaccine initially would be able to get J&J for their third (booster) dose.
Those who got J&J’s one-dose vaccine can be given a Pfizer shot as their second dose.
A preprint study showed that people who started off with a J&J shot were better off with a Pfizer booster.
But it didn’t make a difference what jab was used as a booster for those who were first immunised with Pfizer.
The health department announced in October that it will offer Pfizer jabs as second doses to people from South Africa who had received a first jab of the Moderna or AstraZeneca vaccines in a different country.
Sahpra has, however, not yet approved a mix and match policy for South Africa.
The health department says health workers who participated in the Sisonke study, will - eventually be able to choose between a J&J and Pfizer booster as a second shot after a 1st J&J jab, but no final details have been announced.