1.South Africa remains in low transmission (<5 cases per 100,000 per day – slide 2). In response, the government this week removed all remaining public health measures (gathering size restrictions, traveller entry requirements and indoor mask mandates). While I have been supportive of this step, I think that one measure should have been kept. I remain concerned that South Africa’s vaccination coverage is still too low and feel strongly that our country should still have one key public health measure in place at this time – a vaccination requirement to enter public indoor spaces and public transport.
In the absence of an indoor mask mandate, we need to use vaccination as a way to reduce risk in indoor settings. To do this, everyone (>12 years) wishing to enter indoor public spaces or public transport, must provide proof of vaccination or a negative test result no older than 72 hours. The checking could be at the entrance (just in the same way that sanitising was checked on entry - instead of checking sanitising, the checking should now be for vaccination/test results). The vaccination proof will need to carried on the cellphone or physical card (just like driver’s license must be carried whenever driving). A negative test result can be either a PCR test or an antigen test. Outdoor sporting activities do not need this requirement but if the stadium has public indoor spaces as well, then the vaccination requirement should apply in the indoor spaces within the stadium.
I am concerned that vaccine uptake is going to reduce to a trickle soon - as the atmosphere in the country shifts gear to “Covid is no more in South Africa” as many will interpret the dropping of all restrictions as the end of the pandemic. The vaccination requirement will help to increase coverage and it can be dropped once SA has reached 70% vaccination coverage ie. when most people in indoor spaces will be vaccinated anyway.
I am also concerned that some are proposing that future regulations should only be enacted if there are severe acute hospitalisations and not be based on clinical cases as well. This approach is looking at Covid-19 with a 2020 understanding of Covid-19 - a disease that is a concern mainly due it leading to acute severe disease and death. In 2022, we need to understand that the virus does not only have acute consequences but also has quite severe long-term sequelae, even in those with mild infection initially. These long-term sequelae are not only the brain fog and malaise of long Covid, but raised risk of heart attacks, stroke, diabetes and neurological disease. This is explained in the attached affidavit I recently provided to explain why infections still need to be prevented with evidence-based interventions. So, looking at only severe illness to guide public health measures is inappropriate as it fails to consider the main effects (more common) of infection are long-term illnesses and so, it is important to prevent infections and to take evidence-based action to prevent infections.
There is some talk that South Africa has population immunity (or herd immunity) largely due to natural infection (50% adults vaccinated – slide 7 and probably another 30% have natural infection only) – but this is not correct for 3 reasons:
a.Immunity wanes with time and does not protect beyond a few months (natural immunity wanes faster than vaccine immunity & natural immunity is generally quite poor from mild or asymptomatic infections – which is most infections in omicron)
b.The omicron sub-variants can already escape immunity - next variants will very likely have high levels of escape from existing immunity (more from natural than vaccine-induced or hybrid immunity)
c.Existing immunity from past infection may do well in protecting from acute severe disease but it is not very good at preventing reinfection (especially in the case of omicron). Hybrid immunity with vaccination in those with natural infection provides much better protection.
2.Globally, case numbers have continued to decline (slides 13-14). I am somewhat surprised by this as I thought the rise in cases in Europe, UK, Australia and others due to omicron sub-variants may drive an overall increase in cases. In the meantime, Marothi is watching how our UK prediction is panning out compared to the real number of cases and so far in 1 week only, the prediction was on track.
3.Slide 16 shows how Omicron sub-variants are not impeded by 2 vaccine doses but are neutralised to a greater extent by 3 doses. Importantly, past infection with BA.1 provides diminishing protection against each subsequent new omicron sub-variants. BA.5 is a particularly wily escape artist in its ability to cause infection in those with past omicron BA.1 infection.
4.Slide 17 shows the importance of vaccination even when a person gets omicron infection. Omicron infection in unvaccinated people produces quite low Ab responses but produces good hybrid immunity in vaccinated people. So, vaccinated people who get Omicron get good protections against other variants.
5.Slide 18 is a wake-up call! It is a sobering and concerning finding. Reinfection worsens the many long-term sequelae of the first Covid-19 infection. So, those who had past infection need to still use public health measures to prevent reinfection. Further, reinfection shows a dose response, each additional reinfection episode increases the risk of cardiovascular disease, diabetes, neurological and pulmonary disease even further. If this bears out in the long-term, our health care services are going to be quite busy with these medical illnesses in a few years from now.
6.Slide 19 provides further evidence of the mortality benefits of Covid-19 vaccines in case anyone is still not convinced that we need to do everything we can to increase vaccination. In the first year of vaccination, 19.8 million Covid-19 deaths were averted ie. a reduction of 63% of the expected deaths. Even more deaths could have been averted in vaccine inequity did not hold back some countries.
I hope you found today’s missive interesting, and if you are still pondering slide 18 and the need for a vaccination requirement to reduce indoor transmission risk, especially now that masks have been dropped, then I have been successful in drawing your attention to some important issues that we are facing in Covid-19 today.
Salim S. Abdool Karim, FRS
CAPRISA Professor of Global Health: Columbia University