Prof Salim Abdool Karim Weekly COVID-19 UPDATES

17 February 2022

The global omicron wave is declining fast - as expected (Slide 1). In South Africa, BA.2 has continued to increase as a fraction of all circulating viruses. The initial outbreak of BA.2 in South African schools that caused a small bump in cases a few weeks ago has settled and the downward trajectory continues though slower than anticipated, likely due to BA.2 (Slide 2 & 3).

Given that South Africa is in its 3-month inter-wave low transmission period, if the trend of the past 2 years continues, this is a very good time to ease restrictions. Many of the country’s Covid-19 prevention measures can be stopped eg. outdoor mask mandates, sanitising and most social distancing can be scrapped. However, 4 measures probably need to be maintained (or introduced) in anticipation that a new variant could reach us sooner than anticipated, in which case we do not want a new variant to spread widely rapidly even before we know about it:

  1. A limitation on indoor gathering size (no cap on outdoor gatherings)
  2. The indoor mask mandate needs to continue
  3. A vaccination requirement for entry into indoor spaces, especially for indoor spaces where masks have to be removed, like restaurants, gyms, etc.
  4. A vaccination requirement for those in congregate settings eg. schools, prisons, factories, etc.

In easing restrictions, we need to be careful that this is not understood as the pandemic is over – instead, we need to make it clear that restrictions need to be adjusted as the pandemic changes and that we don’t know what the next variant looks like.

On the vaccination requirement, in delivering presentations on Covid-19 vaccines to the staff and/or management of several large companies (De Beers, Old Mutual, AngloAmerican, etc) recently, I have been struck by the questions raised. I have found it to be both interesting and educational doing these presentations as they have given me a better understanding of issues being raised by the vaccine hesitant. The questions from the anti-vaxx lobby are not worth repeating here. The two most common questions I get are 1) “Why should I get vaccinated…”  and 2) Since I heard that past infection has given South Africa population immunity, why do I need to vaccinate when I have had Covid before?”

The first question is often accompanied by sub-text, such as, “….when new variants still cause infection in vaccinated people.” or “…when immunity wanes anyway” or “…when omicron is a mild virus anyway.”

In case you are also coming across these questions, I have attached some slides to help you answer them. In slides 6 to 15, I outline the 8 benefits of Covid-19 vaccines (there are more but I have focused on just these 8). Five of the 8 are personal benefits – benefits enjoyed by the vaccinee. The remaining 3 are community benefits. An important point is that level of each benefit varies by vaccine type and by variant type (slide 9 illustrates this point).

Regarding the second question, the paper in slide 16 was published this week in the NEJM. It provides the cumulative risk of Covid-19 in almost 150,000 people with past infection comparing vaccinated and unvaccinated people. Vaccination reduces Covid-19 by 82% in those with past infection – showing the clear benefit of vaccination in those with past infection.

Finally, a macaque study by the VRC (Slide 17) provides some early evidence that an omicron version of the Moderna vaccine does not provide better protection against omicron than the current version of the Moderna vaccine. This suggests that Covid-19 prevention may not likely benefit from a similar strategy to flu-vaccine, where modified versions of the vaccine are needed regularly. Repeat doses of the original vaccine are providing protection against omicron. But, it is not known how long immunity lasts after a 3rd dose booster. Fortunately, several other vaccine strategies are currently being developed (eg. pancoronavirus vaccine approaches) and some are already in trials.

Salim S. Abdool Karim, FRS
Director: CAPRISA
CAPRISA Professor of Global Health: Columbia University