According to the South African Covid-19 Modelling Consortium (SACMC), the size of fourth wave has been expected to be smaller than third wave due to the absence of a new variant.

The SACMC is coordinated by the National Institute for Communicable Diseases (NICD) on behalf of the National Health Department, and its projections take into account the progress of the vaccination programme so far, the impact of changes in public health and social measures (PHSM), population behaviour, and a hypothetical new variant of concern (VOC).

“If increases in contacts occur in January, as opposed to November, later and smaller waves are expected as a larger proportion of the population will be vaccinated. It is important to note that smaller peaks in (hospital) admissions do not necessarily imply that future waves will have less impact on the health system and health care workers,” the SACMC report notes.

Whether or not the admissions will result in overwhelmed hospitals and avoidable Covid-19 deaths also depends on how much hospital capacity can continue to be made available.

“There is large variation between the… scenarios, emphasising the impact that individual behaviour and a potential new variant of concern with relevant immune escape properties can have on the size of the next wave, as well as its timing.”

“With high seroprevalence and vaccination coverage assumed to reach 70% by the end of March 2022, a given number of infections will translate into substantially reduced numbers of severe cases and admissions, relative to what was seen in previous waves. Thus, while admissions may be projected to be low, seizable waves of infections, and therefore detected cases, may still occur.”