Data on the severity of Omicron is evolving, and this is a good news-bad news situation.

Data coming out of the first four weeks of Omicron in Gauteng, South Africa suggesting there is less severe illness with Omicron compared to Delta. This is great.

However, total number of hospitalizations higher than Delta wave because of sheer number of infections. This is not so great. Healthcare capacity is a concern and will be for next weeks.

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We don’t know if this difference in lower severe illness is due to previous infections, vaccinations or lower virulence of Omicron, or in fact a combination of all three.

However, the impact on children is concerning. This is consistent with recent articles showing a steep jump in hospitalizations of children in many states in the US as well as in many countries in Europe. The one reassuring piece of information is that it does not seem to be more severe than Delta, and may possibly be less severe than Delta. But once again, due to a large number of cases, more children are being hospitalized, predominantly kids who are unvaccinated.

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So what about Delta now? While people with previous Delta infections can be infected with Omicron, data from the Sigal lab shows Omicron infection enhances neutralizing immunity against Delta.

While we don’t know if this is because Omicron induced antibodies are able to neutralize Delta or if it’s simply activation of antibody immunity from vaccination, it still is really positive news for two reasons:

1. We wont see a syndemic, Omicron will likely overtake Delta altogether and,
2. Shows importance of being vaccinated despite Omicron transmission.