Since Imperial’s Professor Danny Altmann claimed three weeks ago, based on a recent paper from his university, that Omicron does not provide natural immunity against reinfection, this claim has been repeated around the world and become an accepted part of the Covid narrative, frightening people into believing the pandemic may never be over. Professor Altmann wrote in the Guardian:
Rather than a wall of immunity arising from vaccinations and previous infections, we are seeing wave after wave of new cases and a rapidly growing burden of long-term disease…
Importantly, Omicron infection was a poor booster of immunity to further Omicron infections. It is a kind of stealth virus that gets in under the radar without doing too much to alert immune defences. Even having had Omicron, we’re not well protected from further infections…
Contrary to the myth that we are sliding into a comfortable evolutionary relationship with a common-cold-like, friendly virus, this is more like being trapped on a rollercoaster in a horror film.
At the Daily Sceptic we pointed out that Professor Altmann’s interpretation of the paper’s findings was flawed and not in line with what it said or showed. The paper actually did show a robust immune response following Omicron infection.
Now, two new studies from Qatar provide real-world evidence of the power of natural immunity against Omicron.
The first study looked at all confirmed SARS-CoV-2 infections in Qatar from February 2020 to June 2022, comparing Covid incidence and severity among those with and without a previous infection (all in the study were unvaccinated). The pre-print study (not yet peer-reviewed) found that pre-Omicron Covid provided 85.5% protection (CI: 84.8-86.2%) against pre-Omicron reinfection, though waning to around 70% after about a year and a half. This is in line with earlier studies.
Against Omicron reinfection, a pre-Omicron infection provided 38.1% protection (CI: 36.3-39.8%), though declined with time possibly to negligible levels after a year and a half.
Importantly, pre-Omicron infection provided very high protection of 97.3% (CI: 94.9- 98.6%) against severe, critical, or fatal COVID-19 reinfection by both Omicron and pre-Omicron Covid, with no evidence of waning after 14 months. While Qatar’s population is younger than most, a very similar result of 95.4% protection was found for the over-50s, again with no evidence of waning. This suggests that Covid quickly becomes like a circulating cold after the population has had it once.
But what about Omicron reinfection after an initial Omicron infection – what protection does that provide? Professor Altmann claims the immune response following an Omicron infection is negligible and Omicron is a “stealth virus” that evades immunity and doesn’t protect against reinfection. However, the second study from Qatar shows this is not true at all.
The pre-print (not yet peer-reviewed) used a test-negative, case-control design to look at infections in Qatar between May 7th and July 4th 2022, with particular attention give to the period June 8th to July 4th when Omicron BA.4 and BA.5 dominated. It found that an initial Omicron infection against BA.4 and BA.5 reinfection provided 79.7% protection (CI: 74.3-83.9%), not far off the protection of pre-Omicron infection against pre-Omicron reinfection found in the first study (85.5%). The study also found that an initial pre-Omicron infection provided 28.3% protection (CI: 11.4-41.9%) against BA.4 or BA.5 reinfection, broadly in line with the first study (given the later time and newer variants).
Professor Altmann and others who claim Omicron infection does not provide immunity against reinfection are therefore spreading misinformation by exaggerating the threat from the virus and downplaying the prospects for population immunity and moving on from the pandemic.
The authors of the second study say there were too few serious cases to draw any conclusions about protection from severe disease and death. However, considering the 80% protection against reinfection, there is no reason to think the protection an Omicron infection provides against serious disease will not, as with pre-Omicron infection in the first study, be similarly robust and long lasting.