New Understandings: Omicron before the New Year

The last week has seen the Omicron variant of SARS-CoV-2 move throughout Europe at terrifying speed, as well as being found in most American states. While the severity of the disease caused by the variant still seems to be lower than previous iterations of the virus, its extreme capability for transmission has made it just as dangerous, if not more, as previous waves of the virus for public health systems around the world. The scientific understanding of the variant continues to grow however – we will discuss new insights here.

New Scientific Insights

Research carried out by the University of Columbia further piles on the evidence of the immune escape Omicron is capable of after showing its ability to cause breakthrough infections in individuals who have received any of the four major vaccines (Pfizer, Moderna, AstraZeneca or Johnson & Johnson). It also showed the reduced effectiveness of approved monoclonal antibody treatments against the variant, further elucidating immune escape. The study was the first to provide formal assessments of the Moderna vaccine against Omicron, though research carried out by Duke University in partnership with Moderna has also demonstrated its drastically lower efficacy against Omicron without a booster.

On the novel vaccination front, research published in Nature demonstrates the possibility of intranasal booster vaccines. While intranasal vaccines had previously been investigated, the immune responses they generated were not as immunogenic throughout the body. The paper found that when administered as boosters subsequent to systemic vaccinations, they can be efficient at provoking immune responses that neutralize the virus in the mucosal layers before it can infect epithelial cells, which could likely lower the frequency of breakthrough infections in vaccinated people. Further investigation could lead to the commercialization of this much simpler form of immunization, easing the logistics of boosters.   

Last week, a research study at the University of Hong Kong found that the Omicron variant is much better at infecting the bronchial airways rather than deeper parts of the respiratory system – unlike Delta and the wild-type variants. While the study has yet to be peer reviewed, it shows promising findings, particularly because such a localization pattern would be conducive with lower disease severity. However, it remains important to note that even with reduced clinical impact per patient, the clinical burden of Omicron will remain highly substantial owing to its infectiousness, much like the author of the study, Michael Chan-Chai mentions:

“By infecting many more people, a very infectious virus may cause more severe disease and death, even though the virus itself may be less pathogenic”

Omicron Sweeps Europe

The evidence of milder disease does not remain incontrovertible, either. A report compiled by Imperial College London last week found no evidence for different risks of hospitalization or symptoms between the Delta and Omicron variant, while underscoring the more than 5 times greater risk of re-infection by Omicron compared to Delta. The difference in severity is markedly lower in unvaccinated people – but also in individuals who are past the date of their next vaccination by two weeks. Indeed, the effects of this are being felt acutely in the United Kingdom, particularly in London – with a doubling time of ~2.5 days, Dr. Susan Hopkins, the chief medical adviser for the UK Health Security Agency, has warned that infections could reach 1m per day by the end of the month.

As the UK continues to see record numbers of cases with each passing day, the situation is reflected in the rest of Europe. The Netherlands have already imposed a lockdown, with Italy considering fresh measures, France debating the introduction of vaccine passports, and Germany contemplating mandatory vaccination. The situation is also escalating in America, with over a 50% rise in infections since the beginning of December in the USA. The World Health Organization reflected this sentiment, with Omicron having been detected in over 89 countries, with a doubling time ranging from 1.5-3 days in established areas. 

Policy Responses to Omicron

Research conducted on the effectiveness of restrictive measures, done by the London School of Hygiene and Tropical Medicine, paints a sobering picture. Their predictions postulate that under the most optimistic scenario, where Omicron is assumed to show low degrees of immune escape and a very high degree of booster effectiveness in Britain, new restrictions will still be required to bring the rate of hospitalizations and deaths under control by April 2022. The severity of social distancing measures required if these assumptions are not true increases drastically if the nation is to maintain the peak of infections below those of January 2021. 

Conjointly, recent research from breakthrough infections in Germany shows that booster vaccinations are not sufficient to prevent infection or symptomatic disease – but they remain effective at preventing severe disease. These findings are concordant with previous research on current vaccines, and underscore the need for updated immunizations that provide more generalized immunity across variants, or target more specific variants of concern. 

The increasing need for boosters also highlights the extreme demand for vaccination products and manufacturing on a global scale. A survey conducted by AccessIBSA and Medecins Sans Frontieres indicated that up to 120 manufacturers are ready to produce mRNA vaccinations across Asia, Africa and Latin America – regions which still have lower rates of immunization than the developed world. It is critical to highlight that increased partnerships in industry to bring up the levels of vaccination throughout the world will remain paramount to preventing further novel variants from emerging. 

As another week goes by and further news about the nature of the Omicron variant emerges, it becomes increasingly clear that earlier fears about Omicron have been proving to be true, although silver linings remain regarding the possibility of lower clinical severity. But this should not be cause for complacency – as it becomes abundantly evident that its higher transmissibility presents a grave danger that may require further restrictions once again. A key take-away lesson is that while vaccinations remain important, so does the need to liberalize the industrial process to manufacture them in a way that makes them accessible worldwide, and the need to further innovate more efficient products. 

Nick Zoukas, Former Editor, PharmaFEATURES