This week it is unavoidable not to mention omicron and so we’ve decided to dedicate our issue of “5 things in life sciences” to this very topic.
In a twist from all of the articles about “what we know” about the new variant, however, we thought the community would be better served to talk about what we don’t know quite yet about the newest variant that is now in two dozen countries. Here are five things we’re pondering.
How quickly will omicron be pervasive in the U.S.?
As soon as news of the new variant began circulating on November 26, some of the first questions asked were “will omicron make it to the U.S.?” and “if so, when?” The reality is that in our globally connected economy and with a virus as transmissible as COVID-19, the answer continues to be, yes, any new variant will show up in the U.S. and it will do so in a matter of days or weeks. The entire globe is in the same situation, and while unsettling, this is the new reality of our endemic future with COVID-19. The question now becomes, how quickly will omicron replace other variants?
The first confirmed case of omicron in the U.S. was identified in San Francisco on December 1, in a vaccinated individual (no booster shot) who left South Africa on November 22. As with many of the previous variants, once they start to circulate they often become the dominant strain, which epidemiologically is what viruses have evolved to do. For perspective, South Africa’s National Institute for Communicable Diseases stated that 74% of the COVID-19 genomes sequenced in November belonged to omicron. Delta was the dominant variant throughout October. The same shift in variants was seen from alpha to beta to delta, and it is the same shift that we see on an annual basis with influenza. It is likely that omicron will have a high occurrence rate throughout the U.S. over the coming weeks, which is something to be monitored and assessed, but also something to get accustomed to as the virus ebbs and flows. Precautions such as masking, social distancing and most importantly vaccination and boosters, continue to be the best tools to combat the virus and minimize the severity of infections.
In parallel to determining to what extent, if any, omicron eludes existing vaccines, the vaccine makers have started efforts to fight the variant if needed. Pfizer, BioNTech and Moderna have indicated that they have already started work on developing new versions of their vaccines that target this variant. These companies have said that they expect to be able to be ready with an updated vaccine within 100 days. This is possible because the mRNA platforms they are using can quickly be updated to encode for the variants spike protein, while the remainder of the manufacturing process remains unchanged. It is also possible because the FDA has already issued guidance on what is required to gain approval for vaccine updates to fight new variants.
Will omicron evade existing vaccines or treatments?
When evaluating variants, emphasis is placed on mutations in the gene that encodes the virus’s spike protein, which plays a critical role in the variant’s ability to enter cells and evade antibodies. Each existing variant of concern carries multiple mutations affecting the spike protein, which brings into question whether existing vaccines or treatments will be effective in preventing infection. The omicron variant is characterized by 30 or more changes in the spike protein. As seen with the delta variant, vaccine effectiveness is generally lower with emerging variants (from 89% in alpha to 79% in delta when preventing symptomatic disease); however, it isn’t clear how much of that lower effectiveness is attributable to waning protection over time versus mutations in the variant.
As is to be expected, leaders from across the globe are weighing in on the effectiveness of vaccines in protecting against the omicron variant. The Moderna CEO has predicted that existing vaccines will be much less effective against omicron. In an interview with Bloomberg Television, the Pfizer CEO indicated that he didn’t expect a significant drop in the effectiveness of Pfizer’s vaccine, but that it would take a few weeks for the initial data analyses to come back. While not a vaccine, GSK has indicated that preclinical data suggests its monoclonal antibody treatment may be effective against the new omicron variant. Conversely, the Regeneron CEO indicated that its monoclonal antibody treatment may be less effective against the new omicron variant.
As evidenced by the existing diversity of opinions, more time is needed to develop data-driven insights into the effectiveness of existing vaccines and treatments against the omicron variant.
Is omicron more transmissible than delta?
Epidemiologic studies are underway but at this stage it’s too early to determine if omicron is more transmissible. There are numerous factors that contribute to the transmission of a virus including environmental conditions, viral load, host behavior, host defense mechanism and virus infectivity. These factors differ by region and populations. Until further studies are completed it is too early to determine if omicron will be more transmissible than delta on a global scale.
On November 26, the World Health Organization classified omicron as a variant of concern (VOC). The WHO has a working definition for how they classify VOCs. Based on an independent group of experts they determined that preliminary evidence suggested an increased risk of infection for this variant, compared to other VOCs, in almost all provinces in South Africa. There is no current information to suggest symptoms of omicron differ significantly from other variants. Preliminary data from the region indicates an increased rate of hospitalization but this could be linked to an increased number of people being infected and will need to be studied further to determine if this variant will increase the severity of illness.