2/8 In Connecticut, the % of sequenced cases that are the Delta variant (B.1.617.2) decreased in recent weeks. This is probably more of a reflection of noisy data when trying estimate frequencies from a small number of cases vs an actual decline in delta.
3/8 Looking at our neighbors in Massachusetts and New York, delta is 10-20%, so we in Connecticut are probably pretty close to that. My guess is that we'll see a π in delta in the coming weeks to reflect the trends of our neighbors.
4/8 The continuing good news is that COVID-19 cases in CT continue to remain very low, meaning that we are not yet seeing any real impacts of delta locally. Given this, a common question that I am being asked is: "why should we even care about delta?"
5/8 The answer: If delta continues to become more prevalent, it has the ability to make outbreaks among unvaccinated populations a lot worse, furthering the health disparities in our communities. As a result, we may also see an increase in total cases, as seen in the UK.
6/8 For the vaccinated populations, delta is not an immediate threat. However, our vaccines work best when they have less work to do. So if delta increases transmission in our communities, it will provide more opportunities for some vaccines to fail.
7/8 As for any variant, the best way to prevent your vaccination from failing is to increase the vaccination rates in your networks. Please talk to your family and friends about the benefits of vaccines. cdc.gov/coronavirus/20β¦
8/8 This week I'd like to thank our @YaleSPH summer interns, @BilligKendall & @rtobiaskoch, who are learning how to complete our entire process - from sequencing to analysis - and will help lead our partnerships in the Caribbean πππ
2/7 Gamma (P.1) and Delta (B.1.617.2) continue rising in Connecticut, while Alpha (B.1.1.7) and others decline, following national trends (see next tweet).
3/7 Data from outbreak.info shows that in the US πΊπΈ, Delta (B.1.617.2) is π exponentially, while Alpha (B.1.1.7) is on the π. Despite this, COVID-19 cases are still dropping (for now).
2/6 We now have 8 cases of B.1.617.2 (5 shown in the π²) and 2 of B.1.617.1. To my knowledge, none of these are associated with βοΈ. Our phylo π² shows that there are at least 4 independent transmission chains of these viruses, spanning at least 3 counties. Definately one to π
3/6 The π in B.1.1.7 shown in tweet 1 is probably a combination of noisy data with few cases and the emergence of other lineages. The figure π 1 is from TaqPath SGTF data, which is a week ahead of the sequencing shown π, where we don't yet see the sudden π.
2/5 The second case of B.1.617.2 was from the same county as the first case (Fairfield), but they are unrelated (see tree π). Neither cases are known to be linked to international travel.
3/5 B.1.1.7 is still π frequency not because the lineage is rapidly expanding, but because it is dying out slower than the non-B.1.1.7 lineages. So the total number of B.1.1.7 cases π by 87% since late March.
2/7 B.1.617 first reported in India comes in 4 different flavors primarily defined by their spike gene mutations. While the CDC currently recognizes all 4 as VOIs, the B.1.617.2 lineage that we detected importantly does not have the E484Q mutation.
3/7 The B.1.617.2 case was not associated with travel, suggesting that there is some level of local transmission. Though the presence of other highly transmissible variants in CT - like B.1.1.7 - may limit its ability to become established.
2/8 Last week we saw a dip in the probably B.1.1.7 cases determined by TaqPath SGTF results. I showed how the sequencing tracked with the SGTF data, and that the dip was probably a blip...
3/8 That "blip" was confirmed: B.1.1.7 π this week in both the sequencing and TaqPath SGTF data (shown π). While we expect B.1.1.7 to continue this trend until it dominates (like in the UK), the good news is that we are seeing a reduction in both B.1.1.7 and non-B.1.1.7 cases.
2/9 While we continue to see the rapid decline of non-VOCs/VOIs, the competition between B.1.1.7 & B.1.526 is quite interesting, and could have significant public health importance. Currently B.1.1.7 is "winning", though things could rapidly change as more people get vaccinated.
3/9 For the first time we saw B.1.1.7 π from TaqPath data, which could mean that it is slowing down (it has to at some point). Below I also plotted the B.1.1.7 frequency estimates from our sequencing data, which has tracked with TaqPath and importantly still shows B.1.1.7 π