Delta Variant US: Delta Variant of COVID, or B.1.617.2, will soon be the dominant COVID strain in the US. What does it mean for those who got the COVID vaccine? What does it mean for those who did not get the COVID vaccine?
Delta Variant US
Are The Vaccines Effective?
The UK is a world leader in genomic surveillance and couple that with lots of COVID cases, they were able to do some great analytics in their studies. Thankfully, studies show that the COVID vaccines, which in the UK are the Pfizer and AstraZeneca vaccines, remain effective against the delta variant. As long as people had both shots.
So far, we don’t have data on the J&J and Moderna vaccines, but we should get the data soon. Presumably, the Moderna vaccine will have similar efficacy as Pfizer since they are very similar mRNA vaccines, and they have similar efficacy against COVID in general. Hopefully, the J&J vaccine will have the same efficacy against the delta strain as it does other strains.
What about those who are unvaccinated?
Their risk depends on many factors. You still have the usual risk factors for COVID. Older age. Male. Type A blood. High blood pressure. Obesity. Diabetes. Heart disease. But how does that risk change based on previous COVID strains compared to the delta variant? Based on the limited data so far, this risk is only going up. The delta variant in Scotland doubled the risk of hospitalization for those who contracted COVID.
Delta variant is 60% more transmissible than the alpha variant.
Delta variant COVID cases are doubling every 11 days in the UK. In the US, it’s soaring in the Midwest and southeast. There is a company in California called Helix, and they are conducting nationwide genomic sampling. They found that the proportion of cases caused by Alpha fell from more than 70% in late April to around 42% as of mid-June, with the rise of Delta driving much of the shift.
So far, data from Helix suggest that the Delta variant is spreading faster in US counties where less than 30% of residents have been fully vaccinated, compared to higher vaccinated counties. If you look at the country as a whole, the delta variant made up 10% of COVID cases, and as of the recording of this video, it is already 21%. The numbers have been doubling about every 2 weeks, so it will likely become the dominant strain in a few weeks, especially now that we have lifted restrictions.
According to the CDC, as of June 23, two-thirds of the adult population in the US has received at least one dose of a Covid vaccine; based on recent polls, 20% of American adults say they won’t get vaccinated. The proportion is higher in certain groups – like younger age, those who live in rural areas, and White evangelical Christians.
What The Models Are Predicting?
The most recent models based on the Delta variant being 60% more transmissible along with a predicted 75% of eligible Americans becoming vaccinated means that we’re probably looking at on average 2,000+ deaths per week during the fall and winter. Then you combine that with kids less than 12 who can’t get the vaccine, at least not yet, who will be back in school at that time, and that’s a bad outlook. But based on the model, if 86% of eligible Americans are vaccinated – that might avert over 10,000 deaths by the time you hit December.
Risk of mRNA COVID Vaccines (Pfizer and Moderna)
When we talk about risks with the mRNA vaccines, with Pfizer and Moderna, we know that they can cause some side effects in the first 2 days. That’s the immune system at work for you. And there is a minimal risk of allergic reactions, which are almost never serious. But what about myocarditis, meaning inflammation of the heart muscle? Or pericarditis, inflammation of the sac that covers the heart? Myocarditis and Pericarditis often go together. I dedicated a whole video to this topic, which will be posted on June 25th.
Doctor Mike Hansen, MD
Internal Medicine | Pulmonary Disease | Critical Care Medicine