So, I keep hearing about the Delta variant… What does that mean?  What do I need to do?

As expected, the COVID virus has mutated, and we now have multiple variants of the virus all over the world.  The WHO labels the variants using the Greek alphabet (alpha, beta, gamma, delta, etc…) as a practical way to track them across the globe.  Some of the concerns about variants are:

  • Are the new strains more transmissible? That is, do they spread from person to person easier?
  • Will our COVID tests detect the new strains?
  • Will our current medications be effective for patients who are infected with the new strains?
  • Will our vaccines still protect us from these new strains?
  • Will these new strains cause more severe infections with more hospitalizations and deaths?
  • Will people who have already had COVID be vulnerable to these new strains (immune escape)?

We classify variants into 3 categories: Variants of Interest, Variants of Concern, and Variants of High Consequence.  In the US, we are currently monitoring 6 Variants of Interest (2 of these were Variants of Concern that have been downgraded).   We are also monitoring 4 Variants of Concern.  The Delta variant is in this category.  These 4 strains have increased transmission rates (up to 50% increase), some are much less susceptible to monoclonal antibodies, and there is concern about the potential increase in disease severity with the Alpha strain.  Thankfully, there are no Variants of High Consequence identified in the world right now.




The Delta variant is the cause of most of the recent US cases of COVID (estimated 83%). Infections happen in only a small proportion of people who are fully vaccinated, even with the Delta variant.  However, preliminary evidence suggests that fully vaccinated people who become infected with the Delta variant can spread it to others.  Therefore, the CDC updated their recommendations on Tuesday (July 27) for fully immunized individuals in communities with substantial or high transmission rates to wear masks in public, indoor settings.  Vermont has no areas of substantial or high transmission right now.  Thankfully, almost all of New England has low to moderate transmission rates.  We have, however, seen a slight increase of positive cases in Vermont and across New England since the end of June 2021.  We will continue to monitor closely.


*Our vaccines are still effective to prevent severe illness and hospitalization. More than 97% of people hospitalized for COVID are unvaccinated. 

*Viruses mutate and variants emerge.  Scientists are studying COVID variants around the world.

*The Delta variant is the most common strain in the US right now and seems to be much more contagious than our previous strains.

*We do not know if vaccine boosters will be needed.  The CDC, FDA, and NIH are reviewing the data carefully and will make recommendations.