The Delta Variant

The Delta Variant

West Virginia is entering into the next chapter of the COVID-19 pandemic – one that is fueled by the Delta variant. We should consider the Delta variant a different kind of virus than the COVID-19 viruses we have seen to date.

Why?

The Delta variant of COVID-19 is much more infectious than any COVID-19 strain we have seen to date. It exists in 1000-times more virus in the airways of infected people than we have seen with other strains. It is reported as contagious as chicken pox, and it has been reported that people walking through air droplets that contain the virus have been infected by the Delta variant of COVID-19.

The Delta variant spreads very quickly person-to-person and in social networks, which accounts for the explosive nature of the rapid growth in new cases and hospitalizations.

This variant started in India, where it devastated the country. India saw an explosive increase in new cases and owing to its poor national vaccination rate, there were many people that were hospitalized and that died. At the peak of Delta variant infection in India, cities ran out of hospital beds and oxygen. Families were asked to supply oxygen to their family members lucky enough to find a hospital bed. While official figures place deaths in India from this variant at 400,000, researchers believe the number may be as high as 3.5 to 5 million people who died.

The characteristic shape of the infectious curve created by the Delta variant is an inverted V. This inverted V curve is characterized by very rapid growth of new cases and hospitalizations to a peak and then a rapid downturn.

What accounts for this?

It is likely the rapidity in which the Delta variant infects so many people so quickly, that eventually there are firewalls – people that are immune to Delta through immunization or recovery from infection – and the Delta variant burns itself out. This is like a fast-moving fire that consumes all the flammable material in a forest and then burns out.

In India, before the Delta variant took hold, 24% of its population showed evidence of past COVID-19 infection by immune antibody detection. Delta variant ravaged India for about 10-12 weeks. After this time, a reassessment was made and about 70% of India’s population then showed evidence for immune function to COVID-19.

That is a startling figure.

As opposed to India, the United Kingdom also was challenged with the Delta variant but did not suffer the same loss of life or great surge in hospitalization. In the U.K., which is heavily vaccinated, the variant created the same inverted V growth curve and rapidly increased new cases. However, with the large number of citizens with vaccination, they did not see a sharp increase in hospitalization and saw virtually no increase in deaths. In addition, their surge lasted only 6-8 weeks, as opposed to the 10-12 weeks of surge in India.

This compelling data suggest that full vaccination is the key to successfully dealing with the Delta variant.

An additional confusion with the Delta variant is its potential to create breakthrough infection for those fully vaccinated.

A case in point is the resort town in Cape Cod, Provincetown, Massachusetts, a very upscale resort beach town that attracted a lot of people to celebrate July 4. Many of these vacationers were fully vaccinated. These people were part of a large cluster outbreak from the Delta variant, which ultimately infected about 1,000 individuals.

The critical finding in this outbreak is that close to 75% of these newly infected vacationers were fully vaccinated and had a breakthrough infection. Moreover, they were found to have an equal concentration of COVID-19 in their nasal swabs as were unvaccinated people.

Some have interpreted this finding as evidence that vaccines don’t help in addressing the Delta variant of COVID-19.

That is false. Very false.

Why?

Of these vacationers, newly infected and fully vaccinated, only four people ended up needing hospitalization and no one died.

This finding is amplified by the discovery that over 90% of people in U.S. hospitals are unvaccinated, over 95% of people in intensive care units are unvaccinated and over 98% of those dying are unvaccinated.

Like we saw in the U.K. with the Delta variant, highly vaccinated populations are protected from hospitalization and death.

Full vaccination provides consistent and effective protection against the most severe consequences of the Delta variant.

While we are concerned about the possibility of fully vaccinated West Virginia residents having more risk of breakthrough infection that could result in infecting others, all the data points show that full vaccination is the solution to saving lives and reducing hospital surge.

That is clear.

Full vaccination by mRNA vaccines (Pfizer and Moderna), and additional layered mitigation strategies, including three- or four-ply masks that are well-fitting around the face, physical distancing, hand washing, cough and sneeze hygiene, as well as being tested for COVID-19 if cold-like symptoms are present is strongly encouraged.

However, by Centers for Disease Control data, masks alone provide a 40-60% reduction in source control (droplets, aerosols), but only a 20-30% increase in personal protection. Thus, layered protection relies on full vaccination as the primary intervention.

This next chapter of COVID-19 with the Delta variant has the potential to test us differently than we have seen before. We need all West Virginians to “run to the fire” and “pull the rope together” by choosing full vaccination and layered mitigation.

In summary:

• The Delta variant is more contagious than other virus strains.
• Unvaccinated people are at the greatest risk for severe illness, hospitalization and death.
• Highly vaccinated populations seem to be protected from hospitalization and death.
• Vaccination is the primary mitigation strategy and can be more effective with additional measures such as well-fitting, multi-ply masks, physical distancing, hand washing, cough and sneeze hygiene and being tested when cold-like symptoms appear. 

We will do best if we approach this together.

Shine bright West Virginia. There are rough waters coming up and many will need a beacon.

Let’s be that light.
 

Clay Marsh, MD
West Virginia COVID-19 Czar
Vice President and Executive Dean, WVU Health Sciences