Summary: The Delta variant currently accounts for the vast majority of new COVID-19 cases in the United States. It has posed an unprecedented challenge in combating this pandemic for the following reasons:
- Over 225% more transmissible than the original variant
- Over 1,000x the viral load in infected individuals
- Increased amount of mild to moderate infections in vaccinated individuals transmissible to others
In response to the growing spread of the Delta variant, the CDC has updated its guidance for vaccinated individuals on July 27, 2021 with the following.
- In areas of substantial or high risk all individuals should be masked indoors regardless of vaccination status
- Vaccinated individuals who have come in close contact with a confirmed or suspected case of COVID-19 should test 3 to 5 days after exposure with a PCR test and use a mask when in public for 14 days
As the transmission rates of the Delta variant of COVID-19 in the United States are increasing, we understand that there is growing concern on how the variant will affect workplace safety recommendations. We at Eden continue to evaluate the evidence as it evolves and at this time, it is recommended to implement mask use in both vaccinated and unvaccinated individuals indoors. CDC guidance has been updated to reflect the increasing risk of transmission with symptomatic vaccinated individuals.
At this time, they recommend vaccinated individuals use masks indoors in areas with substantial transmission or higher due to the delta variant. We additionally recommend at this time, in areas of lower transmission, implementing indoor mask use for vaccinated individuals in high occupancy, congested, or public-facing workplaces. Social distancing for all individuals is recommended in all workplaces as a minimum risk mitigation measure if masking recommendations are not in place.
The following are some of the commonly asked questions regarding the Delta variant and responses you can use when discussing risk at your workplace.
What is the Delta Variant?
The B.1.617 lineage known as Delta, was first identified in India as a variant of concern responsible for a surge of cases. It shares mutations with both the alpha (B.1.1.7) and beta variants (B.1.351) identified in the UK and South Africa respectively. These mutations allow the Delta variant to be more transmissible and evade some of the natural and vaccine-induced immune responses. It was quickly noted to be a variant of concern by the World Health Organization as the variant overtook the predominant alpha variant in both UK and India. In the United States, the Delta variant has quickly spread in the past few weeks to become the dominant variant, accounting for 51 percent of COVID-19 cases as of the time of this writing.
What makes the Delta variant so concerning?
This variant is significantly more transmissible than the original variant and better able to evade our immune response. The alpha variant was also more transmissible and was responsible for 3rd and 4th waves throughout the United States this past spring. The Delta variant is estimated to be 225% percent more transmissible than the original variant. Additionally, partial vaccination does not significantly reduce risk, as was previously seen with the alpha variant.
This means that lower-risk activities are now much higher risk, as it is much easier to become infected in shorter periods of time. Greater than 1,000 times higher viral loads are seen in infected individuals with this variant when compared to the original variant. There may also be an increased risk of hospitalizations and severe illness in unvaccinated individuals, but more data is needed to better understand if the variant is truly more pathogenic than other variants. In vaccinated individuals, this means a likely increased risk of mild to moderate breakthrough infections. For vaccinated individuals, the infections tend to be asymptomatic or mild, but for those at higher risk, such as those over the age of 65, immunocompromised individuals, or those with comorbidities, there may be a higher risk for more serious illness.
Are the symptoms from the Delta variant the same as other variants?
Another important difference with the Delta variant is the symptoms that are most commonly reported with infection. The most common symptoms cannot be differentiated from a common cold: sneezing, coughing, sore throat, runny nose, headache. As viruses that cause common colds are also increasing in circulation, and symptoms like fever and loss of sense of smell or taste are more often regarded as necessary for a diagnosis of COVID-19, these symptoms are often dismissed or attributed to seasonal allergies.
It’s important to discuss with all employees the importance of reporting all symptoms, regardless of severity, and staying home until those symptoms have been evaluated by a healthcare provider and/or the employee has tested negative with a PCR or nucleic acid amplification test.
What is the best way to keep my workplace safe from COVID-19?
It’s important to remember that risk reduction is additive. In areas where community transmission of the Delta variant is high and vaccination rates are low, even a fully vaccinated workplace should consider mask use as an additional precaution until the surge has receded.
As effective as vaccines are in preventing severe illness and death from emerging variants such as Delta, additional measures are still critically important to detect cases and prevent transmission in the workplace. In addition to achieving the highest rates of vaccination at your workplace as possible, the following should also be in place:
- Improved indoor air ventilation/quality
- Post-travel testing and quarantine as per CDC recommendations
- Symptom screening of all employees
- Contact tracing of workplace infections
- High quality mask use: The World Health Organization and the Los Angeles county health department have both recommended mask use indoors for fully vaccinated individuals given the rates of breakthrough infections internationally in areas heavily affected by the Delta variant and activity in LA county. To mitigate the risk of transmission from breakthrough cases in vaccinated individuals in addition to unvaccinated individuals, a review of masking policies is recommended for the following:
- For all workplaces, social distancing is highly recommended if vaccinated individuals are unmasked.
- For mixed vaccination status workplaces, especially in areas where virus prevalence is above 5 percent, mask use is recommended for all individuals.
- For public-facing workplaces, mask use is recommended for all individuals at all times.
- For highly concentrated or congested workspaces or gathering areas, mask use is recommended for all individuals regardless of vaccination status.
- Avoid medium-to-large-sized indoor gatherings, even with fully vaccinated groups, whenever possible.
Is it possible for infected vaccinated people to infect others?
Yes, vaccinated individuals infected with the Delta variant can still transmit the virus to others. Transmission can occur within the first 48 hours prior to developing symptoms and within the first 10 days of infection. For those that develop asymptomatic infection (those who never develop symptoms), it is possible that they are still contagious but the data on these types of infections is very limited. Fully vaccinated people are still likely to be contagious for a shorter period of time than unvaccinated individuals and significantly less likely to develop severe illness that results in hospitalization or death from COVID-19.
If I’m fully vaccinated, can I get infected from another vaccinated individual if they have COVID-19?
Yes, there is limited documented evidence of transmission from infected individuals fully vaccinated with Pfizer, Moderna, and AstraZeneca vaccines, to other fully vaccinated individuals after unmasked close contact, whether indoors or outdoors. The Pfizer, Moderna, and AstraZeneca vaccines are estimated to have between 64 to 88 percent efficacy against the Delta variant, so the overall risk is still significantly lower for vaccinated individuals than unvaccinated individuals. Against severe illness and death, all of the vaccines continue to have very high efficacy and remain the most important measure, along with mask use, for individual and community protection.
Should vaccinated individuals with close contact exposure to COVID-19 still quarantine?
If a vaccinated individual has a close contact exposure with a confirmed or suspected case of COVID-19, the current recommendation is to use a mask when outside of their home for 14 days and undergo a PCR test 3 to5 days after the last exposure. Fully vaccinated people who live in a household with someone who is immunosuppressed, at increased risk of severe disease, or unvaccinated (including children <12 years of age) could also consider masking at home for 14 days following a known exposure. They should closely monitor for symptoms during the 14-day period and, should any symptoms occur, isolate immediately and obtain a PCR test. The CDC has updated these recommendations here.
Will booster shots of the COVID-19 vaccine be necessary?
Pfizer/BioNTech released pre-publication data on July 28, 2021, demonstrating a decrease in efficacy against hospitalization for its vaccine in the first 4 to 6 months, from 100 to 84 percent on average. Given this modest waning in efficacy, Pfizer recommends a third dose for its COVID-19 vaccine series, but continued studies are needed to determine optimal and appropriate timing. Pfizer plans to formally submit data to the Federal Drug Administration this August. Trials are also underway from Moderna, and Johnson and Johnson to determine the need for a third or second dose in their series for sustained immunity, or a potential booster specific to Delta and other variants of concern.
There is an adequate amount of evidence that certain immunocompromised individuals may need a third or second dose, as they did not mount a sufficient response to the vaccine with the initial series. This includes certain older adults, solid organ transplant recipients, and those on certain immunosuppressive medications. We expect those recommendations to be updated in the coming weeks.
Authored by Talia Poy, AGNP-C
This information is based on current resources available and is subject to change. This document and its contents are provided for informational purposes only, and not intended to be, and should not be understood or treated as, a substitute for professional medical advice around COVID-19, its risks or symptoms, or to take the place of any local, state and national laws and guidelines around COVID-19. Always seek the advice of a physician or other qualified health provider with any questions you may have regarding a medical condition.
