Delta COVID-19 Labeled Variant of Concern by CDC

Two doses of COVID-19 vaccines seem to be able to somewhat nullify the effects of the highly transmissible Delta variant, but fewer than 50% of adults in the United States have gotten two doses.

Two doses of COVID-19 vaccines appear to be highly effective against B.1.617.2 COVID-19—or the Delta variant—and that’s the good news. However, the number of people in the United States who’ve gotten two doses seems to have stalled in recent weeks, and currently stands at 43.9%, according to the Centers for Disease Control and Prevention (CDC).

That’s one of the reasons why the CDC yesterday labeled B.1.617.2 a variant of concern. It had previously been a “variant of interest.” The CDC defines a “variant of concern,” as “a variant for which there is evidence of an increase in transmissibility, more severe disease (e.g., increased hospitalizations or deaths), significant reduction in neutralization by antibodies generated during previous infection or vaccination, reduced effectiveness of treatments or vaccines, or diagnostic detection failures.”

Just last week, both the CDC and the Biden administration expressed their concerns about the variant and reinforced the need for COVID-19 vaccination. “This variant is now identified to be more transmissible than even other hyper transmissible variants like the one from the UK,” CDC Director Rochelle Walensky, MD, said in an interview last week. “We also know that while our vaccines do work against it, they don’t have as much buffer in terms of protection as some of the other wild type strains. So, the concern is not just the more transmissibility—and we have seen more virus in the UK where this variant has also emerged—if we have this other variant circulating here it may lead to a more virulent variant such that our vaccines wouldn’t be able to work.”

The Delta variant bolsters the argument against vaccine hesitancy, a hesitancy found even among health care professionals in hospitals. Major hospitals such as Penn Medicine: University of Pennsylvania Health System, Johns Hopkins Hospital, and New York-Presbyterian Columbia University Medical Center have made working at those institutions contingent on employees getting the COVID-19 vaccine.

Paul Sax, MD, the clinical director of the infectious disease clinic at Brigham and Women’s Hospital, tells Infection Control Today® (ICT®) that these hospitals are “major institutions” and their action might pave the way for more hospitals to mandate that employees get vaccinated.

“I was pleasantly surprised that some of the hospitals have taken the plunge.” (He said that Brigham and Women’s hospital, part of a health care system, has not as yet made that decision.)

That hardline stance might become more prevalent. Kevin Kavanagh, MD, a member of Infection Control Today®’s Editorial Advisory Board, wrote an opinion piece on the ICT® website on April 22 with the not-too-subtle headline: “Viewpoint: Health Care Professionals—Get Vaccinated or Get Out.” In it, Kavanagh wrote that “if you work in a health care facility, you need to be vaccinated against SARS-CoV-2. If you choose not to become vaccinated, then you should choose not to be working in a health care setting.”

Sax feels the same way. "You know, if you don’t want to do this, and you don’t have a medical reason not to do it—because there are people who have a medical reason not to do it—then I suggest really that you find another job."

Rather than finding another job, some vaccine hesitant health care workers have decided to fight back instead. Last week Houston Methodist Hospital suspended 178 employees who refused to get vaccinated for two weeks, and 117 of those employees sued the hospital. Last Saturday, U.S. District Judge Lynn Hughes dismissed that lawsuit in a 5-page ruling.

Sax tells ICT® that he wants “people to remember this is a highly contagious virus getting more so all the time…. One of the most horrible scenarios you could have is to be a [health care provider] with asymptomatic or mild COVID-19 and end up transmitting the virus to a vulnerable person who perhaps was vaccinated, but has got a weakened immune system and doesn’t respond to the vaccine. There are all kinds of scenarios where people with infection can transmit the virus to vulnerable people in the health care setting and reducing that risk as much as possible is really key.”

The Delta variant, which was first identified in India, ravaged that country this year. India reported over 300,000 cases on 1 day alone in May. At one point, the country was losing 3000 people daily to COVID-19.

Since then, the variant has continued to make its way west with it now the dominant strain in the United Kingdom, accounting for over 90% of COVID-19 cases in that country. Thus far, the COVID-19 vaccines appear to be effective against Delta. In a study done by Public Health England and published in the journal BMJ, the Pfizer vaccine was 88% effective against symptomatic disease from the variant 2 weeks after the second dose, compared to 93% effectiveness against the B.1.1.7 (UK) variant. For the Astra Zeneca vaccine, it was 60% effective against symptomatic disease from the B.1.617.2 variant compared to 66% effectiveness against the B.1.1.7 variant.

The Public Health England study also found that two doses of Pfizer/BioNTech vaccine is 96% effective against hospitalization. Investigators with Public Health Scotland on Monday also concluded that two doses of the vaccines should be quite effective against the Delta variant. Their findings were published in the Lancet.

The BMJ study quotes Neil Ferguson, director of the Medical Research Council’s Centre for Global Infectious at Imperial College London, saying: “It’s well within the possibility that we could see another third wave, at least comparable in terms of hospitalizations, maybe not as severe as the second wave. Almost certainly I think that deaths probably will be lower. The vaccines are having a highly protective effect, and cases in hospital are milder, but still it could be quite worrying. There is a lot of uncertainty.”