Health officials less confident in COVID vaccine efficacy with rise of Delta variant

Public health confidence in the efficacy of the COVID-19 vaccine appears to be waning as officials warn of enhanced danger — even for vaccinated individuals — from the "Delta variant" of the SARS-Cov-2 virus.

For most of the past year officials have claimed that vaccinations are the only viable path back to normalcy and away from lockdowns and other aggressive mitigation measures. "Look at the folks in your community who have gotten vaccinated and are getting back to living their lives — their full lives," President Joe Biden said at a May press conference, arguing that the vaccine was "going to help them and their loved ones be safe, get our businesses open again, and get us back to normal."

The rollout of the vaccines starting last year and continuing throughout the spring and summer of this year has been hailed as the driving force behind the reopening of the economy and the ending of masking mandates and similar restrictions. 

Yet over the past week the tone from public officials has grown increasingly grim, with leaders now appearing to doubt that the vaccine is sufficient to forestall COVID transmission and potential catastrophe due to the rise of the Delta variant.

An internal government document published Friday morning in The Washington Post stated clearly that vaccinated individuals can still transmit the Delta variant, creating new alarm among medical professionals. The document also stated that the vaccine appeared to provide less protection to the elderly, nursing home residents and those with compromised immune systems than previously thought.

The document urged public health officials to change their messaging about vaccines, saying they are still the best way to prevent getting the most serious symptoms while acknowledging the shots alone may not stop the spread of the virus and that vaccinated people are going to see more breakthrough infections.

“Vaccines  prevent  >90%  of severe  disease, but  may  be less  effective  at  preventing infection  or transmission,” the memo stated. “Therefore, more breakthrough  and more community spread despite vaccination.”

You can read the document here.

A marked shift was seen this week from the U.S. Centers for Disease Control and Prevention, which reversed its earlier masking guidance and claimed that fully vaccinated individuals should wear masks indoors in areas with high COVID transmission. 

The Delta variant "behaves uniquely differently from past strains of the virus that cause COVID-19," CDC Director Rochelle Walensky said at a press conference this week. 

"Information on the Delta variant from several states and other countries indicate that in rare occasions, some vaccinated people infected with the Delta variant after vaccination may be contagious and spread the virus to others," she claimed. "This new science is worrisome and unfortunately warrants an update to our recommendations."

White House coronavirus expert Dr. Anthony Fauci signaled a similar shift during an interview with NPR when he called the Delta variant "a different virus."

The Delta variant "is much more capable of transmitting from people to people," Fauci claimed, stating that when even fully vaccinated people contract the virus "they are capable of transmitting the infection to someone else."

The shift from strong confidence in the vaccine to the masking of fully vaccinated individuals comes after several weeks of steadily rising COVID-19 cases throughout the United States. Experts have feared that the Delta variant could cause a surge in hospitalizations and deaths, leading to catastrophic scenarios of the kinds hypothesized at the outset of the pandemic last year. 

Left uncertain amid the revised recommendations is at what point, if ever, it will be safe for vaccinated individuals to go maskless. Both Fauci and Wallensky have acknowledged that infections in vaccinated individuals are "rare," and both have continued to argue strongly that vaccines are effective at fighting the virus. The disconnect between that confidence and the new guidance has rendered the new directive somewhat opaque in its reasoning. 

Fauci's office did not comment on the doctor's thinking on the matter. The CDC, meanwhile, declined to comment beyond referring to unspecified research it says is guiding its decisions. 

"CDC bases its guidance on the latest science and will update its guidance accordingly as the science warrants," agency spokesman Tom Skinner said via email.

The new guidance, meanwhile, has received pushback, both from Republican opponents of the Biden administration and others. 

Missouri Sen. Josh Hawley said on Tuesday that the new guidance "sends exactly the wrong message: that no matter what you do, you will be required to wear a mask — indefinitely."

Arizona Republic columnist Elvia Davis, meanwhile, wrote this week that the new guidance "sends a confusing message over the effectiveness of the vaccine."

"[T]he CDC, the ultimate scientific arbiter in public health, is confusing the heck out of everyone," she wrote, "and angering people like me who supported and advocated for severe lockdowns and strict mask mandates."

And George Washington University Professor of Medicine Jonathan Reiner called the CDC's new guidance rollout "astonishingly bad."

"Instead of clearly articulating the problem which is 80 million adults have chosen not to get vaccinated and they are largely also unmasked, CDC suggests that the problem is rare transmission from vaxed to unvaxed people," he wrote. "This is so wrong."