'Pandemic Is Far from Over': Largest US Nurses Union Urges CDC to Reinstate Federal Mask Mandate

Declaring Covid-19 vaccines "not enough by themselves to combat the pandemic," the nation's largest union of registered nurses on Tuesday called on the Centers for Disease Control and Prevention to reinstate the federal mask mandate.

"The Covid-19 pandemic is far from over," the union said in its letter (pdf) to CDC director Rochelle Walensky.

Signed by NNU executive director Bonnie Castillo, the letter points to a number of factors, including the emergence of concerning variants, to warrant updated guidance, which currently states that fully vaccinated people no longer need to wear masks or abide by physical distancing requirements.

Among the issues is an upward trend in Covid-19 cases.

"In the United States, the CDC reports a 16.0% increase in daily new cases over the previous week," the letter states. "More than 40 states have seen an increase in daily new cases over the previous two weeks, and more than 25 states have seen an increase in hospitalizations." Beyond national borders, cases are also rising in scores of countries.

The emergence of the highly transmissible Delta variant is an additional concern. "Preliminary data from Israel and the United Kingdom indicate that Covid-19 vaccines may be less effective against the Delta variant than other variants," the letter states.

The union calls the rise in U.S. cases unsurprising as it followed "the rapid reopening of many states and the removal of public health measures, including the CDC's May 13 guidance update that told vaccinated individuals they no longer needed to wear masks, observe physical distancing, avoid crowds, or get tested or isolate after an exposure, within only a few exceptions." That guidance, the letter continues, "failed to account for the possibility--which preliminary data from the United Kingdom and Israel now indicates is likely--of infection and transmission of the virus, especially variants of concern, by fully vaccinated individuals."

The dropping of the mask mandate--even as the "threat of this virus remains very real"--also put at risk "medically vulnerable patients, children, and infants who cannot be vaccinated, and immunocompromised individuals for whom vaccines may be less effective," the union says.

In light of those factors, "NNU strongly urges the CDC to reinstate universal masking, irrespective of vaccination status, to help reduce the spread of the virus, especially from infected individuals who do not have any symptoms," wrote Castillo, who pointed to research indicating as many as a half of all transmission events stem from cases that have no symptoms.

NNU is also calling on the CDC to "fully recognize" aerosol transmission of the virus, with updated guidance "including prioritizing engineering controls, such as ventilation and air filtration, and respiratory protection and revoking crisis standards for PPE" that allow for reuse of single-use personal protective equipment and thus put nurses and other workers at risk.

Better tracking of infections among healthcare workers is needed, Castillo wrote, as is tracking of so-called "break through" infections. Such infections should be documented whenever possible, not just when they result in hospitalization or death. This data "is critical to determining vaccine effectiveness and duration of vaccine protection or whether emerging SARS-CoV-2 variants are becoming more resistant to vaccines."

The new letter came two weeks after the World Health Organization said fully vaccinated people should still wear masks and practice social distancing.

"This still continues to be extremely important, even if you are vaccinated, when you have a community transmission ongoing... in general, where you have a high level of continuous community transmission," said Dr. Mariangela Simao, WHO's assistant director-general of Access to Medicines and Health Products. "So, people cannot feel safe just because they had the two doses. They still need to protect themselves."