
“It’s a matter of when and how fast this variant is going to replace other variants,” says Michael Worobey, head of the UA’s Department of Ecology and Evolutionary Biology.
Health experts are warning we are in a race between vaccine distribution and new, more transmissible coronavirus variants.
While most measurements show the pandemic improving in Arizona, two new variants have been discovered here. Both are known to be more contagious.
If these variants establish a foothold in the state, they could prolong the pandemic in Arizona unless people get vaccinated faster. The question is whether we can take advantage of our head start.
“Let’s all hope that we can get vaccination out in front,” said Dr. Joshua LaBaer, director of the Biodesign Institute research center at Arizona State University. “But certainly the variants, there’s risk that they could spread quickly.”
Arizona has been one of the slowest states to vaccinate its residents, according to data from the Centers for Disease Control and Prevention.
In terms of the number of people who have received both vaccine doses, as of Friday, the state ranked 50th out of all states, territories and the District of Columbia — a group of 59 places.
Many health experts believe it’s not a matter of “if,” but “when” a more contagious variant will become the dominant strain.
“It’s best to assume that it’s here at low levels already,” said Michael Worobey, head of the University of Arizona’s Department of Ecology and Evolutionary Biology. “It’s a matter of when and how fast this variant is going to replace other variants in Tucson.”
When the virus travels faster from person to person, this kicks herd immunity further down the road. As the virus spreads faster, the same vaccination rate becomes less effective at getting us there.
The mutations that evolve into new variants are no surprise, said David Engelthaler, head of the infectious-disease branch at Translational Genomics Research Institute, or TGen, an organization that screens for these new variants.
He pointed out that the coronavirus variant the world has been fighting for around a year was once a “new” supercharged variant. These newer ones just happen to be even more supercharged.
One of the new variants detected in Arizona originated in the United Kingdom. Researchers traced it back to a case from Kent, in southeast England, in September. It soon became the dominant strain in the U.K. and then spread around the world.
So far, this U.K. variant, also known as B.1.1.7, has been detected in only a handful of cases in Arizona.
These cases occurred in Maricopa and Pinal counties, said Dr. Theresa Cullen, director of the Pima County Health Department. While this variant has not been detected in Pima County yet, she is on alert.
“The variant doesn’t know that there’s a border,” she said. “And it will cross if and when it wants to.”
Of the few cases of the U.K. variant that have been detected in Arizona, one patient seemed to have contracted it here in the state, while it’s likely the others contracted it while traveling, LaBaer said.
The other new variant here has spread further through the state than the U.K. variant. It originated much closer to home, in Southern California. While it’s also referred to by its place of origin, scientists know it as B.1.427 or B.1.429.
It has not been identified in Pima County, but Engelthaler said TGen is working with Pima County to screen more positive test samples for it.
Other variants from Brazil and South Africa have not been detected in Arizona yet. Both of those variants have a mutation that might reduce the efficacy of the vaccine, LaBaer said. He added that the vaccine still works for these variants, just not as well.
Dr. Joe Gerald, an associate professor with the University of Arizona’s College of Public Health, warns that just because we haven’t detected them yet doesn’t mean they’re not already here.
“We’re not looking very hard,” he said.
About 0.8% of all positive tests have been screened for new variants since the start of the pandemic, Engelthaler said, adding that it’s not much to boast about, but it’s more than the national average.
He wants to reach 5%, but said the state needs to fund the effort.
“We do have the capability here in Arizona to stand up an absolute world-class genomic surveillance system that can be modeled by other states,” he said. “It just will take that commitment at the top level to put the resources into this.”
In the meantime, other researchers are also monitoring wastewater for new variants of the virus.
At the University of Arizona, for example, Worobey is screening samples from Pima County’s Agua Nueva Water Reclamation Facility.
He hasn’t detected the U.K. variant yet, but he said the investigation is still in its preliminary stages.
While known cases of these new variants are still few, that can change fast, just as COVID-19 cases exponentially spiked for the first time nearly a year ago.
Exponential increases are tricky, LaBaer explained. “They don’t look like they’re growing that fast, but if you do the actual math, you can see they’re spreading exponentially and then suddenly they just take off.”
This transition to a new variant won’t happen overnight or within one week, Gerald said. “But in the moment, it will seem like it’s happening very, very rapidly.”
When new variants spread more rapidly, scientists say we need to vaccinate faster because we need a higher percentage of immune people in the population to reach herd immunity.
However, it’s difficult to quantify how many more immune people we need. This is because we still don’t know exactly how much more transmissible the new variants are.
Scientists don’t know, for example, if the Southern California variant is 20% or 50% more transmissible, Engelthaler said. “But suffice it to say, the California lineage, like many others, are becoming more effective at transmission.”
The same goes for the U.K. variant. Early estimates had it around 70% more transmissible, but that has been called into question, Gerald said. It may be less than 70%.
“We still don’t have a very tight, or confident understanding of what that true increase is,” he said.
Even for the variant we’ve been fighting for nearly a year, health experts may have different targets for the number of immune people needed for a community to achieve herd immunity.
Pima County’s chief medical officer, Dr. Francisco Garcia, has said 75% of the population. And on Friday, Cullen, the county’s Health Department director, suggested a target of 80%.
Gerald said that based on the current variant’s R0 value, pronounced “R-naught,” herd immunity could be reached when 60% to 65% of the people are immune.
The R0 is the “base reproduction number.” It tells us how many people a single infected person infects if no one is immune and one is trying to stop the virus from spreading.
For reference, the Rt measures the average number of people an infected person infects as the number of susceptible people changes. Infections slow when the Rt is below 1. The website Epiforecasts.io estimates the current Rt, or reproduction number, in Arizona is 0.81.
Herd immunity will happen when enough people get vaccinated or achieve natural immunity. To rely on natural immunity, however, would be a deadly decision that our health-care system could not absorb.
Lower estimates of natural immunity in Arizona are around 20%, Gerald said, but his is a little higher. He expects 30% to 33% of Arizonans have achieved it.
Using Gerald’s estimates, we would need to vaccinate 30% to 35% of the population to reach herd immunity while fighting the current variant.
When we are up against a new, more transmissible variant we may need to vaccinate 50% of the population, he said.
Arizona is nowhere near these estimated goals. About 1.6% of the population in Arizona has been fully vaccinated statewide, according to CDC data, as of Friday. For example, Cullen said the county may need 1.5 million doses, depending on the target for herd immunity. As of Friday, the county had administered 139,411 doses.
A spokeswoman for the Arizona Department of Health Services said in an email on Friday that the state has been ramping up vaccination efforts but needs more doses from the federal government.
“The belief is the quicker we get people vaccinated, the less COVID we have in the community. … And so we have decreased ability for a variant to take what we might call a foothold,” Cullen said. “So that is the race.”
The best way to reach herd immunity and combat new variants is to “turn up the spigot,” she said. “Get more vaccine available into the community.”
COVID-19 vaccination clinic, retirement community

Otilia Aragon, a resident of The Fountains at La Cholla retirement community, reaches out to touch the face of her daughter Melinda Aragon-Morales, a pharmacist with CVS, who administered the Moderna vaccine to her mother during a Coronavirus (COVID-19) vaccination clinic at The Inn At The Fountains, 5830 N Fountains Ave., on Feb. 9, 2021. "I was really excited," Morales said about administering the vaccine to her mother, "especially in this kind of setting where we haven’t been able to see [family] in a long time." Morales had not seen her mother in several months due to the ongoing pandemic. The clinic is the first of two days where the 585 residents and staff at the retirement community will receive vaccinations for COVID-19.
COVID-19 vaccinations, University of Arizona Mall

People are directed into the line at the University of Arizona's COVID-19 drive-thru vaccination facilities on the UA Mall in Tucson, Ariz., February 5, 2021.
COVID-19, clinic, TCC

The line wends though the parking lots and along the southeastern doors and windows outside the Tucson Convention Center as hundreds wait in line for hours to get the first shot of the COVID-19 vaccine, Tucson, Ariz., February 4, 2021. The age cut off for vaccination was lowered to 70 years of age.
COVID-19 vaccinations, PIma County, Hacienda at the Canyon

Resident Victor Braun laughs with a CVS Pharmacy health care worker after getting his first dose of the Moderna COVID vaccine at Hacienda at the Canyon, Tucson, Ariz., January 27, 2021. The facility's residents and staff were part of a two day vaccination program in conjunction with CVS Pharmacy and monitored by the in-house personnel from TMCOne clinic.
COVID-19 vaccinations, PIma County, Hacienda at the Canyon

A health care worker with CVS Pharmacy preloads a syringe with the first dose of the Moderna COVID vaccine at Hacienda at the Canyon, Tucson, Ariz., January 27, 2021. The facility's residents and staff were part of a two day vaccination program in conjunction with CVS and monitored by the in-house personnel from TMCOne clinic.
COVID-19 vaccinations, PIma County, Hacienda at the Canyon

Gordon Starr quickly gets his first dose of the Moderna COVID vaccine at Hacienda at the Canyon, Tucson, Ariz., January 27, 2021. Starr was among the facility's residents and staff taking part in a two day vaccination program in conjunction with CVS Pharmacy and monitored by the in-house personnel from TMCOne clinic.
COVID-19 vaccinations, PIma County, Hacienda at the Canyon

Nurse Jose Cruz helps member Nelda Clark get her next appointment photographed and stored in her phone after she got her first dose of the Moderna COVID vaccine at Hacienda at the Canyon, Tucson, Ariz., January 27, 2021. The facility's residents and staff were part of a two day vaccination program in conjunction with CVS Pharmacy and monitored by the in-house personnel from TMCOne clinic.
COVID-19 vaccinations, PIma County, Hacienda at the Canyon

James Sugg gets his first dose of the Moderna COVID vaccine at Hacienda at the Canyon, Tucson, Ariz., January 27, 2021. Shannon Ruedlinger, executive director of the facility said that 250 doses were scheduled to be administered to staff and residents there during their two day vaccination program.
COVID-19 vaccinations, PIma County, Hacienda at the Canyon

Member Terrence Carden get his first dose of the Moderna COVID vaccine on the second day of a two program at Hacienda at the Canyon, Tucson, Ariz., January 27, 2021. Shannon Ruedlinger, executive director of the facility said that 250 doses were scheduled to be administered to staff and residents there during their two day vaccination program.
COVID-19 vaccinations, PIma County, Hacienda at the Canyon

Constance Jill Hofer gets her first dose of the Moderna COVID vaccine at Hacienda at the Canyon, Tucson, Ariz., January 27, 2021. Shannon Ruedlinger, executive director of the facility said that 250 doses were scheduled to be administered to staff and residents there during their two day vaccination program. Vaccinations were administered in conjunction with CVS and members monitored by the facility's in-house TMCOne nurses.
COVID-19 vaccinations, PIma County, Hacienda at the Canyon

Right now, Pima County is in Phase 1B of its vaccination plan and is inoculating people 70 and older, and law enforcement, education and child care providers.
COVID-19 vaccinations, Pima County

Clifford Daigler, registered nurse, receives a Pfizer COVID-19 vaccine at Tucson Medical Center, 5301 E. Grant Rd., in Tucson, Ariz. on Dec. 17, 2020. Banner-University Medical Center and Tucson Medical Center began administering Pfizer’s COVID-19 vaccines to healthcare workers in Pima County. TMC administered 1,100 total vaccines between their two clinic sites in the first day of vaccinations, said Claudia Koreny, director of pharmacy for TMC.
COVID-19 vaccinations, Pima County

Needles containing the Moderna vaccine in the Tucson Medical Center drive-thru tent at, on Jan. 5, 2021.
COVID-19 vaccinations, Pima County

Ann Boice receives the Coronavirus (COVID-19) vaccine during the administration vaccination to members of the public who meet the 1B priority eligibility of at Tucson Medical Center's Marshal Center, on Jan. 15, 2021.
COVID-19 vaccinations, Pima County

Annie Waits, a volunteer nurse and vaccinator, administers the Moderna vaccine to a patient in the drive-thru program at the Tucson Medical Center, on Jan. 5, 2021.
COVID-19 vaccinations, Pima County

Steve Patalsky, left, associate director of pediatric bone-marrow transplant, goes over information about the COVID-19 vaccine with Sayea Jenabzadeh, nurse anesthetist, inside the COVID-19 vaccine observation stage at Banner-University Medicine North, 3838 N. Campbell Ave., in Tucson, Ariz. on Dec. 17, 2020. The first round of Pfizer's COVID-19 vaccines were given to healthcare workers at Banner-University Medical Center and Tucson Medical Center.
COVID-19 vaccinations, Pima County

Amy Lopez, left, registered nurse in peri-operative service, and her husband Dr. Mike Lopez, anesthesiologist, talk while waiting for their 15 minutes observation period after receiving their COVID-19 vaccine at Tucson Medical Center, 5301 E. Grant Rd., in Tucson, Ariz. on Dec. 17, 2020. The first round of Pfizer's COVID-19 vaccines are given in Pima County to healthcare workers at Banner-University Medical Center and Tucson Medical Center. "It felt like a normal shot," said Amy Lopez. When asked if they were nervous, Dr. Mike Lopez answered "I was ready to be patient one."
COVID-19 vaccinations, Pima County

Samantha Penn, pharmacist, waits in line with other healthcare workers while people get checked-in for their COVID-19 vaccination appointments at Tucson Medical Center, 5301 E. Grant Rd., in Tucson, Ariz. on Dec. 17, 2020.
COVID-19 vaccinations, Pima County

After receiving the second Pfizer COVID-19 vaccine in Pima County, Melissa Zukowski, medical director of emergency department at Banner-University Medicine Tucson, gives a thumbs-ups to her daughter Sophia Smallwood, left, at Banner-University Medicine North, 3838 N. Campbell Ave., in Tucson, Ariz. on Dec. 17, 2020.
COVID-19 vaccinations, Pima County

Leticia Riesgo, a City of Tucson employee, helps check people into the vaccination clinic for Phase 1B.1.b Prioritized Essential Workers at the Tucson Convention Center, on Jan. 21, 2021. The TCC clinic administered 686 out of a projected 600 vaccines on Jan. 20. They were over 300 vaccinations at midday on Jan. 21.
COVID-19 vaccinations, Pima County

A person walks past a sign for the vaccination clinic for Phase 1B.1.b Prioritized Essential Workers at the Tucson Convention Center, on Jan. 21, 2021.
COVID-19 vaccinations, Pima County

Iris Delfakis, oncology nurse navigator for the Arizona Cancer Center, looks to other nurses as she waits to receive a Pfizer COVID-19 vaccine from nurse Cristina Torres.
at Banner-University Medicine North, 3838 N. Campbell Ave., in Tucson, Ariz. on Dec. 17, 2020. The first round of Pfizer’s COVID-19 vaccines are given in Pima County went to healthcare workers at Banner-University Medical Center and Tucson Medical Center.
COVID-19 vaccinations, Pima County

Tucson Police Officer Roman Acosta is administered the Moderna vaccine at a Coronavirus (COVID-19) vaccine clinic at the Tucson Convention Center located at 260 S. Church Ave., on Jan. 15, 2021.
COVID-19 vaccinations, Pima County

Tal Caspi, a volunteer, answers questions for members of the public before they receive their first vaccine shot for the coronavirus at the Kino Sports Complex, 2500 E. Ajo Way in Tucson, Ariz., on January 18, 2021. Members of the public who fall into the Phase 1B group are eligible for the vaccine at this time. Phase 1B includes people over 75 years old, educators and first responders.
COVID-19 vaccinations, Pima County

Tom Woythal, 85, and his wife, Elizabeth, 82, wait for their opportunity to receive a vaccination shot for the coronavirus at the Kino Sports Complex, 2500 E. Ajo Way in Tucson, Ariz., on January 18, 2021. Woythal says he had been waiting 55 minutes but was happy to wait. Members of the public who fall into the Phase 1B group are eligible for the vaccine at this time. Phase 1B includes people over 75 years old, educators and first responders.
COVID-19 vaccinations, Pima County

A patient looks over paperwork while waiting 15 minutes after receiving the Coronavirus (COVID-19) vaccine at Tucson Medical Center's Marshal Center, on Jan. 15, 2021.
COVID-19 vaccinations, Pima County

Tucson Police Department Chief Chris Magnus receives the Moderna vaccine at a Coronavirus (COVID-19) vaccine clinic at the Tucson Convention Center located at 260 S. Church Ave., on Jan. 15, 2021.
COVID-19 vaccinations, Pima County

People wait in the to be given the Coronavirus (COVID-19) vaccine as members of the public who meet the 1B priority eligibility are now being allowed to receive the vaccination at Tucson Medical Center's Marshal Center, on Jan. 15, 2021.
COVID-19 vaccinations, Pima County

People eligible for the 1B phase of Coronavirus (COVID-19) vaccination stand in line outside the Tucson Medical Center's Marshal Center to receive the shot, on Jan. 15, 2021.
COVID-19 vaccinations, Pima County

A pharmacist prepares a Coronavirus (COVID-19) vaccine to be administered to members of the public who meet the 1B priority eligibility of at Tucson Medical Center's Marshal Center, on Jan. 15, 2021.
COVID-19 vaccinations, Pima County

Sgt. Michael Moseley receives the Coronavirus (COVID-19) vaccine during the administration of the vaccination to members of the public who meet the 1B priority eligibility of at Tucson Medical Center's Marshal Center, on Jan. 15, 2021.
COVID-19 vaccinations, Pima County

People eligible for the 1B phase of Coronavirus (COVID-19) vaccination stand in line outside the Tucson Medical Center's Marshal Center to receive the shot, on Jan. 15, 2021.
COVID-19 vaccinations, Pima County

Pharmacists prepare Coronavirus (COVID-19) vaccinations to be administered to members of the public who meet the 1B priority eligibility of at Tucson Medical Center's Marshal Center, on Jan. 15, 2021.
COVID-19 vaccinations, Pima County

Mike Collier, a volunteer doctor with the Medical Reserve Corps, administers a Coronavirus (COVID-19) vaccine while working his shift in the drive-thru vaccination program at the Tucson Medical Center, on Jan. 8, 2021.
COVID-19 vaccinations, Pima County

“We thought this would be a more efficient and timely process,” says Arizona AARP director Dana Kennedy. “Did they overpromise?”
COVID-19 vaccinations, Pima County

Pharmacist Keith Boesen (right) drops off needles containing the Coronavirus (COVID-19) vaccine at the station of Mike Collier (left), a volunteer doctor with the Medical Reserve Corps, during the drive-thru vaccination program at the Tucson Medical Center, on Jan. 8, 2021.
Contact reporter Alex Devoid at adevoid@tucson.com or 573-4417.