Why thousands of Utahns have missed their second COVID-19 vaccine dose and how it might affect the spread of the virus

The biggest risks of missed doses is that COVID-19 will continue to spread and eventually produce more hazardous variants, Utah doctor says.

(Francisco Kjolseth | The Salt Lake Tribune) Nurse Julia Paas, right, goes over information with Betsy Altschuler as she gets ready to receive her second dose of the COVID-19 vaccine at the Utah Film Studios in Park City on Thursday, March 18, 2021. More than 70,000 Utahns have missed their second dose of vaccine in a two-shot course, state health officials said, a pace that is slightly higher than the national rate.

More than 70,000 Utahns have missed their second dose of coronavirus vaccine in a two-shot course, state health officials said, a pace that is slightly higher than the national rate.

That total is about one in ten Utahns, as of last week, compared to nationwide rate of about 9%, said Tom Hudachko, spokesman for the Utah Department of Health.

The Pfizer and Moderna vaccines — the ones which require two shots given three or four weeks apart, respectively — drop from about 95% effectiveness to about 55% effectiveness if a patient only receives one of the shots, said Kavish Choudhary, senior director of pharmacy for University Health.

“It’s pretty significant,” Choudhary said. “It’s to our benefit to get as much immunity as we possibly can. ... It’s the best for public health.”

Not much is known about all the ways that lessens the vaccine’s protection; other than the overall drop in efficacy, researchers don’t yet know whether — or by how much — missing one shot might shorten the duration of its protection, increase the likelihood of spreading the virus to others, or heighten the risk of serious illness, hospitalizations or death.

“What we do know is that COVID-19 has caused very serious illness and death for a lot of people,” Choudhary said. “If you get COVID-19, you also risk giving it to loved ones who may get very sick. Getting a COVID-19 vaccine is a safer choice.”

But some patients aren’t so sure.

Why are some Utah patients missing a dose?

State health officials are working on a survey to learn why some patients are only getting one dose, Hudachko said.

But several Utah patients who missed, or are considering skipping, their second shots shared their reasoning with The Salt Lake Tribune, and one explanation was by far the most common.

Most of those patients were concerned about the side effects of the vaccine.

Some reported developing serious symptoms following their first shot; two said they experienced allergic reactions so severe that their doctors advised against the second shot.

“My heart went into atrial fibrillation, and I just kept throwing up,” said Brittany Nelson, a 37-year-old from Riverdale. “I was dizzy and it was very scary.”

Nelson said she received allergy medications but still is experiencing some throat swelling and chest pain. She never had experienced an allergic reaction to a vaccine before, she said, and her doctor said it would be safest to sit out the second shot, in accordance with guidance from the U.S. Centers for Disease Control and Prevention.

Serious allergic reactions appear to be extremely rare. One study has found allergic reactions — ranging from a rash to breathing problems — occurred in about 2% of patients who received the two-dose vaccines. Serious or anaphylactic reactions occurred in less than .03% of patients.

But even normal side effects — fatigue, arm pain and some flu-like symptoms — deterred some Utah patients from seeking a second shot.

“I am scheduled for my second dose on Wednesday. However, I have been debating on whether to go in and getting it or just skipping it overall. I’m afraid I might get another reaction to it,” said Marlene Ceballos, 30, of North Ogden. “My in-laws received their second does on Friday and all were sick throughout the weekend. They are better now but it scares me to think of not making it, so I might just skip it.”

Ceballos and her family all tested positive for COVID-19 in January, and she is hopeful that will confer some extra immunity to the virus. She said her biggest reasons to still make the second appointment would be to travel and to safely visit older relatives.

But others said they couldn’t afford to take the day or two off work to recover from the vaccine’s side effects.

“Within an hour of the first dose I had the worst sinus headache, sore throat, and stuffed nose. This lasted about three days,” said Shainalee Davis, a Logan 23-year-old who said she hasn’t been offered paid time off for vaccine recovery in her job as an automotive technician.

“I work a labor intensive job that I can’t exactly afford to show up to sick, not feeling well and risk the possibility of injuring myself or others,” she said.

Everyone else in her family has been fully vaccinated, Davis said.

One patient, a 58-year-old woman from Kaysville, has the autoimmune disorder Hashimoto’s disease and after the first dose experienced a “flare-up” of symptoms — headaches, pain and sudden weight gain. The woman, who asked not to be identified for medical privacy, said she’s still on the fence about the second dose.

“I am just worried that if the first shot threw my metabolism and adrenal system off so much, what would the second shot do? So I’m still weighing the pros and cons of the second shot,” she said. Like Ceballos, she said the freedom to travel was the main appeal of getting the second shot.

“I love to travel,” she said.

Not everyone who was overdue for shot No. 2 was worried about side effects. Some said they encountered website errors when they tried to schedule their second doses and ended up just waiting for sites to begin offering walk-in vaccines.

Hudachko noted that a pharmacy in Holladay several weeks ago found itself short of some doses for second-shot appointments, but those patients were shifted to Salt Lake County’s vaccine sites. He said he had “not heard of any similar situations since, and with the significant supply on-hand likely won’t.”

What happens if patients miss doses?

As with every shortfall in vaccine coverage, the biggest risk of patients missing doses is that COVID-19 will continue to spread and eventually produce variants that are more easily spread, more harmful or more vaccine-resistant than the strains presently infecting Utahns, Choudhary said.

“The push is to get both doses of the series ... as soon as possible,” Choudhary said. “It can temper the variants that are coming.”

So far, it appears that partially vaccinated people are less protected against all variants circulating in Utah and the rest of the nation, Choudhary said, but the difference in protection between full and partial vaccination has been relatively consistent from strain to strain. That may not always be the case as future variants develop, he noted.

If patients miss a dose, it is up to the individual provider to reach out to them, whether that is a local health department or a private pharmacy, Hudachko said.

For both the Pfizer and Moderna vaccines, patients who miss their second appointment still can “mount a full immune response” if they get the second shot within 42 days of the first shot, Hudachko said. There isn’t much data on how effective the vaccine is if people receive the second shot more than six weeks after the first, the CDC reports.

So far there is no recommendation to restart the entire vaccine course if a patient has not received their second dose after six weeks, Hudachko said; they just may not have as robust protection if the second shot falls after that timeframe.

As of Monday, 32.9% of Utahns were fully vaccinated, with 42.4% receiving at least one dose of vaccine, according to the Utah Department of Health.