When Taila Bold started to get a tickle in the back of her throat one afternoon in mid-July, COVID-19 did not even cross her mind.

As a volunteer in a hospice care facility, she was offered the vaccine early in the year and had two doses of the Moderna vaccine by the end of February.

In July, the country was in the midst of a two-month stretch when the Centers for Disease Control and Prevention said it was safe for fully vaccinated people to take their masks off, regardless of their surroundings, indoors and outdoors.

Bars and restaurants were opening again, and some employees who were fully vaccinated could go unmasked if they wanted to. Bold was among them. She works at a venue that hosts weddings and other events, and she’d been working there for about two weeks bartending.

The tickle that started on July 21 turned into a full-blown illness by the next afternoon. Her sore throat preceded full body aches, a severe headache, then a fever and chills. She thought it was some kind of bug, until she posted on Facebook.

Some friends suggest she get tested for COVID-19.

Bold got tested on July 24 at an urgent care clinic where doctors thought she probably just had a cold. They tested her just in case and sent her home with cough syrup.

So she was stunned when her result came back positive – even the caregivers at the urgent care clinic had assured her very few people tested positive if they were vaccinated.

That’s because breakthrough cases are incredibly rare. So far, just 5,879 breakthrough cases have been identified in Washington out of the 4.08 million fully vaccinated residents, or 0.1% of them.

Just three days after her positive result, the CDC began recommending everyone wear masks indoors again, regardless of vaccination status, especially in counties with high transmission.

But the delta variant’s rapid spread throughout the state has led to more breakthrough cases than when previous variants of the virus were circulating.

The delta variant made up 89% of the state’s sequenced samples at the end of July, indicating that it is the driving force behind the current surge in cases.

The vast majority of people who have breakthrough cases in Washington are not hospitalized. Just 7% of breakthrough cases so far have required hospitalization.

But for people like Bold, who got vaccinated and felt like she was safe, testing positive for what is considered a “mild” case didn’t feel so mild.

She had been wearing her mask at the grocery store and had not been at any large gatherings before she tested positive. She hadn’t worn her mask at work, however, which is where she thinks she might have gotten the virus, although she’ll never know for certain.

“They’d told us if we’d gotten our immunization, we didn’t have to wear masks, and they followed all safety protocols,” Bold said.

When symptoms linger

By Aug. 1, Bold technically could have returned to work, as current guidelines say she would no longer be contagious.

But by then, she still wasn’t feeling better. Her energy levels hadn’t rebounded, and she didn’t feel like she could be on her feet for a long shift. In the days following her positive test, Bold lost her sense of taste and smell.

“I rubbed raw garlic on my finger and couldn’t smell or taste it,” Bold said. “I couldn’t taste hot sauce; I could just feel it.”

Three weeks past her initial symptom onset, Bold is still not feeling 100%. The 53-year-old has no underlying health conditions or anything that she feels would put her at higher risk.

She checked in with her friends she’d seen leading up to the day she fell ill, and no one around her got sick.

Bold had to cancel a volunteer trip to Jamaica, and she might have to cancel more travel plans soon. She worries she might have long COVID.

Research still is being done on the long-term impacts for patients who continue to experience symptoms from COVID-19, but one researcher at the University of Washington who followed patients for nine months after testing positive found that a third of them had persistent symptoms.

If and how breakthrough infections can lead to long COVID is still being researched, but one study from Israel looked at breakthrough infections associated with the alpha variant, which predominantly resulted in mild infections, according to a study that followed health care workers there. A few health care workers studied continued to have symptoms after they were considered not contagious.

Bold’s breakthrough case is similar to the majority of those identified in Washington. So far, 88% of people who have a confirmed breakthrough case were symptomatic. People of all ages are testing positive for the virus after being fully vaccinated, and health officials have stressed that this is not out of the ordinary.

The CDC now recommends that anyone experiencing symptoms, regardless of vaccination status, get tested.

Vaccines ‘not the only strategy’

The COVID-19 vaccines are not 100% effective, but they are close.

A recent CDC analysis shows that among adults 75 and over, the vaccines are incredibly effective at reducing hospitalizations due to the virus.

In adults 75 and older, the Pfizer vaccine is 91% effective at preventing hospitalization; the Moderna vaccine is 96% effective; and the Johnson & Johnson vaccine is 85% effective.

When the vaccines were approved for emergency use at the end of 2020, clinical trials had shown them to be effective at preventing severe disease, hospitalization and death.

After a massive vaccination effort followed by the CDC loosening mask mandates in May, then Washington reopening in June, the public messaging signaled that the pandemic was nearly over.

But vaccines alone – without masking, distancing, testing or tracing – were never going to be the way forward.

“It’s not the only strategy; it never was,” said Dr. Josh Liao, a professor at the School of Public Health at the University of Washington.

Initially, the vaccine push was aimed at herd immunity, trying to beat back the virus before it could mutate and infect more people.

“I think that push was well-intentioned, but I think our slowness in getting there and the inability to get above where we are now has led to variants and the need to go backwards,” Liao said.

That push backwards includes other strategies used previously in the pandemic, like mask recommendations now in place virtually everywhere in the country.

“Masks have to happen now, but it wasn’t like once you got a shot you would never need to mask, distance or do those other things,” Liao said.

When the CDC changed its mask recommendation at the end of July, it did so after conducting an outbreak investigation in Provincetown, Massachusetts, where people gathered for multiple events earlier this summer, both indoors and outdoors at bars, restaurants and guest homes.

There were 469 cases confirmed in Massachusetts residents following the events, but 74% of the people who tested positive were fully vaccinated.

The delta variant was detected in the majority of these cases, and the CDC changed mask guidelines to reflect the fact that fully vaccinated people can transmit the virus in rare circumstances.

This was Bold’s biggest concern when she learned she tested positive.

“Honestly, my biggest fear is that I hope I didn’t inadvertently pass it on to other people,” Bold said.

To date, she isn’t aware of illness affecting anyone whom she was around during the days after her likely exposure, but with some fully vaccinated people never going to get tested, tracking these cases is difficult.

The CDC is now only tracking breakthrough cases that end in hospitalization or death, and while the state health department is tracking breakthrough cases in a more detailed way, asymptomatic breakthrough cases are likely still going undetected.

The delta variant is twice as transmissible as older strains of the virus, and some studies have found that it produces more viral loads in people, enabling easier transmission from one person to the next.

Bold will never know if she had the delta variant. Samples that are sequenced in Washington are not reported back to patients, due to federal regulations, according to the state Department of Health.

Breakthrough risk

The current reproductive rate of the virus in Washington is 2.14 as of late July, meaning that, on average, each infected person was giving the virus to more than two other people.

So how at risk is a vaccinated person to test positive?

Liao said answering that question with a specific number would be premature, but he is confident in saying it’s not zero.

The risk of contracting COVID-19 and getting severely ill is based on myriad factors, including but not limited to a person’s age, medical history and other health conditions; the degree of exposure based on the setting and the duration ; and the viral load of the infected person.

Higher-risk settings like restaurants and bars, as well as large gatherings, especially if they’re indoors, continue to present higher risks. Vaccination status, mask use, distancing and going outside can all play roles in how risky a setting is.

On Friday, the Department of Health sent out an advisory asking residents to keep gatherings small and outdoors whenever possible, and to avoid any large outdoor gatherings like concerts, fairs or festivals.

“I think with delta, what we’re seeing is that that rate of breakthrough is a bit higher because virus load is higher,” Dr. John Lynch, medical director of infection control at Harborview Medical Center in Seattle, said earlier this month.

The risk of breakthrough, experts say, should not be seen as a reason for not getting vaccinated, however.

Despite a higher rate of breakthrough, the vast majority of hospitalizations, cases and deaths in Washington this year have been in unvaccinated residents.

According to data compiled by the New York Times last week, in Washington you are 50 times more likely to be hospitalized with the virus if you are unvaccinated.

The delta variant is sweeping through groups of unvaccinated people and making them severely sick.

Statewide, and regionally, hospitals are filling with COVID patients again, and hospitalizations are nearing levels seen last December, when coronavirus hospitalizations were at their peak in Washington.

Bold, while frustrated with her continuing symptoms, is grateful she did not get sick enough to go to the hospital. Some patients hospitalized with the virus who weren’t vaccinated wish they were.

While people who are not vaccinated are much more at risk of severe disease, hospitalization and death due to COVID-19, there are still fully vaccinated people who will always be at higher risk.

The immunocompromised, people with certain cancer diagnoses, those on medications that weaken their immune systems or those who have received donated organs are still at risk of developing more severe disease with breakthrough cases, recent research has shown.

In fact, the Advisory Committee on Immunization Practices authorized a booster dose for these patients on Friday, in the hopes that a third dose might boost their immune response to the virus.

Just 66 people in Washington have died from the virus despite being fully vaccinated.

Of those who have died from a breakthrough case, the vast majority had underlying health conditions.

Nearly half of breakthrough cases are associated with an outbreak at a long-term care facility.

Vaccines are still the way forward, experts say, especially to ease the immense pressure currently on the health care system, but they aren’t the endgame anymore.

As Ed Yong reported in the Atlantic last week, “… the ‘zero COVID’ dream of fully stamping out the virus is a fantasy. Instead, the pandemic ends when almost everyone has immunity, preferably because they were vaccinated or alternatively because they were infected and survived.”

As Bold discovered, her vaccine might have saved her from a worse infection.

But when she returns to work, she plans to wear her mask. She also encourages anyone who has symptoms to get tested.

“Just because you’re immunized doesn’t mean you’re off scot-free,” Bold said, “and those that aren’t immunized, just pause, take a second and realize that any of us can be passing this along to anybody, and do your part.”

Editor’s note: A previous version of this story incorrectly calculated the percentage of breakthrough cases confirmed in Washington state thus far. So far, breakthrough cases represent .1% of fully vaccinated people in Washington state.