World health authorities attempt to explain the increasing number of breakthrough infections
Breakthrough infections — which refer to cases of fully vaccinated people who are hit by Covid-19 — were once considered extremely rare, but statistics over the past two weeks showed they have become more frequent on Guam since the emergence of the delta variant.
The growing number of breakthrough cases, coupled with Guam's first Covid-related death involving a vaccinated patient, has raised questions as to the efficacy of the vaccines.
World health authorities, however, provide ambiguous explanations.
In last week’s report, the Centers for Disease Control and Prevention said the Covid-19 vaccines approved in the United States are highly effective at preventing severe and prolonged disease and death, and providing protection against the delta variant.
“But they are not 100 percent effective, and some fully vaccinated people will become and experience illness,” CDC said.
At the Guam Memorial Hospital, two vaccinated patients were in the ICU receiving supplemental oxygen on Friday.
“Others are in telemetry and in the regular Covid Medical Unit – some not needing supplemental 02 but receiving other types of medical treatment for underlying medical conditions,” GMH administrator Lilian Perez-Posadas said.
She said one unvaccinated patient was also in ICU on ventilator support. Others were receiving supplemental oxygen through either high-flow nasal cannula or regular nerve action potential nasal cannula.
“We continue to currently experience a shortage of ‘staffed’ beds primarily due to a shortage of nurses,” Posadas said.
Even though the GMH staff employees are fully vaccinated, Posadas confirmed that some employees have tested positive for Covid-19.
"We’re managing as best we can. The staff is committed and high-spirited to stay the course and provide the care that’s needed," Posadas said.
Non-Covid patients are being treated at the Skilled Nursing Unit in Barrigada Heights, Posadas said.
As of last night, GMH had 40 Covid-19 patients; 23 are unvaccinated, 16 are vaccinated and one was not eligible to receive a vaccine. In total, Guam has 72 Covid-related hospital admissions, including the 32 patients at Guam Regional Medical Center.
The Department of Public Health and Social Services reported a preliminary case count of 85 new positive cases from 651 specimens analyzed on Sept. 11.
Additional results are pending analysis and submission from other clinics and will be reported sometime today.
To date, there have been a total of 12,379 officially reported cases of Covid-19 with 159 deaths, 2,776 cases in active isolation, and 9,445 not in active isolation.
As of Sept. 10, Guam's Covid Area Risk score is 39.2.
CDC maintained that vaccines play a crucial role in limiting the spread of the virus and minimizing severe disease.
"Although vaccines are highly effective, they are not perfect, and there will be vaccine breakthrough infections,” CDC said.
CDC said even though the risk of breakthrough infections is low, “there will be thousands of fully vaccinated people who become infected and able to infect others, especially with the surging spread of the delta variant.”
Providing insights into breakthrough infections, CDC explained how the vaccine works.
"Covid-19 vaccines teach our immune system how to recognize and fight the virus that causes Covid-19," CDC said.
The health agency noted that it typically takes two weeks after vaccination for the body to build immunity or protection against the virus that causes Covid-19.
“That means it is possible a person could still get Covid-19 before or just after vaccination and then get sick because the vaccine did not have enough time to build protection,” CDC said.
CDC said fully vaccinated people with delta variant breakthrough infections can spread the virus to others. However, vaccinated people appear to spread the virus for a shorter time.
There are still medical gaps that need to be plugged.
“We are still learning how many people have to be vaccinated against Covid-19 before the population can be considered protected,” CDC said.
Just the same, CDC found more value in vaccines.
“Even after delta became the most dominant variant, fully vaccinated people were five times less likely to be infected with Covid, 10 times less likely to be hospitalized because of it and 10 times less likely to die of virus-associated complications compared with unvaccinated people,” CDC said.
Another study published last week in The Lancet Infectious Diseases journal explained that the odds of post-vaccination infection following the first dose were increased in frail older adults.
"Compared with unvaccinated controls after their second vaccine dose, individuals were less likely to have prolonged illness (symptoms for 28 days), more than five symptoms in the first week of illness or present to the hospital. Most symptoms were less common in vaccinated versus unvaccinated participants,” the report said.
The Lancet study found that fully vaccinated individuals with Covid-19, especially if they were 60 years or older, were likely to be completely asymptomatic than were unvaccinated.
“This finding might support caution around relaxing physical distancing and other personal protective measures in the post-vaccination era, particularly around frail older adults and individuals living in more deprived areas, even if these individuals are vaccinated,” the Lancet report states. “Our findings might also have implications for strategies such as booster vaccinations.”