In less than a year since the start of the COVID-19 pandemic, the scientific community has already managed to get multiple vaccine candidates to the final phase of testing before approval.
While a vaccine is needed to protect the world’s population, not all members of the population are being represented in clinical trials.
The virus has been especially deadly for older adults, and yet a new study has shown that they’re less likely to be included in the important trials that will determine if a vaccine is effective.
Currently, there are many COVID-19 vaccine and clinical trials underway throughout the world for adults.
The initial human studies, referred to as phase 1 trials, are immunogenicity and safety trials completed on a small number of closely monitored individuals.
After successful completion of this initial step, dose-ranging studies enroll hundreds of subjects into phase 2 trials to determine the safest and most effective dose that delivers the best immune protection.
The final phase typically enrolls thousands of individuals and provides the effectiveness and safety data required for final licensing.
Throughout all these stages of research, if the data raises concerns about effectiveness or safety, the Food and Drug Administration (FDA) may request additional information and studies. It can even completely halt clinical trials.
According to the study authors, people over the age of 65 make up 9 percent of the global population, but they account for 30 to 40 percent of all COVID-19 cases and 80 percent of all COVID-19 deaths.
For this study, researchers investigated the current COVID-19 studies by looking at 847 COVID-19 clinical trials and all 18 vaccine trials that were registered on ClinicalTrials.gov, the largest clinical trials database.
They discovered that in studies registered between October 2019 and June 2020, over 50 percent of COVID-19 clinical trials and vaccine trials excluded people over 65.
“When you begin in human studies, you want to test in a population [that] is healthy, without underlying conditions,” says Dr. Paul Goepfert, director of the Alabama Vaccine Research Clinic and professor of medicine and microbiology at the University of Alabama.
“Since many elderly [people] have underlying medical conditions, this excludes them from early studies, as [they] also do not respond to vaccines as well,” explained Goepfert.
When vaccines are designed and trialed, they’re intended to be given to both children and adults. Unlike medications, which are usually only given to a certain subset of the population, vaccines are given to a much broader audience. This includes vulnerable populations, such as elderly people, children, pregnant people, and people with chronic conditions.
There are various reasons why older adults are excluded from clinical trials. Some studies have an age-based cutoff, while others have indirect exclusion criteria, such as keeping out participants with an underlying condition. Others require participants to have a smartphone or other access to technology.
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Exclusions aren’t unusual and can be important to safeguard the health of the study volunteers. Some individuals have severe or unstable risk factors that are known and should be excluded.
But companies may push to study only the healthiest people, since it may make getting FDA approval more expedient.
Older individuals often experience more side effects from vaccines in comparison to younger, healthier individuals. These complications and side effects can sometimes slow the FDA approval process.
There can be additional hurdles in enrolling elderly individuals, as not all of them have smart devices, which may be crucial to participating in the trial. They may also have mobility issues that keep them from getting to physician appointments.
While all populations need to be included in the various studies, there’s a hesitancy in including more vulnerable populations like older adults, children, and pregnant people.
Some researchers have used common ailments as exclusion criteria to ensure that only the healthiest enroll in the initial phases of testing.
“There is a general fear of including pregnant persons in clinical trials that involve medications or vaccines out of fear of causing harm to a developing fetus,” said Dr. David Aronoff, director of the Division of Infectious Diseases at Vanderbilt School of Medicine in Nashville, Tennessee.
Aronoff said that excluding these people from trials could put them at risk, since there will be little to no data about how the vaccine will impact them before it’s released.
“More attention needs to be paid to including pregnant people in clinical trials before deciding to exclude them based solely out of fear,” Aronoff told Healthline.
Keeping people with common health conditions like diabetes out of the study population means only the healthiest individuals are studied. This group isn’t necessarily a true representation of the general population.
Traditionally, vaccines are tested in adults first before being expanded to children.
But children don’t appear to be especially at risk for severe COVID-19 symptoms. Many who have contracted the virus were either asymptomatic or had mild symptoms. Therefore, their symptoms are rarely life threatening or complex.
While many pharmaceutical companies haven’t yet studied how safe and effective vaccines are in children, that’s starting to change. This week, Pfizer announced that they’ve received permission from the FDA to include children as young as 12 in upcoming vaccine trials.
A public vaccine will be an important measure against COVID-19. But a successful vaccine must ensure the safety of the broader population. To create a vaccine that’s ready for the open market, many steps need to take place to ensure its safety for vulnerable groups.
Like any medication, creating a vaccine
There’s currently no true projection as to when a vaccine will be available to the public, but by keeping socially distant, wearing a mask, and ensuring utmost hygiene, the public can slow the spread of COVID-19.