Immunocompromised Patients, COVID-19 Vaccine Responses

In a recent interview with Drug Topics®, Daniel S. Streetman, PharmD, MS, discussed the effects of the COVID-19 pandemic on patients with immunocompromised conditions and the importance of vaccinations. His background as a pharmacist and research experience in clinical pharmacology and pharmacogenomics extends to his interest in understanding why certain drugs do not affect patients the way they are expected to.

Immunocompromised patients can be defined in two categories, Streetman explained:

• Patients who have a particular medical condition or disease state that affects their immune system, such as patients with cancer and patients with HIV.
• Patients who are taking a drug that can impair the immune system, including those with certain cancers.

But this is not an all-inclusive list, according to Streetman. “I certainly have seen some of the other ways that some of the COVID issues have impacted these patients,” he said. “Pre-vaccine, you saw a lot of greater concern, fear, anxiety, amongst patients…where they're taking not only the recommendations about distancing or masking or avoidance and following those but to an even greater degree…out of an abundance of caution and desire to stay away from it.”

Additionally, Streetman explained the continuing concern patients have and the possible mistrust some may be feeling about getting vaccinated for COVID-19. He noted that patients are asking questions about ongoing precautions they may consider taking, including getting extra vaccine doses. Patients are also sometimes confused about contact and social distancing parameters moving forward. However, it’s not only immunocompromised patients who are struggling with these kinds of questions; their families, friends, and others in close contact are also asking questions about how to minimize their likelihood of contracting COVID-19 and passing the virus to individuals at increased risk for worse outcomes.

The immune system defends the body against infections, such as the COVID-19 infection. Without a normally functioning immune system it is easier for COVID-19 to take hold; and, once someone is exposed, it is more likely to lead to a clinically relevant, clinically important infection, according to Streetman. This is where vaccination can make a difference.

When looking at influenza or new pneumococcal vaccines that are widely recommended for immunocompromised patients, there is evidence that supports the findings with COVID-19 responses. Streeman explained that there are medications that have a large impact, such as a drug called rituximab, which knocks the B cells out of the bloodstream. However, he emphasized that although immunocompromised patients who take immunosuppressants may have a poorer response to vaccination, they should still get vaccinated.

The more intense the immunosuppressive therapy, the greater the likelihood that somebody is going to have a lower antibody response. This has key implications, according to Streetman: the greater number of immunosuppressants that somebody is on or the higher the dose of immunosuppressants that patients are using, the more likely there is to be a concern about antibody response.

However, this doesn't mean that patients taking these drugs wouldn't potentially benefit from getting vaccinated against COVID-19 - only that their antibody response may be lower. There are many other considerations when evaluating vaccination responses, cellular immunity being one example. “That type of response has not been looked at nearly as much as measuring antibody levels after vaccination,” said Streetman.

“The key takeaways are that, according to all the evidence that's out there, [COVID-19 vaccines] seem both safe and beneficial,” Streetman highlighted. “NET [Neuroendocrine tumor cancer] patients still stand to benefit from it, even if the antibody responses diminished somewhat.”

“If I could give a second piece of advice, and more specific to health care providers, it would be to understand or be aware that a number of immunosuppressive medications may need to be altered as far as their timing around the time that someone gets a COVID vaccine. And so, it's important that pharmacists either learn those things and become aware of them, or more realistically that they find a trusted resource that they can consult,” he concluded.