Americans with underlying conditions are at greater risk of complications from COVID-19 infections. They may also be fast-tracked for receiving the vaccine to prevent the virus. But the U.S. Centers for Disease Control has issued a clarification on the possible side effects of the vaccine for those suffering from other conditions.

First, it indicates that anyone who has had a severe reaction to vaccines or is allergic to any ingredient in the COVID-19 vaccine should consult with their own physician to determine whether the vaccine is safe and beneficial. If the shot is administered, the recipient should be monitored for at least 30 minutes if they have previously had an allergic reaction to any vaccine.

The CDC is collecting reports of allergic reactions to the vaccine, whether reported by the physician or the public. A doctor in Boston, who has a history of severe shellfish allergies, had a severe reaction to the Moderna vaccine. He received the shot on Thursday and his reaction, he told an NBC news outlet, was immediate. When he realized it was not an anxious response, he used his EpiPen and had recovered fully by Friday.

Vaccine recipients may be offered the chance to enroll in V-safe, a smartphone tool using text messaging and surveys to check with those who have gotten the vaccine to help identify side effects after administration of the shot. It also sends second dose reminders. For more information on how to sign up, visit: www.cdc.gov/vsafe

Patients living with HIV can get the vaccine, but there is little information about the safety of the vaccine for those with compromised immune systems. HIV sufferers were included in clinical trials, but the data on specific safety for that subgroup is not available as of yet. There is also, the CDC writes, the possibility that the vaccine will be less effective for those with lowered immune responses.

The same may be true for those with autoimmune diseases. While there were members of that group included in the vaccine trials, there is no group-specific data as to the safety of the vaccine for them.

Patients who previously were diagnosed with Guillain-Barre syndrome — an uncommon disorder in which the immune system attacks the nerves outside the brain and spinal cord — may also take the vaccine and there have been no documented cases of the syndrome as a response to the vaccine.

Some cases of Bell’s palsy have been reported after vaccine administration, but not above what might occur in the general population and there has been no conclusion the cases were caused by the vaccination. Those who previously have had Bell’s palsy may be vaccinated.

The Food and Drug Administration reminds recipients that the Pfizer vaccine is part of the Countermeasures Injury Compensation Program, a federal system that may help pay for medical care and other expenses of some people who have been seriously injured by various medicines or vaccines, including the COVID-19 vaccine. Claims must be submitted within a year of receiving a vaccination.

Even after vaccination, residents should continue to wear a mask, practice social distancing, avoid crowded areas and wash hands frequently or use hand sanitizer with at least 60% alcohol.