Clinical Considerations for Special Situations and Populations

COVID-19 vaccination and prior SARS-CoV-2 infection

COVID-19 vaccination recommendations apply regardless of prior symptomatic or asymptomatic SARS-CoV-2 infection, including people with Long COVID.

People who recently had SARS-CoV-2 infection may consider delaying a COVID-19 vaccine dose by up to 3 months from symptom onset or positive test (if infection was asymptomatic). A low risk of reinfection has generally been observed in the months following infection. Individual factors such as risk of severe COVID-19 and current indicators of community transmission should be taken into account when determining whether to delay getting a COVID-19 vaccination after infection.

COVID-19 vaccination and MIS-C and MIS-A

Multisystem inflammatory syndrome in children (MIS-C) and multisystem inflammatory syndrome in adults (MIS-A) are rare and potentially serious post-infectious complications of SARS-CoV-2 infection. Both are associated with a hyperinflammatory immune response to SARS-CoV-2 infection. MIS-C incidence in the United States has declined by over 98% since the peak of the COVID-19 pandemic despite continued SARS-CoV-2 transmission.

There have been rare reports of multisystem inflammatory syndrome (MIS)-like illness after COVID-19 vaccination identified from U.S. surveillance (<1 MIS-C case per million vaccinated children without laboratory evidence of SARS-CoV-2 infection). However, whether there is a causal relationship between COVID-19 vaccination and MIS-like illness is unknown.

Considerations for initiating COVID-19 vaccination in people with a history of MIS-C or MIS-A

A study (published in 2023) found that children with a history of MIS-C were not at increased risk for the reoccurrence of MIS-C or other serious adverse events including myocarditis. Clinical experts consider the benefits of COVID-19 vaccination for people with a history of MIS-C or MIS-A to outweigh a theoretical risk of a MIS-like illness or the rare risk of myocarditis following COVID-19 vaccination for those who meet the following two recovery criteria:

1. Clinical recovery has been achieved, including return to baseline cardiac function; and
2. It has been at least 90 days after the diagnosis of MIS-C or MIS-A

COVID-19 vaccination may also be considered for people who had MIS-C or MIS-A and do not meet both criteria, at the discretion of their clinical care team. Clinical experts view clinical recovery, including return to baseline cardiac function, as an important factor when considering COVID-19 vaccination. Additional factors, such as the risk of severe COVID-19 due to age or certain medical conditions, may also be considered.

Considerations for administration of subsequent COVID-19 vaccine doses in people diagnosed with MIS-C or MIS-A after COVID-19 vaccination

Onset of MIS more than 60 days after most recent COVID-19 vaccine dose

Administration of subsequent COVID-19 vaccine doses may be considered for those who meet the two recovery criteria described in the section immediately above.

Onset of MIS 60 days or fewer after most recent COVID-19 vaccine dose

For persons in this category who meet the recovery criteria described in the section immediately above, the decision whether to administer subsequent COVID-19 vaccine doses should be made on an individual basis by the clinical care team and patient or parent or guardian. Subsequent COVID-19 vaccine doses should especially be considered if there is strong evidence that the MIS-C or MIS-A was a complication of a recent SARS-CoV-2 infection.

Pregnant and breastfeeding women

FDA package inserts state that the risks of these vaccines to pregnant and breastfeeding women, babies in utero, and breastfed children remains unknown. Clinicians are strongly encouraged to review the known and unknown risks of COVID-19 vaccines with pregnant and breastfeeding women and discuss the risks and benefits of specific products with them before making vaccination decisions. The following information is provided in the FDA package inserts:

Comirnaty: https://www.fda.gov/vaccines-blood-biologics/comirnaty

• Section 8.1 "There are no available data with COMIRNATY use in pregnant women before 24 weeks gestation to inform about risks for major birth defects and miscarriage. [...] The available trial data are insufficient to establish or exclude vaccine-associated risk of congenital anomalies because COMIRNATY was not administered in the first trimester (the period when the risk of major congenital anomalies is highest)."
• Section 8.2 "It is not known whether COMIRNATY is excreted in human milk. Data are not available to assess the effects of COMIRNATY on the breastfed infant or on milk production/excretion."

Mnexspike: https://www.fda.gov/vaccines-blood-biologics/mnexspike

• Section 8.1 "Available data on MNEXSPIKE administered to pregnant women are insufficient to inform vaccine-associated risks in pregnancy."
• Section 8.2 "It is not known whether MNEXSPIKE is excreted in human milk. Data are not available to assess the effects of MNEXSPIKE on the breastfed infant or on milk production/excretion."

Nuvaxovid: https://www.fda.gov/vaccines-blood-biologics/vaccines/nuvaxovid

• Section 8.1 "Available data on 777 NUVAXOVID administered to pregnant women are insufficient to inform vaccine-associated 778 risks in pregnancy."
• Section 8.2 "It is not known whether NUVAXOVID is excreted in human milk. Data are not available to 802 assess the effects of NUVAXOVID on the breastfed infant or on milk production/excretion."

Spikevax: https://www.fda.gov/vaccines-blood-biologics/spikevax

• Section 8.1 "Available data on SPIKEVAX administered to pregnant women are insufficient to inform vaccine-associated risks in pregnancy."
• Section 8.2 “It is not known whether SPIKEVAX is excreted in human milk. Data are not available to assess the effects of SPIKEVAX on the breastfed infant or on milk production/excretion”