MEDICAL ADVISORY: COVID-19 Vaccines and Interval Recommendations
Issued by: M. Mustafa Hirji, MD, MPH, FRCPC, Medical Officer of Health & Commissioner (Acting)
COVID-19 Vaccine Extended Interval for Second Dose
COVID-19 Vaccine Interval Recommendations
- NACI recommends that COVID-19 vaccines should not be given simultaneously with other vaccines (live or inactivated) to maximize benefits of COVID-19 vaccination
while minimizing any risks of harm (e.g., potential immune interference or the erroneous attribution of an adverse event following immunization (AEFI) to a particular vaccine)
- Except in a case where another vaccine is required for post-exposure prophylaxis
- In the event a COVID-19 vaccine is inadvertently administered at the same time as another vaccine, neither dose should be repeated
- Individuals who receive a non-COVID-19 vaccine are recommended to wait at least 14 days before getting a COVID-19 vaccine
- After receiving an mRNA or viral vector
COVID-19 vaccine, an interval of at least 28 days is recommended before receipt of a non-COVID-19 vaccine
- Refer to NACI Statement: Recommendations on the use of COVID-19 vaccines
Blood Products and Human Immunoglobulin Interval Recommendations
- COVID-19 vaccines should not be given simultaneously with monoclonal antibodies or convalescent plasma
- Administration of convalescent plasma or anti-SARS-CoV-2 monoclonal antibodies close to a COVID-19 vaccine may decrease effectiveness of a COVID-19 vaccine and/or anti-SARS-CoV-2 monoclonal antibodies
- There is insufficient evidence to guide timelines for receipt of both COVID-19 vaccine and any monoclonal antibodies or convalescent plasma for treatment or prevention of non-COVID-19 disease
- Timing of COVID-19 vaccine with the receipt of the above products should be determined by expert clinical opinion on a case-by-case basis
Tuberculin Skin Testing Intervals
- NACI updated their guidance regarding tuberculin skin tests (TST) and interferon gamma release assays (IGRA) to reflect COVID-19 vaccine administration
- Although the COVID-19 mRNA or viral vector vaccines are not live vaccines, possible implications on TSTs and IGRAs has not been fully evaluated
- Administering either mRNA or viral vector vaccines prior to TST or IGRA test may theoretically lead to a false-negative result due to their impact on cell-mediated immunity
TST and IGRA Testing Recommendations
If an
individual requires a TST or an IGRA test, the following is recommended:
- Administer and read the test prior to immunization or delay test at least four weeks after vaccination
- COVID-19 vaccination may take place at any time after all steps of the TST have been completed
In situations where an opportunity to perform a TST or IGRA test might be missed:
- Testing should not be delayed
- Re-testing
of individuals with negative results whom there is high suspicion of latent tuberculosis (TB) infection is recommended at least four weeks post COVID-19 vaccination to verify results
- Health care professionals are encouraged to weigh the risks and benefits of delaying TST or IGRA testing for each individual
- Refer to NACI’s Recommendations on the use of COVID-19 Vaccines
Reporting
- To report a tuberculin skin testing to Niagara Region Public Health, complete the online Tuberculosis Skin Test Report or fax the completed form to 905-682-6470
- For questions, please call the Infectious Disease program at 905-688-8248 or 1-888-505-6074 ext. 7543 Monday to Friday 8:30 a.m. to 4:30 p.m.
For further information on COVID-19 vaccines, refer to the Health Care
Professionals Frequently Asked Questions webpage or call the COVID-19 Health Care Professionals Information Line at 905-688-8248 and press 7, then press 1. The COVID-19 Health Care Professionals Information Line is available Monday to Friday 9:15 a.m. to 4:15 p.m.