FAQs COVID-19 Vaccine

The following questions and answers have been developed by the National Immunisation Office.

 

Should unvaccinated people who have had COVID‐19 infection be offered COVID‐19 vaccine?

Yes. People who have had COVID‐19 infection should be offered COVID‐19 vaccines.

The primary vaccination course should be deferred until clinical recovery from COVID‐19 and at least four weeks after diagnosis or onset of symptoms, or four weeks from the first PCR positive specimen in those who are asymptomatic. Those with persisting symptoms post COVID-19 may be vaccinated unless there is evidence of recent clinical deterioration.

What if somebody is diagnosed with COVID‐19 infection after a first dose of vaccine of the primary vaccination course?

Vaccination with the second dose should be deferred until clinical recovery from COVID‐19 and at least four weeks after diagnosis or onset of symptoms, or four weeks from the first PCR positive specimen in those who are asymptomatic.

What if the second dose of COVID‐19 vaccine in the primary vaccination course is administered at less than the recommended interval?

The day that the first dose of vaccine is given is day 0

Comirnaty® (Pfizer BioNTech)

The course consists of 2 doses administered 21-28 days apart.

  • If the second dose is given at an interval of less than 17 days, this this is not considered a valid dose. A third dose should be given at least 28 days after the second (invalid) vaccine.
  • If a dose is given between 17 and 27 days after the first dose, this is considered a valid dose.

 

Nuvaxovid® (Novavax)

The course consists of 2 doses administered three weeks (21 days) apart.

  • If a second dose is given at an interval of less than 17 days, it is not considered a valid dose. However there is no evidence of the efficacy of safety of an additional dose in these circumstances so revaccination is not advised.
  • If a second dose is given at an interval of between 17 and 20 days after the first dose, this is considered a valid dose.

For the primary vaccination course, what if the second dose of a COVID‐19 vaccine is administered at longer than the recommended interval?

If the interval between doses is longer than the recommended interval, the second dose should still be given. The course does not need to be restarted.

What if the vaccine leaks during administration?

If some of the vaccine leaks out of the syringe during administration this is not a valid dose. A further dose of the vaccine should be administered at a separate site at the same visit.

What if a vaccine is given after the expiry date or after the use before or discard time?

If a vaccine is given after the expiry date or after the use before or discard date and time it is considered an invalid dose, and the dose should be repeated that day or as soon as possible.

This should be explained to the person and a correctly diluted dose of the vaccine should be given as soon as possible. This should be reported to HPRA and an incident report form completed.

What if the whole multi‐dose vial of vaccine is administered instead of the recommended dose?

Trial data showed that higher doses of vaccine were not harmful but the person is more likely to have more local reactions with very painful arms being reported.

Trial data of Nuvaxovid® showed that higher doses of the vaccine were not harmful but the person is more likely to have more local and systemic reactions (malaise, fatigue, myalgia, headache arthralgia and fever) when a higher second dose was given. 

The person should be reassured that this is not harmful but that they are more likely to experience the adverse events as above. 

They should be given their second dose of vaccine according to the recommended schedule. This should be reported to HPRA and an incident report form completed. 

What if only the diluent of Comirnaty® (Pfizer BioNTech) is given?

The diluent for Comirnaty® (Pfizer BioNTech) is sodium chloride, which is salt and purified water so no adverse reactions would be expected.

This should be explained to the person and a correctly diluted dose of the vaccine should be given as soon as possible. This should be reported to HPRA and an incident report form completed.

What if an over‐diluted Comirnaty® (Pfizer BioNTech) vaccine is administered?

In this case, the person will not have received a sufficient dose of vaccine for protection.

This should be explained to the person and a correctly diluted dose of the vaccine should be given as soon as possible. This should be reported to HPRA and an incident report form completed.

In settings where doses may be prepared in advance, if eight doses have been obtained from a vial, each of the syringes must be examined by another person to identify the syringe with less than 0.3ml. If all syringes contain 0.3ml then more than 1.8ml must have been added and the vial has been over-diluted.

What if a person under 12 years is given Comirnaty® 30 micrograms/dose (Pfizer BioNTech) vaccine inadvertently?

The vaccine formulation used for adults is licensed by the EMA from age 12 years and above only.

The young person and their parent/guardians should be informed. A HSE incident form should be

completed and the incident reported to the HPRA. The young person and their parents/guardians should be advised regarding the common adverse events expected after vaccination. They should also be informed of the very rare adverse event of myocarditis and pericarditis, the symptoms to be aware of, and to seek medical attention if they develop.

What if a person under 30 years is given Spikevax® inadvertently?

If a person under the age of 30 years receives the vaccine inadvertently, an incident form should be completed. The person (and their parents/guardians if less than 16 years old) should be advised regarding the common adverse events expected after vaccination. They should also be advised of the very rare reported adverse event of myocarditis and pericarditis and the symptoms to be aware of. If the person who received the vaccine is less than 12 years of age, the incident should also be reported to the HPRA. (the vaccine is not licensed for this age-group).

What if a person under 18 years is given Jcovden ® (Janssen) inadvertently?

This should be reported to the HPRA and an incident form completed. The person (and their parents/guardians if less than 16 years old) should be advised regarding the common adverse events expected after vaccination.

They should be advised of Thrombosis with Thrombocytopenia syndrome (TTS) reported very rarely after vaccination, and of the symptoms to be aware of, and to seek urgent medical attention should these appear. They should also be advised of the very rare reported adverse event of capillary leak syndrome and of the symptoms to be aware of. They should also be advised of the very rare adverse event of Guillain-Barré syndrome and of the symptoms to be aware of.

What if a person aged under 12 is given Nuvaxovid® inadvertently?

This should be reported to the HPRA and an incident form completed. The person (and their parents/guardians if less than 16 years old) should be advised regarding the common adverse events expected after vaccination.

The parents/guardians should also be informed of the increased risk of myocarditis and pericarditis following vaccination with Nuvaxovid. The parents/guardians should be advised to promptly seek medical attention if the child develops acute and persisting chest pain, palpitations or shortness of breath in the days after vaccination.

The frequency of myocarditis and pericarditis after Nuvaxovid® cannot currently be estimated from the available data.

Does a woman who wishes to conceive need to leave any interval after getting COVID‐19 vaccines before getting pregnant?

It is not necessary to leave any interval after having the vaccine and becoming pregnant.

Can COVID‐19 vaccines affect fertility?

There is no biologically plausible reason why the vaccines would affect fertility. The vaccines cannot interact with a person’s DNA. The EMA licensed documentation states that animal studies do not indicate direct or indirect harmful effects on fertility.

Where can COVID‐19 vaccine be given in the event that a person cannot receive the vaccine in the deltoid muscle?

In the event that a person cannot receive the vaccine in the deltoid muscle, the vaccine can be given into the vastus lateralis muscle.

What size needle should be used to vaccinate people with an elevated BMI?

If it is available, it is recommended to use a 23‐25 gauge 40mm needle when vaccinating females >90kg and males >120kg. If a 38‐40 mm needle is not available, a 23‐25 gauge 25mm needle should be used.

(As an example, the quadrivalent inactivated influenza flu vaccine that is licensed and used in Ireland and in Europe comes in a prefilled syringe with a fixed needle attached, and the needle is not the longer 40mm in length).

Can other vaccines be co-administered with COVID-19 vaccines for those aged 12 years and older?

Yes, other vaccines may be co-administered with COVID-19 vaccine or at any interval. If other vaccines are being given at the same time as COVID-19 vaccines it is preferable to give them indifferent limbs.

The exception to this is mpox (formally known as monkeypox/smallpox) vaccine. There should be an interval of four weeks between mpox vaccine and a subsequent COVID-19 vaccine because of the unknown risk of myocarditis. No interval is required between a COVID-19 vaccine and a subsequent mpox vaccine (see Chapter 13a of Immunisation Guidelines).

What is the recommended minimum interval between 1st and 2nd dose of a heterologous primary course (2 different vaccines)?

The recommended minimum interval between a 1st and 2nd dose in a heterologous primary course is 28 days. 

What is the advice if someone has received a COVID-19 vaccine outside Ireland?

Those who have documentary evidence of a complete COVID-19 vaccination course with a COVID-19 vaccine authorised by the FDA, MHRA or recommended by WHO should be considered fully vaccinated.

Those who have partially completed a COVID-19 vaccine course with a vaccine authorised by the FDA, MHRA or recommended by WHO should be offered an EMA authorised COVID-19 vaccine to complete the series, and then should be considered fully vaccinated. The minimum interval between the last vaccine dose and an EMA authorised COVID-19 vaccine is 28 days.

Those who have received a partial or complete course of COVID-19 vaccine not authorised by the FDA, MHRA or recommended by WHO should be offered a complete course of an EMA authorised COVID-19 vaccine. The minimum interval between the last dose and an EMA authorised COVID-19 vaccine is 28 days.

What is the advice for timing of the first mRNA booster dose in someone who has had a breakthrough infection since completing their primary vaccination course?

If a person has had laboratory confirmed (PCR) breakthrough COVID-19 infection/antigen positive infection with symptoms since completion of their primary course, the mRNA booster dose should be deferred for at least 4 months.  In exceptional circumstances a 3 month interval may be used.

What is the advice for timing of an additional dose of vaccine for an immunocompromised person who has had a breakthrough infection since completing their primary vaccination course?

If a person has had laboratory confirmed (PCR) breakthrough COVID-19 infection since completion of their primary course, the additional dose should be deferred for at least 4 months after diagnosis. If it is not possible to establish if a person had breakthrough COVID-19 infection in this timeframe, they may be vaccinated.

What if a person becomes immunocompromised after receiving their booster dose. Do they then need an additional dose as well?

No. Individuals with immune-compromise at the time of primary COVID-19 vaccination may have a sub-optimal response to the vaccine. They are recommended an additional dose to enhance their response to the primary vaccination course. It is a person’s condition at the time that they receive the primary vaccination course that determines whether or not they need an additional dose.

The immunocompromising conditions associated with a suboptimal response to the primary vaccination course are shaded in blue in Table 5a.2 of the Immunisation Guidelines

What if a person is immunocompromised at the time that they receive the booster dose. Do they then need an additional dose as well?

No. Individuals with immune-compromise at the time of primary COVID-19 vaccination may have a sub-optimal response to the vaccine. They are recommended an additional dose to enhance their response to the primary vaccination course. It is person’s condition at the time that they receive the primary vaccination course that determines whether or not they need an additional dose.

However their response to the booster dose may be sub-optimal, so they are recommended to receive a 2nd booster dose, which should be given 4 months after the 1st booster dose.

The immunocompromising conditions associated with a suboptimal response to the primary vaccination course are shaded in blue in Table 5a.2 of the Immunisation Guidelines

What if an additional dose of an mRNA vaccine for immunocompromised people is given before the minimum interval? Is there a need to repeat the dose?

If the vaccine is given before the minimuminterval (3 months), there is no evidence as to the safety and efficacy of giving a further dose under these circumstances to complete the primary course. The dose should not be repeated. However, a booster vaccine should still be given at the recommended interval (at least 4 months).

The person (and their parents/guardians if less than 16 years old) should be advised regarding the error and the incident reported. The error should be reported to the HPRA.

What if an mRNA booster dose is given before the minimum interval? Is there a need to repeat the dose?

If the vaccine is given before the minimum interval there is no evidence as to the safety and efficacy of giving a further dose under these circumstances. The dose should not be repeated.

The person (and their parents or guardian if less than 16 years old) should be advised regarding the error and the incident reported. The error should be reported to the HPRA.

What if a person less than 30 years of age is given a booster or an additional dose of Spikevax®?

The person should be informed of the error. An incident form completed. The person should be informed of the risks of very rare side effects from the vaccine including myocarditis and pericarditis and the symptoms to be aware of.

Can Spikevax® BA.4-/5 be used foras a primary course of vaccination?

No, Spikevax® BA.4-5  should only be used as a booster vaccine in people aged 30 years and older.  

Can Nuvaxovid® be used as an additional dose for people who have a contraindication to an mRNA vaccine or who have declined other COVID-19 vaccines?

Yes. Nuvaxovid® can be considered in these circumstances in people aged 12 years and older. Nuvaxovid is a protein sub unit vaccine. 

What is the recommended interval for the additional dose of Nuvaxovid?

The recommended interval is 4 months after the completion of the primary vaccination course. 

What is the recommended interval for the booster dose of Nuvaxovid?

In circumstances where an individual has received two doses of Nuvaxovid for their primary vaccination course, they may be offered Nuvaxovid for their first booster dose. This booster dose should be given at least 4 months after their last Nuvaxovid dose (in exceptional circumstances an interval of 3 months may be used).

If a person has been vaccinated with another type of COVID-19 vaccine for their primary course and first booster dose, and there is a contraindication or precaution to an mRNA vaccine or they have declined other COVID-19 vaccines, a booster dose of Nuvaxovid may be considered. This booster dose should be given at least 4 months after their last dose of a COVID-19 vaccine (in exceptional circumstances an interval of 3 months may be used).

For healthy people aged 18-49 years who are receiving Nuvaxovid as their second COVID-19 booster vaccine (and who have not received a homologous Nuvaxovid primary vaccination) the booster dose should be given at least 6 months after their last dose of another type of COVID-19 vaccine or COVID-19 infection. 

Can Nuvaxovid be used in pregnancy if there is a contraindication to an mRNA vaccine or if a person has declined other COVID-19 vaccines?

Nuvaxovid® can be considered in these circumstances. However, there is limited experience with use of the vaccine in pregnant women.

Administration may be considered when the benefits outweigh the potential risks to the mother or the fetus and when mRNA vaccines are contraindicated or declined.

Can other vaccines be co-administered along with Nuvaxovid®?

Like other COVID-19 vaccines, Nuvaxovid® may be administered at the same time as other vaccines or at any interval. Co-administered vaccines should be given in different arms. The only exception to this is mpox (formerly known as monkeypox)/smallpox vaccine. There should be an interval of four weeks between mpox/smallpox vaccine and a subsequent COVID-19 vaccine because of the unknown risk of myocarditis. No interval is required between a COVID-19 vaccine and a subsequent mpox/smallpox vaccine (see Chapter 13a of the National Immunisation Advisory Committee (NIAC) Immunisation Guidelines for Ireland).

Can adapted mRNA vaccines be used for a primary course?

Only Comirnaty Original/Omicron BA.4-5 30 micrograms (0.3ml) for those aged 12 years and older and Comirnaty Original/Omicron BA.4-5 10 micrograms (0.2ml) for those aged 5-11 years may be used for a primary vaccination course.

All other adapted mRNA vaccines are only recommended for use as booster doses.

What if a person is given an adapted vaccine as a primary course?

Comirnaty Original/Omicron BA.4-5 30 micrograms (0.3ml) for those aged 12 years and older and Comirnaty Original/Omicron BA.4-5 10 micrograms (0.2ml) for those aged 5-11 years may be used for the primary vaccination course in the appropriate age groups for which these vaccines are licensed.

If any of the other adapted COVID-19 vaccines are inadvertently given as a primary course, then the person (or the parent/guardian if aged <16) should be informed of the error, an incident form completed and the error should be reported to the HPRA.

  • If Comirnaty Original/ Omicron BA.1 is inadvertently given as a first dose in a primary series, it can be regarded as a valid dose. The primary series should be completed with Comirnaty or Comirnaty Original/ Omicron BA.4-5.
  • If Spikevax bivalent Original/Omicron BA.1 or Spikevax bivalent Original/Omicron BA.4-5 is inadvertently given as a primary series dose, the dose should be repeated immediately with the 100 microgram Spikevax Original vaccine or Comirnaty Original because the Spikevax bivalent Original/Omicron BA.1 vaccine dose (50 micrograms) or Spikevax bivalent Original/Omicron BA.4-5 vaccine dose (50 micrograms) is lower than the dose authorised for the primary series.

Delaying the repeat dose for eight weeks after the invalid dose may be considered based on the rare risk of myocarditis and pericarditis from mRNA vaccines. Individual risk for COVID-19 and the likelihood for an adverse event following vaccination should be taken into consideration when recommending a longer interval.

What is a person is given a booster dose of an mRNA vaccine original formulation (Comirnaty® 30mcg/dose, Comirnaty® Ready to Use, or Spikevax®)?

These vaccines are recommended by the National Immunisation Advisory Committee and have demonstrated effectiveness against severe COVID-19 disease (although adapted booster vaccines are preferred). The person should be informed of the vaccine they have received but reassured that they have received an approved vaccine.

Local processes should be checked to ensure that the correct or preferred vaccine is administered.

 

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This page was updated on 23 March 2023