g logo nhs blue


This guidance was originally published provisionally, ahead of authorisation of any COVID-19 vaccine in the UK, to provide information to those who will be involved in the COVID-19 national vaccination programme.

In the UK, three COVID-19 vaccines are currently in use in the UK national COVID-19 vaccination programme:

  • COVID-19 Vaccine Pfizer BioNTech (Comirnaty) was given authorisation for temporary supply by the Medicines and Healthcare products Regulatory Agency (MHRA) on 2 December 2020 and then granted conditional marketing authorisation (CMA) on 9 July 2021
  • COVID-19 Vaccine AstraZeneca (Vaxzevria) was given authorisation for temporary supply by the MHRA on 30 December 2020 and then granted CMA on 24 June 2021
  • COVID-19 Vaccine Moderna (Spikevax) was given authorisation for temporary supply by the MHRA on 8 January 2021 and then granted CMA on 1 April 2021.

Information about any other COVID-19 vaccines that are given regulatory approval will be added when this occurs.

The information in this guidance was correct at time of publication. As COVID-19 is an evolving disease, some of the information may change. Updates will be made to this document as new information becomes available. You are therefore advised to consult the online version of the full guidance to ensure you are accessing the latest information.

This Guidelines summary excludes some information from the full guideline. For the complete set of recommendations, refer to the full guideline. 

This summary has been abridged for print. View the full summary at guidelines.co.uk/455707.article

COVID-19 vaccination programme

  • The aim of the COVID-19 vaccination programme is to protect those who are at highest risk from serious illness or death from COVID-19 or at risk of transmitting infection to multiple vulnerable persons or other staff in a health or social care environment
  • For information about COVID vaccines in development, see the LSHTM COVID-19 vaccine tracker.

Groups affected by COVID-19

  • Increasing age and male gender have been shown to be significant risk factors for severe disease, and infection fatality ratios are highest in the oldest age groups
  • Comorbidities such as diabetes and severe asthma are associated with an increased risk of death, and obesity and other underlying health conditions can increase the risk for some people 
  • Deprivation and being from a black, Asian, or minority ethnic group also results in an increased risk of death from COVID-19
  • Health and social care workers are at increased risk of acquiring infection in their work setting and they may potentially transmit the virus to their families and to those in their care
  • Further information on high risk groups (those who are clinically extremely vulnerable) and moderate risk groups (those who are clinically vulnerable) can be found on the NHS.UK webpage: Who’s at higher risk from coronavirus (COVID-19)

COVID-19 vaccination eligibility

Vaccine priority groups

COVID-19 vaccines

  • In the UK, three COVID-19 vaccines are currently in use in the UK national COVID-19 vaccination programme. These are:
    • COVID-19 Vaccine Pfizer BioNTech (Comirnaty) given authorisation for temporary supply by the MHRA on 2 December 2020 and then granted CMA on 9 July 2021
    • COVID-19 Vaccine AstraZeneca (Vaxzevria) given authorisation for temporary supply by the MHRA on 30 December 2020 and then granted CMA on 24 June 2021
    • COVID-19 Vaccine Moderna (Spikevax) given authorisation for temporary supply by the MHRA on 8 January 2021 and then granted CMA on 1 April 2021
  • Any other COVID-19 vaccines that are given regulatory approval and supplied in the UK will be added to this summary when this occurs
  • The Pfizer BioNTech (Comirnaty) and Moderna (Spikevax) COVID-19 vaccines use an mRNA platform and the COVID-19 Vaccine AstraZeneca (Vaxzevria) is an adenovirus vector vaccine
  • All the currently authorised vaccines are supplied in multi-dose vials and require completion of a two-dose primary course. Using multi-dose vials can improve the efficiency of vaccine manufacture and distribution, enabling vaccine availability at the earliest opportunity.

Previous incomplete vaccination

  • If the vaccine course is interrupted or delayed, it should be resumed using the same vaccine but the first dose should not be repeated
  • Evidence from trials suggest that those who receive mixed schedules—including mRNA and adenovirus vectored vaccines—make a good immune response, although rates of side effects following the second dose are higher compared to those who received the same vaccine for both doses. Accumulating evidence now supports the use of heterologous schedules for primary immunisation and these are now recognised by the European Medical Agency
  • For individuals who started the schedule and who attend for vaccination where the same vaccine is not suitable, is unknown or not available (for example, if the individual received their first dose abroad), one dose of the locally available product should be given to complete the schedule if that vaccine is suitable for age and not contraindicated (see Appendix 1 in the full guideline and the Individuals who received COVID-19 vaccination overseas section below). Individuals who experienced severe expected reactions after a first dose of AstraZeneca or Pfizer BioNTech vaccines should be informed about the higher rate of such reactions when they receive a second dose of an alternate vaccine.

Individuals who received COVID-19 vaccination overseas

  • If a person (aged 18 years and over) has received a first dose of COVID-19 vaccine overseas that is also available in the UK, they should receive the same vaccine for their second dose (unless contraindicated)
  • If the vaccine they received for their first dose is not available in the UK, the most similar alternative should be offered
  • If the vaccine received overseas is not listed in the table (see Appendix 1 in the full guidance), a full course of the appropriate vaccine recommended for the individual in the UK (which may depend on their age) should be given
  • Those who are eligible to receive a booster dose (see Green Book COVID-19 chapter) should be given a full dose (0.3 ml) of Pfizer BioNTech COVID-19 vaccine or a half dose (0.25 ml) of Moderna vaccine. In this instance, the minimum interval of 3 months should be from their final primary dose. So for those considered fully vaccinated before arrival, the 3 months is taken from their final dose given overseas; for those requiring one or more UK doses, the 3-month interval is taken from the final ‘additional’ dose given in the UK
  • The above advice applies to individuals aged 18 years and older. Individuals aged under 18 will need individual assessment as to whether additional doses are recommended
  • The various groups of vaccines are:
    • adenovirus (ChAdOx) vector: AstraZeneca (Vaxzevria), Covishield
    • mRNA: Pfizer BioNTech (Comirnaty), Moderna (Spikevax)
    • whole inactivated coronavirus: Sinopharm, Sinovac, Covaxin
  • The other adenovirus-based vaccines (Janssen, Sputnik, CanSinoBio) use different vectors and so are not immunologically the same as either the AstraZeneca or Covishield adenovirus vector vaccines. However, as they, and the Novavax vaccine, are all based on spike protein, the vaccine course can be completed with any of the locally available vaccines as appropriate for the individual’s age.

COVID-19 vaccines schedule

  • For both adenovirus vector and mRNA vaccines, there is evidence of better immune response and/or protection where longer intervals between doses in the primary schedule are used
  • The JCVI is currently recommending an interval of 8 weeks between doses of all the available COVID-19 vaccines where a two-dose primary schedule is used for adults and children at high risk. Operationally, using the same minimum interval for all of the COVID-19 vaccines will simplify supply and booking and will help to ensure a good balance between achieving rapid and long-lasting protection
  • For those under 18 who are not in a high-risk group, a 12-week interval is recommended. This longer interval reflects strong evidence of high levels of protection against severe disease from the first dose, although it could be shortened to 8 weeks in periods of high incidence or where there was concern about vaccine effectiveness (for example, a new variant). Emerging evidence also suggests that countries with longer schedules (8–12 weeks) may have a lower rate of myocarditis after the second dose. Although this latter evidence is limited, the JCVI has taken a precautionary approach to mitigate the very rare risk of post-vaccine myocarditis
  • The main exception to the 8-week lower interval would be those about to commence immunosuppressive treatment. In these individuals, the minimal intervals (21 days for Pfizer BioNTech vaccine or 28 days for Moderna and AstraZeneca vaccines) may be followed to ensure that the vaccine is given whilst their immune system is better able to respond.

Booster programme

  • To maintain high levels of protection against severe COVID-19 disease, and specifically, hospitalisation and death through the winter, the JCVI initially advised that booster vaccines be offered to those most at risk from serious disease, and who were vaccinated during Phase 1 of the vaccine programme. However, after extending the booster dose offer to all aged 40–49 years, on 29 November 2021, in response to the emergence of the Omicron variant, the JCVI advised accelerating the booster programme and offering a booster dose to all adults aged from 18 years. Booster vaccination should not be given within 3 months of completion of the primary course
  • Booster doses for those under 18 are currently only indicated for individuals aged 16 years and over who: have underlying health conditions that put them at higher risk of severe COVID-19 (as set out in the Green Book COVID-19 chapter), are carers, or who are household contacts of immunosuppressed individuals of any age
  • Further information about the booster programme is available in the JCVI statements and also in the COVID-19 chapter of the Green Book.

Vaccine to be used for booster doses

  • The JCVI has advised that a full dose (30 mcg) of Pfizer BioNTech vaccine or a half dose (50 mcg) of the Moderna vaccine should be offered as a booster dose. These two vaccines should be used with equal preference in the COVID-19 booster programme as both vaccines have been shown to substantially increase antibody levels when offered as a booster dose. A half dose of Moderna is advised for the booster dose as it is expected to have a lower rate of side effects (including myocarditis) than a full dose
  • Where both Pfizer and Moderna vaccines are not clinically suitable, vaccination with the AstraZeneca vaccine may be considered for those who received at least one dose of this vaccine previously. In exceptional circumstances, persons aged 40 years or over who received a mRNA COVID-19 vaccine previously may be offered a booster dose of AstraZeneca vaccine following a decision by a health professional on a case-by-case basis.

For recommendations on exceptional circumstances in which a different second vaccine to the first can be given, such as for housebound patients or care home residents, and individuals who experience severe adverse reactions after the first dose, refer to the full guideline.

For recommendations on administration of the COVID-19 vaccine, view the full summary at guidelines.co.uk/455707.article

Administration of COVID-19 vaccine

Infection prevention and control

  • All those attending for vaccination and those delivering vaccination should wear appropriate personal protective equipment as described in the infection prevention and control advice current at the time of administering the vaccine
  • Hand hygiene is critical to prevent the spread of infection and hands should be cleaned with alcohol-based gel or soap and water before vaccine preparation, between patients, and so on. Those preparing and administering the vaccine should maintain good hand hygiene throughout and should take care not to touch the vial bung with their fingers.

Injection technique

  • COVID-19 vaccines should be administered by intramuscular injection, preferably into the deltoid muscle of the upper arm
  • Individuals who have minimal muscle mass in the deltoid area of the upper arm, or a particular reason to avoid immunisation in the deltoid muscle, can be given their vaccine in the vastus lateralis muscle in the thigh if necessary
  • The area for injection should be clearly visible and accessible. Garments with long or tight sleeves may need to be removed. The injection site does not need to be cleaned unless visibly dirty. If cleaning is required, water should be used, and the area dried with a gauze swab. It is not necessary to disinfect the skin
  • Insert the needle into the injection site far enough to ensure it will deliver the vaccine into the muscle and depress the plunger. There is no need to pull back on the plunger (aspirate) before the plunger is depressed to release the vaccine into the muscle because there are no large blood vessels at the recommended injection sites
  • Ensure the full dose is administered, as a partial dose will not evoke a full immune response. Remove the needle and if there is any visible blood at the injection site, the patient can apply pressure to the site with a piece of gauze or cotton wool.

For information on administering COVID-19 vaccine to individuals with bleeding disorder and/or taking anticoagulants, refer the full guideline.

Timing of administration of COVID-19 vaccine to individuals who are immunosuppressed

  • Individuals who have immunosuppression and HIV infection (regardless of CD4 count) should be given COVID-19 vaccine in accordance with the recommendations and contraindications stated in the COVID-19 vaccine PGDs and Protocols and Green Book COVID-19 chapter
  • Individuals with immunosuppression may not make a full immune response to vaccination
  • As there is limited evidence on response in immunosuppressed individuals there is also very little evidence upon which to base advice on the optimal timing of delivery. However, one study suggested immune responses were better in patients with cancer who received their chemotherapy at least 2 weeks earlier
  • Specialists may advise their patients based on their knowledge and understanding of their immune status and likely immune response to vaccination but should also consider the risk from COVID-19 and the patient’s likelihood of exposure
  • The small number of patients who are about to receive planned immunosuppressive therapy should be considered for vaccination prior to commencing therapy (ideally at least 2 weeks before), when their immune system is better able to make a response. Where possible, it would also be preferable for the two-dose schedule to be completed prior to commencing immunosuppression. This would entail offering the second dose at the recommended minimum for that vaccine (3 or 4 weeks from the first dose) to provide maximum benefit that may not be received if the second dose was given during the period of immunosuppression. Any decision to defer immunosuppressive therapy or to delay possible benefit from vaccination until after therapy should not be taken without due consideration of the risks from COVID-19 and from their underlying condition
  • Individuals aged 12 years or over who are household contacts of immunosuppressed patients of any age should be offered vaccine to reduce the risks of exposure
  • As some individuals who are immunosuppressed due to underlying health conditions or medical treatment may not mount a full immune response to COVID-19 vaccination, JCVI have recommended a third primary dose vaccination for patients who were severely immunosuppressed at or around the time of their first or second primary COVID-19 vaccination
  • The specialist involved in the care of patients with immunosuppression should be involved in advising on the timing of a third dose. If a third primary dose is required, ideally, it should be given at least 8 weeks after the second dose with special attention paid to the timing of any planned or current immunosuppressive therapy. Where possible the third dose should be delayed until 2 weeks after the period of immunosuppression, in addition to the time period for clearance of the therapeutic agent. If not possible, consideration should be given to vaccination during a treatment ‘holiday’ or when the degree of immunosuppression is at a minimum
  • For those aged over 18 years, the JCVI advises a preference for mRNA vaccines (Pfizer BioNTech or Moderna) for the third primary dose. Pfizer BioNTech is preferred for 12–17-year-olds. AstraZeneca COVID-19 vaccine is an option for individuals who have received this vaccine previously where this would help to improve implementation. In exceptional circumstances, people aged 40 years or over who received a mRNA COVID-19 vaccine previously may be offered a third dose of AstraZeneca vaccine following a decision by a health professional on a case-by-case basis
  • Those aged 16 years and above in this group will also require a booster dose to extend protection from their primary course. Following the recognition of the Omicron variant, the JCVI has now advised that a reinforcing dose should be offered from 3 months after the third dose. Those who have not yet received their third dose may be given their third dose now to avoid further delay. A further booster dose can be given in 3 months, in line with the clinical advice on optimal timing. A decision on boosting those aged 12–15 years in this group is under consideration by the JCVI.

Period of observation following immunisation with COVID-19 vaccine

  • Following COVID-19 vaccine administration, individuals should be observed for any immediate reactions whilst they are receiving any verbal post-vaccination information (such as possible reactions and what, if anything, to do about these). They, or their carers, should also be informed where they can obtain further advice if they require it following vaccination
  • According to the summaries of product characteristics, it is recommended that all recipients of the Pfizer BioNTech and Moderna vaccines are kept for observation and monitored for a minimum of 15 minutes. In recognition of the need to accelerate delivery of the programme in response to the emergence of the Omicron variant, the UK Chief Medical Officers have recommended suspension of this requirement. This temporary suspension in individuals without a history of allergy has also been agreed by the Commission on Human Medicines
  • The MHRA will continue to closely monitor anaphylaxis post-COVID-19 vaccination. Reporting of adverse events via the Yellow Card Scheme is strongly encouraged
  • In some settings, for example domiciliary vaccination, this may require a responsible adult to be present for at least 15 minutes after vaccination
  • Patients with a personal history of allergy will require a period of observation following vaccination (either 15 or 30 minutes depending on their clinical history). These individuals should be managed as described in table 5 of the Green Book COVID-19 chapter. No specific management is required for patients with a family history of allergies.
  • There is no requirement for 15 minutes observation following the AstraZeneca vaccine. However, as fainting can occur following vaccination, all those vaccinated with any of the COVID-19 vaccines should either be driven by someone else or should not drive for 15 minutes after vaccination.

Advice to vaccine recipients following immunisation with COVID-19 vaccine

Thrombosis with thrombocytopenia syndrome 

  • A rare condition involving serious thromboembolic events accompanied by thrombocytopaenia, has been reported after AstraZeneca (Vaxzevria) vaccination
  • Vaccinated individuals should be advised to seek immediate medical attention if they develop new symptoms from around 4 days to 4 weeks after vaccination such as:
    • new onset of severe headache, which is getting worse and does not respond to simple painkillers
    • an unusual headache that seems worse when lying down or bending over, or may be accompanied by blurred vision, nausea and vomiting, difficulty with speech, weakness, drowsiness, confusion, or seizures
    • new onset of unexplained pinprick bruising or bleeding
    • shortness of breath, chest pain, leg swelling, or persistent abdominal pain.

Myocarditis and pericarditis

  • A number of cases of myocarditis (inflammation of the heart muscle) and pericarditis (inflammation of the pericardium) have been reported in people who have recieved the Pfizer BioNTech and Moderna COVID-19 vaccines. The reported rate appears to be highest in those under 25 years of age and in males, and after the second dose. Onset is within a few days of vaccination and most cases are mild, recovering within a short time following standard treatment and rest without any sequalae
  • Vaccinated individuals should be advised to seek immediate medical attention should they experience new onset of chest pain, shortness of breath, palpitations, or arrhythmias
  • As the mechanism of action and risk of recurrence of myocarditis and pericarditis are being investigated, the current advice is that an individual’s second or subsequent doses should be deferred pending further investigation.

Guillain-Barré syndrome

  • Very rare reports have been received of Guillain-Barré syndrome (GBS) following COVID-19 vaccination, so healthcare professionals should be alert to the signs and symptoms of GBS to ensure correct diagnosis and to rule out other causes, in order to initiate adequate supportive care and treatment and to rule out other causes
  • Individuals who have a history of GBS should be vaccinated as recommended for their age and underlying risk status 
  • As there is no evidence to suggest that having had a prior diagnosis of GBS predisposes an individual to further episodes, in those who are diagnosed with GBS after the first dose of vaccine, the balance of risk benefit is in favour of completing a full COVID-19 vaccination schedule. On a precautionary basis, however, where GBS occurs within 6 weeks of an AstraZeneca vaccine, the Pfizer BioNTech or Moderna mRNA COVID-19 vaccines are preferred for any future doses. Where GBS occurs following either of the mRNA vaccines (Pfizer BioNTech or Moderna), further vaccination can proceed as normal, once recovered.

Additional advice for vaccine recipients

  • Vaccine recipients should also be advised that it may take a few weeks for protection from their COVID-19 vaccination to develop and that they should continue to follow advice current at the time regarding practicing social distancing, wearing a facemask, and washing their hands thoroughly and frequently
  • Vaccinees should also be advised to follow the current advice on testing and self-isolation if they develop any coronavirus symptoms or undergo regular testing as a health or social care worker. Vaccination will not affect testing. The lateral flow device (LFD) test detects a different protein of the virus than the one encoded in the vaccine, and the polymerase chain reaction (PCR) test detects different genes of the virus than the one included in the vaccine
  • As no vaccine is completely effective, some people may still become infected with COVID-19 despite having been vaccinated (although this should be less severe)
  • The vaccine cannot cause COVID-19 infection.

For information on COVID-19 vaccine and clinical trial participants, surveillance of COVID-19 cases in vaccinated individuals, and adverse reactions following vaccination (including reporting adverse reactions), refer to the full guideline. 

COVID-19 vaccine contraindications and precautions

  • Relative contraindications to receiving a COVID-19 vaccine are:
    • individuals who have had a previous systemic anaphylaxis reaction to a COVID-19 vaccine
    • individuals with a prior allergic reaction to any component (excipient) of the COVID-19 vaccine, for example polyethylene glycol
  • The COVID-19 chapter of the Green Book provides full details about the contraindications and precautions to COVID-19 vaccine. Everyone involved in the COVID-19 vaccination programme should ensure they have read the latest online version of this Green Book chapter so that they are familiar with all the contraindications and precautions to the COVID-19 vaccines. Where there is any doubt as to whether the vaccine can be given, appropriate advice should be sought from the relevant specialist, or from the local immunisation team or health protection team.

Thrombosis and thrombocytopenia syndrome

  • Thrombocytopenia presents with unusual venous thrombosis, including cerebral venous sinus thrombosis, portal vein thrombosis, and sometimes arterial thrombosis, with low platelet count and high D-dimer measurements. The condition has similarities to heparin-induced thrombocytopenia and thrombosis (HITT or HIT type 2) and patients usually have positive antibody to platelet factor 4. The majority of the events have occurred between 5 and 16 days following vaccination
  • Individuals who experience a clotting episode with concomitant thrombocytopaenia following the first dose of AstraZeneca vaccine should be properly assessed. If they are considered to have the reported condition, further vaccination should be deferred until their clotting has completely stabilised. Current evidence supports a decision to complete the primary course or boost patients with a history of thrombocytopenia syndrome with an mRNA vaccine, provided at least 12 weeks has elapsed from the implicated dose.
  • Individuals who have received the first dose of AstraZeneca vaccine without developing this rare condition are advised to receive the second dose of the same vaccine at the currently recommended interval. To date, there is no signal of an increased risk of this condition after the second dose and the rate of other reactions is lower at the second dose than after the first dose of this vaccine. Using an alternative product for the second dose is more likely to lead to common side effects.
  • Caution should also be used when vaccinating individuals who have a history of a previous episode of HITT or HIT type 2
  • UK Health Security Agency’s Information for healthcare professionals on COVID-19 Vaccine AstraZeneca advises that, as a precautionary measure, administration of the AstraZeneca vaccine in patients with a history of HITT or HIT type 2 should only be considered when the benefit outweighs any potential risks
  • The contraindications and precautions to the AstraZeneca vaccine, including the age group recommendations for this vaccine, are detailed in the COVID-19 chapter of the Green Book
  • Further detailed information is also available in UKHSA’sInformation for healthcare professionals on blood clotting following COVID-19 vaccination document and a COVID-19 vaccination and blood clotting leaflet is available for patients.

Capillary leak syndrome

  • A small number of cases of capillary leak syndrome have been reported across Europe within 4 days of AstraZeneca vaccination. Around half of those affected had a history of capillary leak syndrome
  • Initial symptoms may include tiredness, nausea, abdominal pain, extreme thirst, and sudden increase in body weight. Complications can include general swelling, compartment syndrome, kidney failure, and stroke
  • Individuals with a history of capillary leak syndrome should be carefully counselled about the risks and benefits of vaccination and may be offered an alternative COVID-19 vaccine (that is, an mRNA vaccine instead of AstraZeneca).

Minor illness at time vaccination due

  • Minor illnesses without fever or systemic upset are not valid reasons to postpone immunisation
  • If an individual is acutely unwell, immunisation may be postponed until they have fully recovered. This is to avoid confusing the differential diagnosis of any acute illness (including COVID-19) by wrongly attributing any signs or symptoms of the illness as being possible reactions to the vaccine.

Vaccination of individuals with a current or previous history of COVID-19 disease

  • People currently unwell and experiencing COVID-19 symptoms should not receive COVID-19 vaccine until they have recovered. This is to avoid wrongly attributing any new symptom or the progression of symptoms to the vaccine (and to prevent infecting anyone else in the vaccination centre)
  • Vaccination of individuals who may be infected or asymptomatic or incubating COVID-19 infection is unlikely to have a detrimental effect on the illness. Vaccination should be deferred in those with confirmed infection to avoid confusing the differential diagnosis
  • As deterioration in some people with COVID-19 can occur up to 2 weeks after infection, ideally vaccination of adults and high-risk children should be deferred until they have recovered to around 4 weeks after onset of symptoms or 4 weeks from the first confirmed positive test in those who are asymptomatic
  • There is no convincing evidence of any safety concerns from vaccinating individuals with a past history of COVID-19 infection, or with detectable COVID-19 antibody, so people who have had COVID-19 disease (whether confirmed or suspected) can still receive COVID-19 vaccine
  • Children or adults who have tested positive for COVID-19 infection in the previous 28 days and who require other vaccines (such as DTaP/IPV/Hib/HepB-containing vaccines) can receive these vaccines once they have recovered and have completed the required isolation period for COVID-19. If they fulfil these two conditions, they do not have to wait 28 days but the parent/carer who brings them for vaccination would need to ensure they are following current COVID-19 guidance and not attend if they are symptomatic or self-isolating
  • Recent vaccination with other vaccines such as MMR and Td/IPV-containing vaccines do not affect testing for COVID-19 infection. The LFD test looks to detect a protein of the SARS-CoV-2 virus and the PCR test looks for genes from the SARS-CoV-2 virus. 

Vaccination of people experiencing prolonged COVID-19 symptoms (‘long COVID’)

  • Having prolonged COVID-19 symptoms is not a contraindication to receiving COVID-19 vaccine but if the patient is seriously debilitated, still under active investigation, or has evidence of recent deterioration, deferral of vaccination may be considered to avoid incorrect attribution of any change in the person’s underlying condition to the vaccine.

Treatments for COVID-19 disease (for example monoclonal antibody, steroids, or antiviral medicines) and vaccine administration

  • Antiviral medicines prevent further replication of viruses. As none of the currently authorised COVID-19 vaccines contain live replicating virus, response to COVID-19 vaccine will not be affected by prior or recent receipt of anti-viral medication
  • Therefore, none of these treatments would contraindicate COVID-19 vaccine. However, it is recommended that following infection, ideally vaccination of adults and children aged 12–17 years should be deferred to around 4 weeks after onset of symptoms or 4 weeks from the first confirmed positive specimen in those who are asymptomatic and for 12 weeks for those under 18 years not in high-risk groups (see section on vaccination of individuals with a current or previous history of COVID-19 disease).

Co-administration of COVID-19 vaccine with other inactivated or live vaccines

  • First principles would suggest that interference between inactivated vaccines with different antigenic content is likely to be limited
  • Based on experience with other vaccines, any potential interference is most likely to result in a slightly attenuated (weaker) immune response to one of the vaccines. There is no evidence of any safety concerns, although it may make the attribution of any adverse events more difficult
  • As the Pfizer BioNTech, AstraZeneca, and Moderna COVID-19 vaccines are considered inactivated, where individuals in an eligible cohort present having recently received another inactivated or live vaccine, COVID-19 vaccination should still be given. The same applies for most other live and inactivated vaccines where COVID-19 vaccination has been received first or where a patient presents requiring two vaccines. It is generally better for vaccination to proceed to avoid any further delay in protection and to avoid the risk of the patient not returning for a later appointment. The only exceptions to this are the shingles vaccines, where a 7-day interval should ideally be observed
  • Where co-administration does occur, patients should be informed about the likely timing of potential adverse events relating to each vaccine. 

Pregnant women

  • Although clinical trials on the use of COVID-19 vaccines during pregnancy are not advanced, the available data do not indicate any harm to pregnancy. The JCVI has therefore advised that women who are pregnant should be offered vaccination at the same time as non-pregnant women, based on their age and risk status
  • Because of more extensive experience with the Pfizer BioNTech and Moderna vaccines in pregnancy, these two vaccines are the preferred vaccines to offer to pregnant women aged 18 years and over. Pregnant women under 18 years of age should be offered the Pfizer BioNTech vaccine as that is the vaccine currently recommended for this age group. Pregnant women who have already received a dose of AstraZeneca vaccine can complete with the same vaccine or with an mRNA vaccine (provided there are no contraindications)
  • Routine questioning about last menstrual period and/or pregnancy testing is not required before offering COVID-19 vaccine. Women who are planning pregnancy or in the immediate postpartum can be vaccinated with a suitable product for their age and risk status
  • If a woman finds out she is pregnant after she has started a course of COVID-19 vaccine, she should complete vaccination during pregnancy at the recommended interval
  • Termination of pregnancy following inadvertent immunisation should not be recommended
  • Surveillance of inadvertent administration of COVID-19 vaccines in pregnancy (where the woman did not know she was pregnant at the time of vaccination) is being conducted for the UK by the UKHSA Immunisation and Vaccine Preventable Diseases Division. If a pregnant woman is inadvertently given COVID-19 vaccine, from the first day of her last menstrual period to any time in pregnancy, this should be reported. Women who are inadvertently vaccinated in early pregnancy should be offered the second dose of the same product
  • Further information about the safety of COVID-19 vaccines when given in pregnancy is available. Both the Royal College of Obstetricians and Gynaecologists and the Royal College of Midwives websites provide useful information and guidance about the COVID-19 vaccine


  • There is no known risk associated with giving non-live vaccines whilst breastfeeding
  • Breastfeeding women may be offered vaccination with any suitable COVID-19 vaccine
  • The developmental and health benefits of breastfeeding should be considered along with the woman’s clinical need for immunisation against COVID-19, and at the same time, the woman should be informed about the absence of safety data for the vaccine in breastfeeding women.

Children and young people

  • Following careful consideration of the risks and benefits of vaccinating children and young people aged 12–17 years, the JCVI recommended two doses of vaccine for two groups which are:
    • children and young people aged 12 years and over with specific underlying health conditions that put them at risk of serious COVID-19—these conditions are listed in the Green Book COVID-19 chapter and in the JCVI statement
    • children and young people aged 12 years and over who are household contacts of immunosuppressed individuals those aged 12 years and above who expect to share living accommodation on most days (and therefore for whom continuing close contact is unavoidable) with individuals of any age who are immunosuppressed
  • The JCVI has also recommended that all 16–17-year-olds should be offered a first dose of the Pfizer BioNTech vaccine. This was followed by a further JCVI recommendation on 15 November 2021 that they should be offered a second dose after an interval of 12 weeks
  • On 13 September 2021, the UK Chief Medical Officers recommended that all young people aged 12–15 years be offered a first dose of COVID-19 vaccine. On 29 November 2021, the JCVI recommended that all young people in this age group be offered a second dose 12 weeks from the first dose
  • Currently, the Pfizer BioNTech vaccine is the only vaccine recommended to be given to children and young people less than 18 years of age. Although the Moderna vaccine is also approved in children from 12 years, the Pfizer vaccine is currently preferred due to a lower reported rate of myocarditis. Young people who have already received a first dose of AstraZeneca vaccine can complete with the same vaccine or with an mRNA vaccine (provided there are no contraindications).

For information on vaccination of children and young people who have recently had SARS-CoV-2 infection, adverse reactions, legal aspects of vaccine administration, inadvertent vaccine administration errors, and storage and preparation of the COVID-19 vaccines, refer to the full guideline.


Want to learn more about this guideline?

GinP G Logo small

Read the related Guidelines in Practice article, COVID-19 vaccination programme: practice pointers for primary care.

Full guideline:

UK Health Security Agency. COVID-19 vaccination programme: information for healthcare practitioners. Version 3.11. December 2021. Available at: gov.uk/government/publications/covid-19-vaccination-programme-guidance-for-healthcare-practitioners

Contains public sector information licensed under the Open Government Licence v3.0.

Published date: 27 November 2020.

Last updated: 21 December 2021.