Can I have a COVID-19 vaccination before a CT scan?

It is important to advise your oncologist or radiographer if you have received the COVID-19 vaccine recently. This is because the vaccine can cause the lymph nodes in your armpit and neck to swell which can be detected by CT scans used to diagnose and monitor cancers.

This is particularly detected by FDG PET/CT scans, in which you are given a contrast medium containing a type of radioactive sugar that is taken up by active cells. When an immune response to a vaccine takes place, the cells in the lymph nodes near the injection site become very active and take up a lot of this sugar. Depending on the type of cancer, you may be able to request the injection on the opposite side to your tumour. If possible, have the vaccination at least 2 weeks before a scheduled scan or as soon as you can afterwards. Do not delay any treatment.

Can I receive the COVID-19 vaccine even though I have a compromised immune system or am receiving treatment for cancer?

Many people take medication that suppresses their immune system, especially for the treatment of cancer, severe asthma, autoimmune diseases or following organ transplantation, or have medical conditions that can affect the immune system, such as HIV infection or kidney failure.

These conditions put you at increased risk from COVID-19, and although you may not respond as strongly to the vaccine as someone with a fully functioning immune system, it is safe for you received COVID-19 vaccine and it will provide some protection against COVID-19, particularly against severe and life-threatening disease.

It is important and safe for those receiving active treatment with immunosuppressive medications to have the COVID-19 vaccine. If you are severely immunocompromised, it is recommended to talk to your GP or specialist to discuss the optimal timing for vaccination before the vaccine appointment. Ideally, vaccination should be conducted prior to any planned immunosuppression.

It is also important for the people around you, in your household, to have the vaccine when it is offered to them to widen your protection.


For information about Cancer care and COVID-19 vaccine see Te Aho o Te Kahu (Cancer Control Agency) information here.

Is the Comirnaty vaccine safe and effective for people living with HIV?

The vaccine has been through rigorous testing to ensure safety and efficacy and is now being used widely overseas without any serious concerns appearing. People with HIV were included in clinical trials though efficacy and safety data specific to this group are not yet available.

With some vaccines people living with HIV can produce a weaker immune response. People living with HIV are encouraged to be vaccinated. People with HIV were included in clinical trials for the Pfizer vaccine, although the data specific to this group is not yet available there are no safety concerns.

Based on what we know about people living with HIV and their response to other vaccines:

  • those with a suppressed viral load are likely to have some protection from the COVID-19 vaccine
  • they may have a weaker response to some vaccines, including the COVID-19 vaccine

For people who are newly diagnosed and starting HIV treatment are advised to take advice from their specialist about the timing of their vaccination. Any medication being taken for HIV is not expected to change how effectiveness of the COVID-19 vaccine. The vaccine will not affect HIV medications.​

Will children receive a COVID-19 vaccination?

Medsafe has not approved a COVID-19 vaccine for use in children under the age of 16 as yet.

Further research with vaccine trials enrolling children is underway overseas. Initial data in 12-15 year-olds looks promising, with excellent efficacy and a similar safety profile to that seen in adults. Read this Stuff article with IMAC’s Dr Emma Best offering some helpful ideas on how to approach the topic of COVID-19 and vaccines with children.

Can a person who is currently sick with COVID-19 receive a vaccine?

Internationally, guidance states that people who are currently isolating or experiencing symptoms of COVID-19 should not be vaccinated until they have recovered and met the criteria to stop isolating.

If you had the virus and recovered, will you still be able to or need to get the vaccine?

Vaccination is being offered to people who have and have not had SARS-CoV-2 infection previously.

Data from clinical trials and from countries with a lot of COVID-19 cases have shown the vaccines to be safe and effective in this group of people. It is expected that the vaccine will boost the immune response and provide good protection for those who have previously had SARS-CoV-2 infection. Start your vaccination course at least 4 weeks after you have recovered. For more information, please click here.

Can COVID-19 vaccines be safely given to frail and elderly people?

There are no safety concerns around giving COVID-19 vaccine to older and frail adults. Multiple COVID-19 vaccine candidates have shown to protect against severe disease in older age groups.

A single dose of COVID-19 vaccine substantially reduced (over 70%) the risk of COVID-19-related hospitalisation in elderly, frail patients with extensive co-existing conditions in the UK. By 2 weeks after the second dose effectiveness against symptomatic COVID-19 in adults aged over 70 years was 85-93%. This is important, as increasing age is a risk factor for severe COVID-19.

Following reports of deaths of frail, elderly adults in residential care facilities after COVID-19 vaccination, independent reviews by both the CDC and the WHO concluded that the mortality rate in this population is typically high and a substantial number of deaths will occur coincidentally following vaccination. For further information, click here.

COVID-19 vaccines in pregnancy and breastfeeding

Pregnant people are encouraged to be vaccinated against COVID-19 at any stage of pregnancy.

In pregnancy, the risk of severe COVID-19 complications is much higher than in people who are not pregnant. The updated recommendation aligns with recommendations in other countries and is based on international evidence from a large number of people who have already received mRNA COVID vaccines when pregnant and no additional safety concerns have been shown. There is also increasing evidence that antibodies made by the mother after vaccination are shared with the baby in the cord blood that are likely to also protect her newborn baby against COVID-19.

As with all vaccines on the New Zealand Immunisation Schedule, there are no safety concerns about giving mRNA COVID-19 vaccine to women who are breastfeeding and by being vaccinated, mothers can provide some protection against COVID-19 for their babies in breastmilk.

Please refer to the Immunisation Advisory Centre's COVID-19 vaccination in pregnancy fact sheet for more information.

Reference

Shimabukuro TT, Kim SY, Myers TR, et al. Preliminary Findings of mRNA Covid-19 Vaccine Safety in Pregnant Persons. N Engl J Med. 2021 DOI: 10.1056/NEJMoa21049