What is currently known about myocarditis and the Comirnaty vaccine?

‘In April, reports of myocarditis being diagnosed in the few days following receipt of Comirnaty vaccine, particularly following the second dose, started to appear in countries using this vaccine in younger adults from 16 years (Israel and USA). ‘

In April, reports of myocarditis being diagnosed in the few days following receipt of Comirnaty vaccine, particularly following the second dose, started to appear in countries using this vaccine in younger adults from 16 years (Israel and USA). The vast majority of the cases of myocarditis reported to US CDC (to the end of May) following Comirinaty vaccination have been discharged from hospital (95%) with most fully recovered (81%). CDC is currently reviewing data from the Vaccine Safety Datalink network, which is able to directly compare rates of various conditions occurring with and without receipt of Comirinaty vaccine in large numbers of people, to evaluate the relative incidence and gather information about severity of myocarditis in vaccinated and unvaccinated young adults.  

Myocarditis and pericarditis are uncommon conditions, usually thought to be related to viral infection leading to inflammation of the heart muscle or the tissue surrounding the heart. Chest pain is the most common symptom. Diagnosis is based on elevated levels of cardiac enzymes in blood tests, and by electrocardiogram and echocardiogram tests. Rates of incidence vary between populations and by gender and age; for example, the incidence in adolescent males aged 14 to 18 years is significantly higher than in females. 

MedSafe is closely monitoring for any reports of myocarditis following COVID-19 vaccination in New Zealand. For further information please refer to the WHO’s statement.

COVID-19 vaccine may cause swelling of local lymph nodes. Does this affect mammogram results?

When you attend a mammogram, it is recommended that you mention to your doctor or radiographer that you have had a COVID-19 vaccination recently.

This is because occasionally the vaccine can cause swelling of the lymph nodes in the arm pit near to the injection-site. This usually settles after a few days after vaccination but may be detectable on a mammogram for up to a few weeks. In this case, it is advised to monitor such lymph node changes for at least 6 weeks after vaccination. You do not need to delay your vaccination or your mammogram.

Click this link for further information from BreastScreen Aotearoa.

Can mRNA COVID-19 vaccine affect fertility or affect future babies?

There is no biologically plausible reason why this vaccine could have any effect on our genes or fertility.

Upon injection, the lipid nanoparticle containing the mRNA is taken up by specialised cells (dendritic cells) at the injection site in the arm. These cells use the instructions from the vaccine mRNA to make only the SARS-CoV-2 spike protein and the mRNA degrades rapidly. The mRNA from the vaccine does not enter the nucleus of any cells. Furthermore, no components of the vaccine or the spike protein produced reach the ovaries or the testes. More information about how this concern arose can be found here.

How long will COVID-19 vaccine immunity (i.e. protection from the COVID-19 disease) last?

We would expect COVID-19 vaccines to provide protection for longer than 2 months, although exactly how long for, remains unknown at this stage. This is because not enough time has passed since the clinical trials started to be able to accurately answer this.

We know that the Pfizer/BioNTech COVID-19 vaccine lasts for AT LEAST two months, because data supporting this has been reviewed by Medsafe. As part of the conditional approval of the Pfizer/BioNTech COVID-19 vaccine, more data is to be provided as it becomes available. It is anticipated that further data will be provided on durability of the immune response post vaccination in coming months.

If a person is vaccinated against COVID-19, will they still be able to spread the virus to susceptible people?

An ideal vaccine stops everyone from carrying and passing on the infection as well as protecting them from becoming seriously ill. It is currently unclear whether COVID-19 vaccines only protect against symptomatic and severe disease, or if they can also stop all infection, including asymptomatic infection (i.e. showing no symptoms).

If the vaccine is only able to stop the symptoms of the disease, but unable to stop the virus from infecting us and reproducing, then the virus may still be able to be spread. Even in this case, by reducing the number of people with symptoms will help to reduce spread of the virus because fewer people will be coughing large quantities of virus on others. However, this possible limitation of the vaccine highlights the importance of continuing to follow public health advice such as hand washing and isolating if unwell, even post vaccination. For more information, please click here.

Recently published data from Israel showed that its mass COVID-19 vaccination campaign (using the Pfizer vaccine) was working well with two doses cutting symptomatic cases by 94% across all age groups. Data reported by the CDC in the US has also shown that mRNA COVID-19 vaccines were 90% effective in health care workers against SARS-CoV-2 infection (with and without symptoms).

What is the priority - an influenza vaccine or a COVID-19 vaccine?

The COVID-19 mRNA vaccine two-dose schedule should take priority over influenza (flu) vaccine.

The flu vaccine can be administered two weeks after the second dose of COVID-19 vaccine, which is given at least 21 days after the first dose. 

How should we space MMR, influenza and COVID-19 vaccination?

Please continue to allow a four-week gap when giving the MMR vaccine before the COVID-19 vaccine where possible. However, the gap can be reduced to two weeks when giving the MMR vaccine after the second dose of the COVID-19 vaccine. Complete both doses of the COVID-19 vaccine, 21 days apart, before giving another vaccine.

Please continue to allow a two-week gap between the COVID-19 vaccine and influenza vaccine where possible, regardless of the order they’re given.

Having a gap between the different types of vaccinations makes it easier to judge which vaccine may be responsible for any side effects. Note that there are no clinical safety concerns should the gap between vaccines be less than the recommendations above. Do not delay vaccination if such a gap is not possible.

The MMR and influenza vaccines can be given at the same time.

The Ministry of Health has put together a flowchart for healthcare providers managing MMR and influenza vaccinations around COVID-19.

Can other vaccines be administered with a COVID-19 vaccine?

Currently Medsafe advice is only available for the mRNA vaccine from Pfizer/BioNTech (Comirnaty™) vaccine.

A two-week gap is generally recommended after any non-live vaccine, including influenza, and the Comirnaty mRNA COVID-19 vaccine. If a live vaccine, such as MMR, varicella and zoster vaccine has been given, then a four-week gap is generally recommended before Comirnaty. If Comirnaty, is given first, then maintain a two week gap before any other vaccines. Do not delay if a gap between these vaccines is not practicable.

Please note that two doses of the mRNA vaccine are required, given at least 21-days apart. These recommendations are continually being reviewed.

What is the acceptable timeframe between the first and second doses of the Comirnaty vaccine?

To be fully immunised with Comirnaty requires two doses given at least 21 days apart.

Vaccinators are advised not to give the second dose earlier than this, and while longer spacing is acceptable, the recommended spacing is for the second dose to be given as close after 21 days as possible.

What is the guidance around receiving a COVID-19 vaccine and having a general anaesthetic?

Based on first principles and our experience with other vaccines, there is no expectation that an anaesthetic would affect the safety or immunogenicity of the mRNA COVID-19 vaccine.

The general recommendation when planning vaccination with any vaccine is explained in Section 3.1.3 in the Immunisation Handbook 2020

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.​

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