Covid-19 (SARS-CoV-2)

Some information about the virus and the vaccination for Shore Birth clients

Can you remember March 2020 when we had our first confirmed case of Covid-19 in New Zealand? It was a scary time!

We put up some information up on our website in 2020 but we now know so much more about the virus. We have decided to leave this bulletin up in the meantime because not many of us have studied cell biology and it provides a clear explanation of Covid-19 and the early vaccines.

What is a virus?

A virus is a micro-organism or tiny germ smaller than a bacteria that can’t grow or reproduce apart from in a living cell.  Viruses are the most abundant biological entity on the earth and outnumber all other life forms on earth combined.  Billions of them waft down on us every day!  Viruses are very simple organisms made of a protein coat and a string of genetic material which is either DNA (deoxyribonucleic acid) or RNA (ribonucleic acid).  A virus invades a living cell and uses the machinery of the cell to keep itself alive and reproduce itself.

What are the coronaviruses?

Coronaviruses are a large family of viruses that cause illness ranging from a common cold to severe illness.  They get their name from the Latin “coronum” meaning crown or wreath as they have a crown-like appearance when observed with an electron microscope.

What is Covid-19?

Covid-19 is a new strain of coronavirus not previously seen in humans.  It contains a single strand of RNA surrounded by a protein coat.  One of the proteins on that coat is called the “spike protein” and it is a bit like a foot which the virus uses to bind itself to a human cell in order to invade it.  If the virus can’t bind to the human cell, it can’t invade the cell and therefore this has been a key target in the development of vaccines against Covid-19.

What are the vaccines and do they differ?

There have been many vaccines developed throughout the world but the main vaccines you will have heard about being used in NZ, Australia, the UK and the USA are the Pfizer-BioNtech and Moderna vaccines which are mRNA-based vaccines and the Oxford Astra Zenica and Johnson and Johnson (J&J) vaccines which are adenovirus-based vaccines. 

So, yes, each vaccine is different but they can be grouped together by the way they have been developed and work.   

In New Zealand, we are currently being offered immunisation with the Pfizer-BioNtech vaccine.  This is an mRNA vaccine which targets the spike protein that Covid-19 uses to attach itself to a human cell in order to infect it, as discussed above.

Vaccines traditionally contain either a weakened form of a virus or a purified signature protein of a virus which train the immune system to recognise the disease, should it attack.  However, mRNA vaccines are different.  You don’t receive a part of the virus at all but instead cell instructions on how to make the spike protein which then produces an immune response.  The immune system makes powerful antibodies against Covid-19 that can then neutralise the real virus if you are exposed.

What is mRNA?

Proteins are made of building blocks called amino acids.  Messenger RNA or mRNA is a single stranded RNA molecule which carries the genetic information (or blueprint if you like) telling the ribosomes (protein factories) in the cytoplasm (jelly of a cell) how to make amino acids.  mRNA Covid-19 vaccines therefore guide the muscle cells to produce the amino acids which build the Covid-19 spike protein.

Can you catch Covid-19 from the vaccine?

No, this is physically impossible.

Can Covid-19 vaccine interfere with your DNA?

No, our DNA is stored inside the nucleus of a cell, not the cytoplasm where proteins are made.

How effective is the Pfizer-BioNtech vaccine?

For this vaccine, you receive 2 doses, 21 days apart.  You begin to have some immunity within 14 days of the first dose (about 80% protection) and full immunity 2 weeks after the second dose – 95% protection. Boosters are offered 6 monthly at present, or six months after an infection with Covid. This year - April 2024, there is a new booster against the latest strain of Covid which is sneakier at avoiding immunity.

If you are in the unlucky 5% who do get Covid-19, vaccination protects you against severe disease, ICU admission and death from Covid-19. It also greatly reduces the risk of long Covid.

When Covid-19 is circulating in the community, you will still need to socially distance and wear a mask in enclosed spaces.

What side effects occur with the vaccine?

About 80% of people report a sore arm muscle (site pain).

About 50% report fatigue, myalgia (muscle pains), fever and headache – more commonly after the second dose.  This is the body’s immune system producing an immune response to Covid-19 and so it confirms the vaccine is working.

Are there any serious reactions to the vaccine?

There is a very small risk of allergic reaction to the vaccine, called “anaphylaxis”.The quoted risk from reports to date is 11 per million (1 in 90,900). 71% of these reactions occur within 15 minutes of the vaccine and therefore you must be observed for 20-30 minutes after vaccination.  All vaccinators are trained in the treatment of allergy and have the correct anti-allergy medications on hand just in case. 

To put that in perspective, the risk of anaphylaxis to Penicillin is 50-100 per million or 5-9 times more common.

How long does the vaccine protection last?

This is still unknown as we don’t have enough long-term data yet. Immunity begins to wane after six months but researchers are actively working on long acting vaccines.

Is the current vaccine effective against the new variants?

Again, this is emerging research but so far, yes, the Pfizer vaccine is doing well against the variants.  It may be slightly less effective against the B1351 South African variant.

Does the vaccine pose a risk to women trying to become pregnant or getting pregnant in the near future?

No

Should pregnant women receive the Covid-19 vaccine?

Young children and pregnant women were not included in the first trials of Covid-19 vaccine but have been included in current trials so more information is becoming available. 

Data from the US Centre for Disease Control and Prevention (CDC) say that pregnant women can be safely vaccinated with the Pfizer BioNtech and Moderna vaccines for Covid-19. 

Studies of more than 30,000 pregnant women vaccinated in the USA (mainly front-line health workers) showed their rates of side effects from the vaccine or complications of pregnancy are no different and no safety concerns have been identified.    Studies of the cord blood of vaccinated pregnant women show that their babies are born with immunity to Covid-19 in the same way we know that immunising pregnant women against influenza and whooping cough protects the newborn.

Passive protective antibodies have also been detected in the breastmilk of immunised women.

Pregnant women who get Covid-19 are at increased risk for severe disease, ICU admission and death and this is more so for those with diabetes and obesity.  Studies showed that pregnant women who contracted Covid-19 were 20 times more likely to die than pregnant women who did not contract the virus.  In addition, among the mothers who tested positive, 11.5% of their babies also contracted the virus and were more likely to be born preterm.

In a recent updated statement, the RANZCOG (our governing body) recommends that pregnant women be routinely offered the Pfizer mRNA vaccine at any stage of pregnancy.