WHAT are SARS-Cov-2 AND COVID-19?
COVID-19 is a disease caused by a novel coronavirus, SARS-CoV-2, that was first reported in December 2019 in the city of Wuhan, central China.
Coronaviruses are a large group of viruses which affect both mammals and birds, and they cause different diseases depending on the species infected. Human coronaviruses usually cause a mild, common cold-like illness which passes in a few days.
As part of the replication process of viruses, errors or mutations occur which can be minor, but they may also prove to be an advantage to the virus. This may be evident through increased transmissibility, virulence or, in the case of SARS-CoV-2, ability to jump species (a spill-over event). There is relatively recent history of this with two previous extensive outbreaks of coronavirus infections of animal origin spreading to humans - SARS (in 2002-3) and MERS (from 2012 and continuing).
The virus can spread from person to person through:
- Contact with an infectious person through aerosols which are expelled through talking, shouting or singing, particularly in indoor setting with inadequate ventilation (including in the 48 hours before symptoms, if any, appear).
- Contact with droplets from an infected person’s saliva (cough, kiss) or discharge from the nose (sneeze).
- Touching objects or surfaces (like doorknobs or tables) that have droplets from an infected person, and then touching your mouth or face – this is a less common mode of transmission.
WHAT ARE THE SYMPTOMS?
COVID-19’s incubation period, the time between exposure to the virus and symptoms appearing, ranges from 1 to 14 days, but most people will develop symptoms within 5 to 6 days of exposure. Australia’s national COVID-19 public health guidelines use a 14-day incubation period to guide advice on public health measures, such as quarantine and isolation.
It has been estimated that around 17% of infections are asymptomatic.
COVID-19 can range from an asymptomatic or mild illness to pneumonia, with symptoms that can include:
- fever, fatigue
- respiratory symptoms, including coughing, sore throat, shortness of breath, chest pain, runny or blocked nose
- muscle and/or joint pains
- nausea, diarrhoea, vomiting
- loss or altered sense of smell &/or taste
- loss of appetite
WHERE IS IT FOUND?
COVID-19 virus is currently a risk world-wide, however some Pacific islands have reportedly remained virus-free.
REDUCING THE RISK OF TRANSMISSION
When you are well
- If available, have your COVID-19 vaccinations.
- Physical distancing 1.5 metres away from others wherever possible and follow local public health guidelines which may include wearing masks, registering at venues and other protocols.
- Wash your hands often with soap and water or use alcohol-based hand sanitisers.
- Avoid touching your eyes, nose and mouth.
- Clean and disinfect surfaces you use often such as bench tops, desks and doorknobs
When you are sick
It is important that you stay at home if you feel unwell and continue to use good hygiene practice. If you have cold or flu-like symptoms, even if they are mild, you should get tested for COVID-19 and isolate until you have a negative test result (or as directed by the public health unit).
HOW IS COVID-19 TREATED?
Most people with COVID-19 disease will experience a mild to moderate respiratory illness and recover without requiring any specialist treatment. Rest, fluids and analgesia are generally the mainstays of treatment, however new therapies are being developed and the management of the disease remains under review. In cases of severe COVID-19 and for people at risk of complications, hospitalisation with supportive and antiviral treatment may be required.
WHAT IS COVID-19 VACCINATION?
The Australian Government’s COVID-19 free vaccination program for citizens, residents and most visa holders began in February 2021. The vaccines being used in Australia are effective and aimed at stopping the spread of the disease and reducing COVID-19 virus-related harm, preventing serious illness and loss of life, as much as possible. They are inactivated vaccines (not live) which are based on a harmless, non-replicating part of the virus to provoke an immune response in our bodies which will be remembered if we are ever exposed to the virus in the future.
The Australian Technical Advisory Group on Immunisation (ATAGI) currently recommends that the two available COVID-19 vaccines – AstraZeneca and Pfizer - are administered to people over the age 18 years. Studies have been carried out, and are continuing, into the suitability of giving the vaccines to children. The TGA is reported to be considering a Pfizer proposal to approve its Comirnaty vaccine for adolescents aged from 12 to 15 years in Australia; the vaccine is already being used in this age group in the UK and US. Read more
COVID-19 Vaccine AstraZeneca is now to be used for adults over the age of 50 years and (Pfizer/BioNTech) Comirnaty vaccine is preferred for adults aged 18- 50 years.
COVID-19 Vaccine AstraZeneca has a 2-dose vaccination schedule – minimum 4 weeks apart, but the recommendation in Australia is for the second dose to be given 12 weeks after the first dose.
Comirnaty is a 2-dose vaccination schedule given 21 days apart.
LEVEL OF PROTECTION
Both Comirnaty and COVID-19 Vaccine AstraZeneca currently require a 2-dose course for the best immune response. Whilst partial protection against COVID-19 may be provided as soon as 12 days after the first dose, this protection is likely to be short-lived. The second dose encourages the body to create stronger and longer-lasting protection (immunity) against SARS-CoV-2, the virus that causes COVID-19.
Individuals are not considered to be fully protected until 14 days after their second dose of the COVID-19 vaccines.
Studies continue into the duration of protection offered by the vaccines and the likely impact emerging virus variants may have on this.
PREGNANCY & BREASTFEEDING
On June 9, 2021, ATAGI and the Royal Australian and New Zealand College of Obstetricians and Gynaecologists (RANZCOG) issued a joint statement in which they recommended that 'pregnant women are routinely offered Pfizer mRNA vaccine (Cominarty) at any stage of pregnancy. This is because the risk of severe outcomes from COVID-19 is significantly higher for pregnant women and their unborn baby'.
While the timing of the vaccination during pregnancy should be discussed with your health professional, the joint statement advises that 'Global surveillance data from large numbers of pregnant women have not identified any significant safety concerns with mRNA COVID-19 vaccines given at any stage of pregnancy. There is also evidence of antibody in cord blood and breastmilk, which may offer protection to infants through passive immunity'.
There is also positive news for women who are planning pregnancy or who have recently become pregnant that they ‘do not need to delay vaccination or avoid becoming pregnant after vaccination’.
POSSIBLE SIDE EFFECTS
As with any vaccine, some temporary side effects may occur after receiving a COVID-19 vaccine.
Following COVID-19 Vaccine AstraZeneca, side effects may include:
- injection site pain or tenderness
- muscle pain
- fever and chills
Most side effects are mild and temporary, going away within 1-2 days. As with any medicine or vaccine, there may be rare and/or unknown side effects.
COVID-19 Vaccine AstraZeneca rare side effect - TTS
COVID-19 Vaccine AstraZeneca has been associated with a rare side effect (4-6 cases per million doses) called Thrombosis with thrombocytopenia syndrome (TTS), also known as Vaccine-induced prothrombotic immune thrombocytopenia (VIPIT), which appears to be more frequently reported following the first dose. This thrombotic syndrome differs from common venous thrombo-embolic disease in that it is immune- mediated, rather than associated with the commonly known risk factors for thrombosis. It tends to occur in unusual sites resulting in cerebral venous sinus thrombosis and splanchnic vein thrombosis, both of which carry significant morbidity and mortality. TTS following COVID-19 Vaccine AstraZeneca vaccination has occurred mostly in younger vaccine recipients (under 60 years of age).
Advice from the Australian Technical Advisory Group on Immunisation (ATAGI) on TTS in COVID-19 Vaccine AstraZeneca recipients is that these clotting complications have occurred between day 4 and 26 after vaccination. The Group states that ‘Consumers should be particularly alert to severe, persistent headaches that are different to their "usual" pattern and do not settle with paracetamol or other painkillers. If these symptoms occur consumers should seek medical advice as soon as possible. Anyone attending their GP or a hospital with any concerns should let their treating clinician know the details of the vaccine they received.’ Read more
Potential side effects after vaccination with Comirnaty:
Mostly mild to moderate & short-lasting.
- Very common side effects - may affect more than 1 in 10 people: Injection site pain & swelling, tiredness, headache, muscle pain, joint pain, chills, fever.
- Uncommon side effects - may affect up to 1 in 100 people: Enlarged lymph nodes, feeling unwell, pain in limb, insomnia, injection site itching.
- Rare side effects - may affect up to 1 in 1,000 people: temporary one sided facial drooping
Very rare side effects - in US seen in approximately 11 cases per 1 million vaccine doses: Anaphylaxis
AstraZeneca – Studies have shown approximately 62% effectiveness for 2 standard doses across age groups 18 years of age and above. (This may vary (62-90%) based on age, dose and time between doses)
Comirnaty - Studies determined 95% vaccine efficacy across all age groups from 16 years of age up to 75 years and older.
The length of protection offered by the 2 initial doses is still being studied in clinical trials.
CO-ADMINISTRATION WITH OTHER VACCINES:
The Australian Technical Advisory Group on Immunisation (ATAGI) has advised that any vaccines, including influenza, should be given at least 7 days before or after the Pfizer/BioNTech or COVID-19 Vaccine AstraZeneca vaccines, based on the current lack of data relating to any safety issues or interference with immune responses when given together. There are some occasions where on clinical advice the interval can be shortened or even allow for co-administration. (ATAGI 2021)
Further information can be found at:
- Australian Government Department of Health, COVID-19 vaccines – Is it true? https://www.health.gov.au/initiatives-and-programs/covid-19-vaccines/is-it-true
- NCIRS, COVID-19 Vaccines, Frequently asked questions: https://www.ncirs.org.au/covid-19/covid-19-vaccines-frequently-asked-questions
- Therapeutic Goods Administration, COVID-19 vaccines: https://www.tga.gov.au/covid-19-vaccines
Australian Government Department of Health: https://www.health.gov.au/initiatives-and-programs/covid-19-vaccines
RACGP: Australian study determines true asymptomatic COVID rate: https://www1.racgp.org.au/newsgp/clinical/australian-study-determines-true-asymptomatic-covi
Joint statement between RANZCOG and ATAGI about COVID-19 vaccination for pregnant women: https://www.health.gov.au/news/joint-statement-between-ranzcog-and-atagi-about-covid-19-vaccination-for-pregnant-women
Melbourne Vaccine Education Centre, Thrombosis with thrombocytopenia syndrome: https://mvec.mcri.edu.au/references/thrombosis-with-thrombocytopenia-syndrome/
World Health Organisation: https://www.who.int/health-topics/coronavirus#tab=tab_1