COVID-19

What is COVID-19

Coronavirus disease 2019 (COVID) is caused by the severe acute respiratory distress syndrome coronavirus 2 (SARS-CoV-2). SARS-CoV-2 is a novel virus that emerged in Wuhan China in late 2019 and resulted in a global pandemic. Although it mainly affects the lungs, it can be a multi-system disease affecting the heart, gastrointestinal tract, nervous system and skin. 

cough covid-19

What are the symptoms of COVID-19?

People infected with SARS-CoV-2 may be asymptomatic, have mild symptoms or have severe disease requiring hospitalisation. 

The main symptoms of COVID-19 are:

  • Fever – high temperature
  • A new continuous cough – coughing for more than an hour or 3 or more coughing episodes in 24 h
  • Loss or change in sense of smell or taste

With novel variants such as Omicron the main symptoms may not be present.

Other symptoms include:

Who is more likely to get severe disease?

Fortunately most people who get infected with SARS-CoV-2 have mild symptoms. One in three may be asymptomatic. 

However, some people are at risk of severe disease requiring admission to hospital and possibly intensive care. Risk factors for severe disease include:

  • Older age
  • Male gender
  • Obesity
  • Diabetes
  • Hypertension
  • Chronic heart disease
  • Chronic lung disease
  • Cancer
  • Organ transplant
  • Smoking

How is COVID-19 treated?

For mild cases no specific treatment is needed. Self-isolation for 10 days is important to stop the the spread of the virus. Resting well and good hydration are very important. However, medication such as paracetamal and non-steroidal anti-inflammatory drugs (e.g. Ibuprofen) can be taken for fever and pain. Importantly, there is no cure for COVID-19 but for infected people treated at home, the use of inhaled budesonide (a corticosteroid) within 7 days of the onset of illness has been shown in the STOIC study to reduce the duration of illness. There is no strong evidence to support treatment with medication such as hydroxychloroquine, azithromycin, colchicine or ivermectin. 

Although most people recover well from COVID-19 some individuals will experience deterioration in symptoms, usually between day 7-12 of the illness,  sometimes even after initial improvement. If experiencing shortness of breath, measurement of oxygen saturations with a home pulse oximeter is useful. If oxygen saturations are 92% or less immediate medical assessment is needed and you should call 999 or visit your local accident and emergency department. 

For individuals requiring hospitalisation several treatments are available to reduce the duration of illness and risk of death. These include:

  • Remdesivir – Shortens the time to recovery by a median of 5 days 
  • Dexamethasone – Reduces 28-day mortality in those receiving oxygen (23% vs 26%) or requiring invasive mechanical ventilation (29% vs 41%) compared to those not on dexamethasone
  • Tocilizumab (anti-IL6) – Reduces mortality in critically ill adults
  • Ronapreve (casirivimab and imdevimab) – Approved for the prevention and treatment of COVID-19, in the UK it is used in the treatment of COVID-19 patients who don’t detectable antibodies to SARS-CoV-2. 

How can I prevent getting infected with SARS-CoV-2?

There are things that can be done to reduce the risk of infection with SARS-CoV-2 and prevent COVID-19. 

Important general measures include:

  • Washing your hands with soap and water for at least 20 seconds.
  • Using alcohol-based sanitiser (at least 60% alcohol concentration)
  • Clean and disinfect frequently touched surfaces
  • If in closed spaces try to ensure that there is adequate ventilation
  • Avoid contact with people who are infected
  • Maintain social distancing – a distance of 2 m is recommended – government social distancing regulations 
It is important to take up COVID-19 vaccination to reduce the risk of severe disease. Vaccination with the mRNA and adenovirus vector vaccines have been shown to reduce the incidence of symptomatic disease and severe disease.
A booster dose is now recommended 3-6 months after the primary vaccine schedule for all adults. Immunocompromised people should receive a 3rd dose 8 weeks after the 2nd dose and a booster dose 6 months later. 

 

Is vaccination against COVID effective?

Yes, the vaccines are effective at reducing symptomatic COVID-19 and severe COVID-19. 

The efficacy of the mRNA vaccines from Pfizer-BioNTech and Moderna was reported from clinical trials as 95% and 94% after the 2nd dose, respectively. Efficacy of the adenovirus vector vaccine by Oxford-Astrazeneca was reported as 70% after the second dose. 

Emerging SARS-CoV-2 variants have the potential to escape the vaccine but to date evidence suggests that currently available vaccines offer some protection against new variants of the virus. Pfizer-BioNTech reported in April 2021 that their mRNA vaccine was 100% effective at preventing severe disease in a South African trial where the B.1.351 (South African variant) is prevalent. It isn’t yet known how effective the vaccine is at prevent mild to moderate symptomatic disease. The Oxford-Astrazeneca vaccine study data from South Africa suggest reduced efficacy at preventing mild to moderate symptomatic disease caused by the South African variant.

Are COVID vaccines safe?

Yes, the vaccines approved by Medicines and Healthcare products Regulatory Agency (MHRA) are  considered safe. 

Both mRNA and adenovirus vector COVID vaccines are non-live vaccines and unable to replicate or cause infection. Essentially, the vaccines carry genetic code that the body will use to make a protein – the coronavirus spike protein. Once the immune system is exposed to the protein it will develop an immune response that can be used in the future to fight the virus if it encounters it in the future. 

The COVID vaccines have been tested in large clinical trials of approximately 23000, 30000 and 44000 participants involving the Oxford-Astrazeneca vaccine, Moderna and Pfizer-BioNTech, respectively. Many countries have had successful rollout of their vaccination programmes and millions of people have been vaccinated. This allowed monitoring of data by regulatory agencies to continue to establish the vaccines safety. 

Common side-effects of COVID vaccines include:

  • Arm pain
  • Fever
  • Chills
  • Muscle ache
  • Fatigue
  • Joint pain 
  • Headache
More recently the Oxford-Astrazeneca vaccine was associated with a rare clotting disorder and received a lot of media attention. In fact, all COVID vaccines have been associated with the development of cerebral venous thrombosis (CVT) and portal vein thrombosis (vein in the liver). Research from the University of Oxford has reported that CVT occurred in 39 in a million people receiving COVID vaccinations. Importantly, COVID-19 itself is associated with a greater risk of CVT than vaccinations – approximately 8-10 times higher risk of developing CVT from COVID0-19 than from vaccination.   

Are COVID vaccines safe in pregnancy and during breastfeeding?

Data regarding the safety of COVID vaccines during pregnancy and breastfeeding were lacking since pregnant and breastfeeding woman were excluded during the clinical trials. However, these trials are now being carried out. Theoretically, as these vaccines are non-live vaccines they should be safe as other non-live vaccines are administered to pregnant and breast feeding woman. The initial recommendation from the Joint Commitee on Vaccination and Immunisation (JCVI) in the UK was that if a woman was at high risk of exposure to SARS-CoV-2 (e.g. through workplace exposure) then the COVID vaccine was recommended after discussion with a healthcare professional. However, in April 2021 the recommendation has changed and all pregnant woman are now advised to have the vaccine at the same time that it is offered to other members of the population based on the priority groups. Importantly, JCVI have recommended that pregnant woman receive the Pfizer-BioNTech or Moderna mRNA vaccine irrespective of age as there is now more experience of these vaccines being used in pregnancy compared to with the Astrazenca vaccine. The recommendation for breastfeeding woman is that any of the vaccines can be used. 

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