Coronavirus disease 2019 (COVID) is caused by the severe acute respiratory distress syndrome coronavirus 2 (SARS-CoV-2). SARS-CoV-2 was a novel virus that emerged in Wuhan China in late 2019 and resulted in a global pandemic. Different variants have evolved since the first virus was identified and a high number of new infections continue to occur.
Although it mainly affects the upper and lower respiratory tract, it can be a multi-system disease affecting the heart, gastrointestinal tract, nervous system and skin.
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:
With novel variants such as Omicron the main symptoms may not be present and the condition mistaken for a common cold or other illness.
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:
For mild cases no specific treatment is needed. Self-isolation should be considered as it is important to stop the the spread of the virus. Resting well and good hydration are very important. For most 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 Coronavirus disease 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.
Several treatments are available to reduce the duration of illness and risk of death. These include:
For detail on the high risk groups eligible for neutralising monoclonal antibodies to prevent severe disease please see information from the Department of Health and Social Care.
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:
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.
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:
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.
Respiratory Medicine
Royal Brompton Hospital
Sydney Street
Chelsea
SW3 6NP
