11. COVID Flashcards
Coronaviruses
- Coronaviruses = group of viruses
- Impact: mild respiratory infections such as the common cold
- Rare forms include severe acute respiratory syndrome (SARS), middle
COVID 19
- SARS-CoV-2 member of the coronaviruses
- Incubation period: up to 2 weeks
- Spread: close contact and respiratory droplets
- Among the symptomatic, 5% become critically ill: respiratory failure, acute respiratory distress syndrome, sepsis; thromboembolism/multiorgan failure
Key dates
Late Jan-first case March-10,000+, Lockdown 1 April-100,000+ October-1M+ December-Lockdown 2, Pfizer vaccine approved January-Lockdown 3
Social distancing/masks
+Practical method to reduce reproductive value (RO) of virus since it can spread via airborne respiratory secretions from mouth and nose
-Common good conflicts suppression of personal liberty
Reproductive value
The average number of people an infected individual can pass the virus onto [contagion]
WHO: 2-2.5 in March 2020
Herd immunity
‘The resistance to the spread of a contagious disease within a population that results if a sufficiently high proportion of individuals are immune to the disease, primarily through vaccination [also mass infection]’
60-70%
+Avoid overwhelming our finite healthcare facilities as in Italy
+More proactive than social distancing because, more people will be generating immunity, effective post-lockdown
+Protects vulnerable groups
-Unclear if infection and recovery guarantees full immunity, and if so, for how long
-Initially, only way to develop immunity was mass infection; gambling lives of young and healthy on a 0.3-0.6% infection-fatality rate
Lockdown
+PHO believe necessary and effective for reducing transmission and saving lives
- Economic downturn: UK GDP 25% lower in April 2020; 500k businesses reported to be in severe economic hardship in September 2020
- Mental health
- Violation of individual rights and freedom
(1) Transparency: justification for lockdown clearly communicated
(2) Reciprocity: quarantines must be provided with food, shelter, support, non-discrimination
(3) Least restrictive: least restrictive setting to achieve goal of quarantine –> Tier –> restrictions on freedom proportionate to pandemic
Ventilators
- SARS-COV-2 is principally a respiratory pathogen; takes over breathing for a patient, giving their body time to fight off the virus
- 4,000 ventilators, acted to secure 30,000 by September 2020
- 6.6 critical care beds per 100,000 people vs average 11 in Europe
More beds and hospitals
(1) Nightingale Hospitals built –> 2 wards and a capacity for 4000 patient s
(2) Non urgent operations cancelled
(3) Increased discharge of patients where safe and practicable
Cancer patients (NHS England Cancer Resilience Plan)
- London needs to treat 500+ cancer patients/week but most green sites compromised
- Only 122 cancer cases treated in London as of recently
- 3840 priority 2 cancer patients waiting beyond target of 62 days for first treatment –> 4 weeks or risk to life or limb
Vaccine Clinical Trials
-Pre-clinical studies
-Phase 1: major safety concerns
-Phase 2 (100s): generates immune response consistently
-Phase 3 (1000s): safety and efficacy
Phase 4: post marketing surveillance by pharmas or regulatory bodies (MHRA, yellow card scheme)
Regulatory Bodies
- ICH-GCP
- Declaration of Helsinki
- EU Clinical Trials Directive
- RCPCH Guidelines
- NHS Research Ethics Committee
COVID expediated by
- Accumulated knowledge and technology from research on coronaviruses over the last 50 years
- Funding and resources; £850M invested in Europe, 3/4 COVID research published with open access; collaboration of datasets
- Regulatory bodies prioritising COVID research
Types of vaccines
- Pathogen
- Subunit
- Nucleic
Vaccine successes
- Polio eradicated in 1980s
- Smallpox eradicated; mortality rate of 30%
- Measles and diptheria reduced by 99.9%
- HPV vaccine caused 90% fall in pre-cancerous cells in vaccinated young women
