COVID-19 VIRUS

Scientific studies (review articles) on COVID-19 virus:

2022:

1. Myocarditis incidence after RNA vaccines is 0.0035%
2. COVID-19 vaccination reduces susceptibility to infection and transmission to others
3. COVID-19 mRNA vaccines are effective against symptomatic COVID-19 infection among immunocompromised patients
4. Overall effectiveness of Moderna vaccine against COVID-19 caused by delta variant is 91% after 2 doses

2020-2021:

1. Face mask use reduces COVID-19 infection
2. COVID-19 vaccination is recommended for IBD patients
3. COVID-19 first infections and reinfections have a similar clinical spectrum and management regimen
4. One-fifth of COVID-19 infections are asymptomatic throughout the course of infection
5. Vaccination effectively reduces new cases and deaths of COVID-19
6. COVID-19 vaccines effectively reduce death, severe cases, symptomatic cases and infections across the world
7. Lactoferrin supplementation reduces respiratory illness
8. Antigen test is an effective tool to prevent COVID-19 transmission
9. Vitamin C supplementation does not reduce risk of COVID-19
10. Efficacy for mRNA COVID-19 vaccines is 85% in people over 18 years
11. Vitamin D supplements should be added to treatment protocols of COVID-19 disease
12. No gender differences in the efficacy of COVID-19 vaccines
13. Cloth face masks should not be used in places where social distancing is impossible
14. Anticoagulant therapy decreases mortality in hospitalized patients with COVID-19
15. The asymptomatic rate of COVID-19 is around 35%
16. COVID-19 adults have a much higher level of symptomatic severity, fever and CT-positive than COVID-19 children
17. Dyslipidemia increases severity and mortality of COVID-19
18. Prolonged international normalized ratio values are associated with COVID-19 severity and mortality
19. Low serum vitamin D levels increase COVID-19 infection
20. 1-2 m physical distancing, face mask and eye protection reduce risk of COVID 19 infection
21. CK-MB concentrations increase severity and mortality in COVID-19 patients
22. Overall vaccine effectiveness of Pfizer-BioNTech COVID 19 mRNA vaccine is 95%
23. COPD is associated with negative COVID-19 related health outcomes
24. Tocilizumab reduces 28-day all-cause mortality among hospitalized COVID-19 patients
25. mRNA vaccines are the most effective against COVID-19
26. Zinc supplementation has no beneficial impact on the course of COVID-19
27. Intravenous immunoglobulin therapy could reduce mortality of critical ill patients with COVID-19
28. Vitamin D deficiency is associated with greater severity of COVID-19 infection
29. Hospitalization rate of COVID-19 is higher among MS patients
30. IL-6 inhibitor agents reduce mortality in severe COVID-19
31. Cardiovascular drugs may not be associated with poor COVID-19 outcomes
32. Adenovirus-vectored and mRNA-based COVID-19 vaccines show highest efficacy after first and second doses
33. IFN-α cannot be used as a severity marker for COVID-19
34. Smoking is associated with an increased risk for death in patients with COVID-19
35. Most prevalent neurological comorbidity in COVID-19 is cerebrovascular disease
36. Low-dose aspirin use may reduce mortality in patients with COVID-19
37. Severe COVID-19 infection is associated with higher D-dimer values, lower platelet count and prolonged prothrombin time
38. Malignancy increases severe/critical COVID-19
39. Tocilizumab reduces 28-30 days all-cause mortality and intensive care unit admission among hospitalized COVID-19 patients
40. Anakinra may reduce need for invasive mechanical ventilation and mortality of hospitalized non-intubated patients with COVID-19
41. AstraZeneca COVID-19 vaccine produces highest T cell ELISpot responses
42. Global basic reproduction number of COVID-19 is 4
43. High-dose methylprednisolone probably decreases mortality from COVID-19
44. Parkinson's disease increases severity and mortality from COVID-19
45. Physical activity enhances immune system and increases potency of vaccination
46. Timing of intubation has no effect on mortality and morbidity of critically ill patients with COVID-19
47. Overall quality of studies about COVID-19 disease is remarkably low
48. Routine use of colchicine reduces COVID-19 severity and mortality
49. Immunosuppression therapy does not increase risk of COVID-19
50. Convalescent plasma treatment reduces mortality rate among COVID-19 patients
51. Convalescent plasma does not decrease all-cause mortality in COVID-19 patients
52. Famotidine does not reduce serious illness, death and intubation for COVID-19 patients
53. Rheumatic disease is a risk factor for poor outcomes in patients with COVID-19
54. Dementia increases mortality from COVID-19 infection
55. Meteorological conditions are not associated with COVID-19 transmission
56. Vitamin D deficiency increases severity of COVID-19
57. COVID-19 pandemic increases anxiety among women during pregnancy and perinatal period
58. 74.8% of COVID-19 patients have sleep problems
59. Hospital discharged rate of COVID-19 is lower than influenza
60. Clinical and radiological improvement with favipiravir in COVID-19 patients
61. COVID-19 increases risk of mortality in patients with hip fracture
62. Blood group O decreases risk of COVID-19
63. Coronavirus infection is more likely to affect pregnant women
64. Systemic steroid therapy may not be effective for reducing mortality, duration of hospitalization and period of viral shedding among COVID-19 patients
65. Quarantined households will be a significant venue for transmission of COVID-19
66. Infection risk of COVID-19 of household contacts is 10 times higher than other contacts
67. Severe COVID-19 patients have lower haemoglobin level and red blood cell count and higher ferritin level and red cell distribution
68. Pooled mortality rate among COVID-19 patients is 6.6%
69. Mortality is 12% lower for COVID-19 patients treated with tocilizumab
70. DPP-4 inhibitor use is associated with lower mortality in COVID-19 patients
71. Use of ACEI/ARB is not associated with increased mortality or severe COVID-19
72. ACEI/ARB therapy should be continued in COVID-19 patients
73. Proportion of health care workers who are SARS-CoV-2 positive among all COVID-19 patients is 10.1%
74. COVID-19 is highly detected in lower respiratory tract specimens
75. Patients with COVID-19 present neurological and musculoskeletal symptoms
76. Severe rate is more than 40% in COVID-19 patients with gastrointestinal symptoms
77. Gastrointestinal symptoms with COVID-19 are associated with a higher risk of acute respiratory distress syndrome
78. Convalescent plasma therapy is a potentially effective treatment for COVID-19
79. Anakinra might be associated with reductions in both mortality and need for mechanical ventilation in COVID-19 patients
80. Some patients with COVID-19 have multiple organ dysfunction
81. Mortality rate of patients admitted to intensive care unit with COVID-19 is around 41%
82. Rate of Intensive Care Unit admission of COVID-19 is 32%
83. Umifenovir does not improve patient-important outcomes in patients with COVID-19
84. Anti-cancer therapy have no adverse effects on severity and mortality in cancer patients with COVID-19
85. Cancer has a significant impact on mortality rate in COVID-19 patients
86. Cancer comorbidity is associated with the risk and severe events of COVID-19
87. Lung cancer and colorectal cancer are more susceptible to COVID-19 infection
88. A high neutrophil-to-lymphocyte ratio level is associated with severe COVID-19 and mortality
89. Low leukocyte and neutrophil counts are markers of COVID-19 infection
90. Chest radiographical imaging could be conducive to early identification of asymptomatic COVID-19 infections
91. 55.5% female and 49.6% children are asymptomatic COVID-19 cases
92. 15.6% of confirmed COVID-19 patients are asymptomatic
93. Asymptomatic patients are a potential source of transmission of COVID-19
94. Routine use of systemic glucocorticoids for patients with COVID-19 cannot be recommended
95. 43.7% COVID-19 patients carry SARS-CoV-2 in their intestinal tract
96. COVID-19 children are potential carriers, like adults and can transmit the infection among the population
97. Fever, respiratory symptoms and gastrointestinal manifestations are most common among children with COVID-19
98. Nearly half of COVID-19 infection in children under 5 years are asymptomatic
99. Children account for a small proportion of COVID-19 in household transmission cluster
100. Critical cases of COVID-19 among children under 1-year account for 14%
101. Infants and neonates are more vulnerable to more severe COVID-19 disease than older children
102. Multisystem inflammatory syndrome in children leads to multiple organ failure
103. Leukopenia is associated with a better prognosis of COVID-19
104. Mild‐to‐moderate fever and cough are most common symptoms among children with COVID‐19
105. Physical distancing interventions in 149 countries are associated with a 13% reduction in the incidence of covid-19 globally
106. Physical distancing of at least 1 m is strongly associated with COVID-19 protection
107. No routine use of antibiotics in the management of confirmed COVID-19 infection
108. Dyslipidemia is associated with severe COVID-19 infections
109. A low albumin level increases severe COVID-19 infection
110. Low-dose corticosteroid therapy appears to have a beneficial role in the management of severely ill COVID-19 patients
111. Dyspnoea is the only symptom predictive for severe COVID-19 and ICU admission
112. Pooled average incubation period of COVID-19 is about 6 days
113. Mean incubation period of COVID-19 ranges from 5.6 to 6.7 days
114. Median incubation period of COVID-19 is around 5 days
115. Basic reproduction number of COVID-19 infection is 3.15
116. Chest CT manifestations in children with COVID-19 could be used for early identification
117. Chest CT offers the great sensitivity for detecting COVID-19
118. Combination of hydroxychloroquine and azithromycin increase mortality in hospitalized COVID-19 patients
119. No benefit of hydroxychloroquine in patients affected by mild to moderate COVID-19 disease
120. Hydroxychloroquine may be associated with high adverse effects in COVID-19 patients
121. Hydroxychloroquine increases mortality among COVID-19 patients
122. Hydroxychloroquine increases mortality in patients with COVID-19
123. Severity of COVID-19 is associated with liver damage
124. Co-existing chronic liver disease presented up to 37.6% of patients with COVID-19
125. Liver injury is associated with severe COVID-19 infection
126. "Loss of smell" is a prevalent symptom in COVID-19 patients
127. One-seventh of patients with COVID-19 has olfactory and gustatory abnormalities as initial symptoms
128. Olfactory and gustatory dysfunction are common symptoms in patients with COVID-19
129. Dyspnea, hemoptysis, anorexia, diarrhea, fatigue and abdominal pain are associated with severe COVID-19
130. Severe COVID-19 patients have more neutrophils, higher neutrophil-to-lymphocyte ratio level and fewer lymphocytes
131. A high procalcitonin level increases severe COVID-19 infection
132. COVID-19 patients have elevated C-reactive protein, decreased lymphocyte count and increased lactate dehydrogenase
133. Lymphopenia is associated with severe COVID-19 infections
134. Pulmonary thromboembolism is a significant complication of COVID-19 who were admitted to ICU
135. Coagulation dysfunction is associated with severity of COVID-19
136. Lung lesions of patients with COVID-19 are bilateral lungs or multilobar
137. Tocilizumab reduces mechanical ventilation in severe COVID-19 patients
138. Tocilizumab may have potential effectiveness to treat COVID-19
139. Addition of tocilizumab to standard of care reduces mortality in severe COVID-19 patients
140. Tocilizumab reduces mortality risk in severe COVID-19 patients
141. Lopinavir-Ritonavir, Remdesivir and Tocilizumab may have some benefits in COV-2019 patients
142. Corticosteroids and remdesivir reduce mortality among hospitalized COVID-19 patients
143. COVID-19 patients benefit from remdesivir
144. Remdesivir for 10-day in hospitalized patients with COVID-19 is associated with lower 28-day all-cause mortality
145. COVID-19 patients given remdesivir are associated with higher rates of hospital discharge
146. Combination of ribavirin and corticosteroids may decrease mortality in COVID-19 patients
147. Conjunctivitis is more frequent in severe COVID-19
148. Elevated red blood cell distribution width levels are associated with adverse outcomes in COVID-19 patients
149. Lower serum prealbumin concentrations are associated with COVID-19 severity and mortality
150. Inflammatory markers are positively correlated with severe COVID-19
151. Elevated IL-6 level is associated with severe COVID-19
152. IL-6 values in the blood of healthy donors vary between 0 and 43.5 pg/mL
153. IL-6 and IL-10 as predictors of disease severity in COVID-19 patients
154. People under 40 years old represent around 6% of severe COVID-19 cases in Europe
155. Mortality rate of COVID-19 patients admitted to hospitals is 17.1%
156. Threshold of mortality of COVID-19 is >50 years
157. ≥65 years, male, hypertension, cardiovascular disease, diabetes, COPD and malignancies are associated with a greater risk of death from COVID-19 infection
158. Males and patients, aged ≥50 years are at higher risk of COVID-19 severity
159. Men had a 60% higher risk of COVID-19-related death than women
160. Male are more susceptible to severe COVID-19 infection than women
161. Male to female ratio of confirmed COVID-19 patients is 55 to 45
162. Male, aged over 65, smoking patients have a greater risk of COVID-19
163. 66.6% of COVID-19 deceased are male, with a median age of 69.9 years
164. 5 most common long-term effects of COVID-19 are fatigue, headache, attention disorder, hair loss and dyspnea
165. Fever is the most common symptom in patients with COVID-19
166. Symptoms of covid-19 infection are fever, cough, muscle aches and/or fatigue, dyspnea, headache, sore throat and gastrointestinal symptoms
167. COVID-19 infected patients and hospitalization is associated with a case fatality rate of >13%
168. Saliva and deep throat sputum swabs are promising diagnostic tools for first-line screening of COVID-19 infection
169. Antibody testing alone is unlikely to be an adequate solution to COVID-19 pandemic
170. 10% of patients with coronavirus infections might be missed with PCR tests
171. Serology tests play an important role in the clinical diagnosis for later stage COVID-19 patients
172. Nasopharyngeal swabs remain gold standard for diagnosis of COVID-19
173. Saliva NAAT diagnostic accuracy is similar to that of nasopharyngeal swab NAAT
174. ELISA tests have a specificity higher than 99% and sensitivity of 93% for COVID-19 infection
175. Severe COVID-19 shows higher levels of leukocyte, neutrophil, CRP, PCT, total bilirubin, urea and creatine
176. Heart injury is associated with severe outcome and death from COVID-19 infection
177. Troponin I >13.75 ng/L combined with >60 years is the best model to predict poor outcomes of COVID-19
178. Low platelet count is associated with an increased risk of severe disease and mortality in patients with COVID-19
179. Mass testing and contact tracing with social distancing and face coverings are most effective in bringing COVID-19 virus under control
180. Consistent use of masks covering mouth and nose plays an important role in containing the spread of COVID-19
181. Face mask reduces risk of COVID-19 infection with 62%
182. Face mask use reduces risk of COVID-19 infection
183. Face mask may reduce primary respiratory infection risk by 6-15%
184. Face mask with or without hand wash does not reduce influenza-like illness in community settings
185. Face masks protect against COVID-19 infection on healthcare workers and non-healthcare workers
186. N95 respirators compared with surgical masks is not associated with a lower risk of laboratory-confirmed influenza
187. Medical masks and N95 respirators offer similar protection coronavirus
188. Severe COVID-19 patients have a 4.74-fold increase in risk of myocardial injury
189. Pre-existing cardiovascular diseases is associated with worse outcomes among patients with COVID-19
190. There is a wide spectrum of cardiac involvement in COVID-19 patients
191. Cardiovascular metabolic diseases increase risk of corona virus infection
192. High NT-pro BNP and CK-MB levels in COVID-19 patients correlate with worse outcomes
193. COPD and smoking are associated with severe COVID-19 outcomes
194. COPD and current smokers are at greater risk of severe complications and higher mortality rate of COVID-19 infection
195. Excess adiposity is a risk factor for severe disease and mortality in people with COVID-19 infection
196. Obesity increases severe COVID-19
197. Abdominal adiposity is a risk factor in COVID-19
198. An increased BMI is associated with increased poor outcome in patients with COVID-19
199. Hypocalcemia is associated with poor outcome in COVID-19 patients
200. Elevated D-dimer levels increase risk of severe and mortality among patients with COVID-19 infection
201. Elevated D-dimer levels increase severity and mortality of COVID-19
202. D-dimer, fibrinogen, CRP, hs-CRP, ferritin and IL-6 are associated with increased severity and mortality in COVID-19 infection
203. In-hospital use of DPP4i reduces COVID-19 mortality among patients with diabetes mellitus
204. Patients with diabetes should be advised to continue taking metformin drugs despite COVID-19 infection status
205. Severe COVID-19 is associated with increased blood glucose levels
206. Diabetes increases in-hospital mortality in patients with COVID-19
207. Diabetes mellitus is associated with severe infection and mortality in patients with COVID-19
208. Diabetes in patients with COVID-19 is associated with a two-fold increase in mortality as well as severity of COVID-19
209. COVID-19 patients with chronic kidney disease have a high mortality risk
210. An increased risk of severity and mortality in COVID-19 patients with liver disease or chronic kidney disease
211. Acute kidney injury is associated with worse prognosis in COVID-19 patients
212. Acute kidney injury is associated with mortality, severity and the need for ICU care in COVID-19 patients
213. All persons with diabetes should receive influenza vaccination
214. Patients older than 60 years, with hypertension, diabetes and D-dimer values above 3.17 µg/mL have higher thrombotic events due to COVID-19
215. Statin use is associated with improved clinical outcomes in patients with COVID-19
216. Hypertension, diabetes, cardiovascular diseases, chronic obstructive pulmonary disease, chronic kidney disease and cancer are associated with poor prognosis in COVID-19 patients
217. Hypertension, diabetes, cardiovascular diseases and chronic kidney disease are risk factors for COVID-19 infection
218. Hypertension, cardiovascular diseases, diabetes mellitus, smoking, COPD, malignancy and chronic kidney disease are risk factors for COVID-19 infection
219. Patients with autoimmune diseases have an increased risk of COVID-19
220. Asthma is not associated with severe COVID-19, mortality and other poor outcomes in patients with COVID-19
221. Mortality is more frequently in COVID-19 patients with chronic kidney diseases and cardiovascular disease
222. COVID-19 patients from North American, European and Middle East countries suffer more severe liver, kidney and heart damage
223. Increase in clinical frailty scale is associated with increase in mortality among COVID-19 patients

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• In late 2019, a novel corona virus (first: 2019-nCov, then: SARS-CoV-2 or COVID-19) was identified as the cause of a cluster of pneumonia cases, which infected a lot of people in Wuhan, a city in the Hubei province of China.
• Coronavirus disease (COVID-19) is an infectious disease caused by a newly discovered coronavirus.
  COVID-19 is a new strain of coronavirus that has not been previously known in humans.
• The COVID-19 causing coronavirus is an enveloped RNA virus that utilizes an enzyme RNA dependent RNA polymerase for its replication.
• The SARS-CoV-2 or COVID-19 virus is studded with so-called spike proteins that it uses to enter human cells.
• Since COVID-19 is a newly identified pathogen, there is no pre-existing immunity to it in the human community, also there is no definitive cure to interrupt or reduce its astonishing spread.
• COVID-19 virus belongs to a relatively well-known viral family, Coronaviridae and is similar to viruses that caused severe acute respiratory syndrome (SARS), which had an outbreak in 2002 and Middle East respiratory syndrome (MERS), which had an outbreak in 2012.
• Everyone is susceptible to COVID-19 virus.
  Most people infected with the COVID-19 virus will experience mild to moderate respiratory illness and recover without requiring special treatment. 
  However, older people and those with underlying medical problems like cardiovascular disease, diabetes, chronic respiratory disease and cancer are more likely to develop serious illness.
• People can catch COVID-19 from others who have the virus. The disease can spread from person to person through small droplets from the nose or mouth which are spread when a person with COVID-19 coughs or exhales. These droplets land on objects and surfaces around the person.
  Other people then catch COVID-19 by touching these objects or surfaces, then touching their eyes, mouth or nose. People can also catch COVID-19 if they breathe in droplets from a person with COVID-19 who coughs out or exhales droplets.
  This is why it is important to stay more than 1 meter (3 feet) away from a person who is sick.
• COVID-19 is transmitted from human to human. At this time, it is assumed that one sick person can infect 2 other persons on average; this is called the basic reproduction number. The sicker a person becomes, the more likely he/she is to spread the virus.
• The basic reproduction number, R nought (R0), is defined as the average number of secondary cases of an infectious disease arising from a typical case in a totally susceptible population, and can be estimated in populations if pre-existing immunity can be accounted for in the calculation.
• R0 determines the herd immunity threshold and therefore the immunisation coverage required to achieve elimination of an infectious disease.
  As R0 increases, higher immunisation coverage is required to achieve herd immunity.
• If R0 is less than 1, the disease will die out in a population, because on average an infectious person will transmit to fewer than one other susceptible person. On the other hand, if R0 is greater than 1, the disease will spread.
• Herd immunity (also called herd effect, community immunity, population immunity or social immunity) is a form of indirect protection from infectious disease that occurs when a large percentage of a population has become immune to an infection, whether through vaccination or previous infections, thereby providing a measure of protection for individuals who are not immune.
• According to experts roughly 60% of the population needs to be immune to COVID-19 to achieve herd immunity.
• The most common symptoms of COVID-19 are fever (>38 degrees Celsius), tiredness and dry cough. However, some patients may have aches and pains, nasal congestion, runny nose, sore throat or diarrhoea. These symptoms are usually mild and begin gradually. Some people become infected but don’t develop any symptoms and don't feel unwell.
• Most people (about 80%) recover from the disease without needing special treatment.
  Around 1 out of every 6 people who gets COVID-19 becomes seriously ill and develops difficulty breathing.
  People with fever, cough and difficulty breathing should seek medical attention.
• The “incubation period” means the time between catching the virus and beginning to have symptoms of the disease.
  The incubation period for COVID-19 virus range from 1-14 days, most commonly around 5 days.
• What you can do to prevent the spread of COVID-19:
  • Cough and sneeze on the inside of your elbow
  • Keep sufficient distance (1.5-2m) from each other
  • Limit social contacts
  • No handshaking
  • Stay at home as much as possible
  • Stay at home with symptoms of the common cold or flu
  • Use paper tissues and throw them away
  • Wash your hands with soap regularly 
• WHO has approved the following COVID-19 vaccines for use:
  • Pfizer-BioNTech (8 January 2021)
  • Oxford-AstraZeneca (25 January 2021) and
  • Janssen (17 March 2021)
• Traditionally, vaccines are made from a very weak form of bacteria or a dead version of a virus. Introducing a weak or dead version of a germ teaches your immune system how to fight it off.
• Adenovirus (or viral)-vectored (DNA) COVID-19 vaccine delivers the genetic instructions for SARS-CoV-2 (COVID-19) antigens directly into patients’ cells, provoking a robust immune response.
• Oxford-AstraZeneca COVID-19 vaccine (ChAdOx1 nCoV-19 or AZD1222 vaccine) is adenovirus-vectored COVID-19 vaccine. Oxford-AstraZeneca vaccine uses double-stranded DNA.
• The Oxford-AstraZeneca vaccine is based on the virus’s genetic instructions for building the spike protein. The spike protein is found on the surface of the virus that causes COVID-19. These instructions are stored in double-stranded DNA.
• In the Oxford-AstraZeneca vaccine the gene for the coronavirus spike protein has been added to another virus called an adenovirus.
  Adenoviruses are common viruses that typically cause colds or flu-like symptoms. The Oxford-AstraZeneca vaccine used a modified version of a chimpanzee adenovirus, known as ChAdOx1. It can enter cells, but it can’t replicate inside them.
• DNA is not as fragile as RNA and the adenovirus’s tough protein coat helps protect the genetic material inside. As a result, the Oxford-AstraZeneca vaccine doesn’t have to stay frozen.
• The recommended dosage of Oxford-AstraZeneca vaccine is 2 doses given intramuscularly (0.5ml each) with an interval of 8 to 12 weeks
• Unlike the Oxford-AstraZeneca COVID-19 vaccine, Russian Sputnik V COVID-19 vaccine and the Chinese CanSino Biologics COVID-19 vaccine use human adenovirus viral vectors.
• Janssen COVID-19 vaccine or Johnson & Johnson COVID-19 vaccine is a non-replicating, viral vector-based vaccine.
• Janssen COVID-19 vaccine requires only 1 dose.
• Adenovirus-vectored (DNA) COVID-19 vaccine does not alter your DNA in any way.
• mRNA COVID-19 vaccines deliver the RNA directly to human cells, encapsulated in tiny fat droplets to protect it.
  The mRNA vaccines must be stored at low temperatures to keep the RNA stable. This may make it harder to distribute and use these vaccines in some countries.
• Researchers have been studying and working with mRNA vaccines for decades. mRNA vaccines have been studied before for flu, Zika, rabies and cytomegalovirus (CMV). However, COVID-19 vaccines are the first mRNA vaccines.
• Pfizer-BioNTech and Moderna COVID-19 vaccine are mRNA (messenger RNA) vaccines and contain a molecule called messenger RNA (mRNA) with instructions for producing a protein known as the spike protein, which is naturally present in SARS-CoV-2, the virus that causes COVID-19.
  The vaccine works by preparing the body to defend itself against SARS-CoV-2.
• The Pfizer-BioNTech and Moderna vaccines require 2 doses, about a month apart. Each dose has a purpose. The first one introduces your immune system to the proteins COVID-19 is made of. This triggers an immune response and creates antibodies to fight the virus. But if your body only sees that protein once, the antibodies may disappear over time because your body doesn’t think that invader is a threat anymore.
• mRNA vaccines are made from a small, harmless piece of the virus’s genetic material.
• mRNA vaccines teach human cells how to make a protein or even just a piece of a protein, that triggers an immune response inside the human body.
• mRNA vaccines do not use the live virus that causes COVID-19.
• mRNA vaccines do not affect or interact with the DNA in any way.
• mRNA never enters the nucleus of the cell, which is where our DNA (genetic material) is kept.
• The human cell breaks down and gets rid of the mRNA soon after it is finished using the instructions.
• The benefit of mRNA vaccines is those vaccinated gain protection without ever having to risk the serious consequences of getting sick with COVID-19.
• A very rare side effect of Vaxzevria (formerly COVID-19 vaccine AstraZeneca) is unusual blood clots with low blood platelets.
  Most of the cases reported so far have occurred in women under the age of 60 years.
  Most cases occurred within 2 weeks of the person receiving their first dose.
• Patients should seek medical assistance immediately if they have the following symptoms after Vaxzevria vaccination:
  • shortness of breath
  • chest pain
  • swelling in your leg
  • persistent abdominal (belly) pain
  • neurological symptoms, including severe and persistent headaches or blurred vision
  • tiny blood spots under the skin beyond the site of injection