Covid-19 Vaccine Analysis: The most common adverse events reported so far


As of July 19, 2021 there were 419,513 adverse event reports associated with Covid-19 vaccination in the U.S., with a total of 1,814,326 symptoms reported. That’s according to the federal Vaccine Adverse Event Reporting System (VAERS) database.

Report an adverse event after vaccination online here.

Each symptom reported does not necessarily equal one patient. Adverse event reports often include multiple symptoms for a single patient.

Reporting of illnesses and symptoms that occur after Covid-19 vaccination does not necessarily mean they were caused by the vaccine. The system is designed to collect adverse events that occur after vaccination to uncover any patterns of illnesses that were not captured during vaccine studies.

Read CDC info on Covid-19 vaccine here.

Scientists have estimated that adverse events occur at a rate many fold higher than what is reported in VAERS, since it is assumed that most adverse events are not reported through the tracking system. Reports can be made by doctors, patients or family members and/or acquaintances, or vaccine industry representatives. 

Read: Exclusive summary: Covid-19 vaccine concerns.

Some observers claim Covid-19 vaccine adverse events are not as likely to be underreported as those associated with other medicine, due to close monitoring and widespread publicity surrounding Covid-19 vaccination.

Approximately 340 million doses of Covid-19 vaccine have been given in the U.S. Slightly less than half of the U.S. population is fully vaccinated.

According to the Centers for Disease Control (CDC) and Food and Drug Administration (FDA), the benefits of Covid-19 vaccine outweigh the risks for all groups and age categories authorized to receive it.

Watch: CDC disinformation re: studies on Covid-19 vaccine effectiveness in people who have had Covid-19.

The following is a summary of some of the most frequent adverse events reported to VAERS after Covid-19 vaccination. (It is not the entire list.)

Most common Covid-19 vaccine adverse events reported as of July 19, 2021

Yellow highlighted adverse events are subjects of investigations, warnings or stated concerns by public health officials. For details, click here.

128,370 Muscle, bone, joint pain and swelling including:

  • 39,902 Pain in extremity
  • 37,819 Myalgia, muscle pain, weakness, fatigue, spasms, disorders, related
  • 30,138 Arthralgia, joint pain or arthritis, swelling, joint disease, bone pain, spinal osteoarthritis
  • 14,682 Back pain, neck pain
  • 5,829 Muscle and skeletal pain, stiffness, weakness

119,866 Injection site pain, bleeding, hardening, bruising, etc.

105,332 Skin reddening, at injection site or elsewhere, rash, hives

100,564 Fatigue, lethargy, malaise, asthenia, abnormal weakness, loss of energy

89,302 Headache, incl. migraine, sinus

68,252 Vomiting, nausea

68,064 Fever

63,133 Chills

60,913 Pain

49,574 Dizziness

34,076 Flushing, hot flush, feeling hot, abnormally warm skin

31,785 Lung pain or abnormalities, fluid in lung, respiratory tract or lung congestion or infection, wheezing, acute respiratory failure including:

  • 23,005 Dyspnoea, difficulty breathing
  • 1,398 Pneumonia
  • 1,128 Respiratory arrest, failure, stopped or inefficient breathing, abnormal breathing
  • 563 Covid-19 pneumonia
  • 265 Mechanical ventilation
  • 217 Bronchitis

30,909 Skin swelling, pain, tightness, face swelling, swelling under skin, hives, angioedema including:

  • 7,579 Skin pain, sensitivity, burning, discoloration, tenderness

25,319 Heart failure, heart rhythm and rate abnormalities, atrial fibrillation, palpitations, flutter, murmur, pacemaker added, fluid in heart, abnormal echocardiogram including:

  • 3,105 Heart attack or cardiac arrest, sudden loss of blood flow from failure to pump to heart effectively, cardiac failure, disorder

22,085 Itchiness

29,861 Sensory disturbance including:

  • 8,236 Tinnitus, hearing noise
  • 7,951 Abnormal vision, blindness
  • 6,349 Ageusia, loss of taste, altered taste, disorders
  • 2,249 Anosmia, loss of smell, parosmia (rotten smell)
  • 2,075 Hypersensitivity
  • 1,560 Sensitivity or reaction to light 
  • 890 Hearing loss, deafness

Prevalence of anosmia and ageusia symptoms among long-term effects of COVID-19.

Authors: Moraschini V1Reis D1Sacco R2Calasans-Maia MD3

COVID‐19 is an infectious disease caused by severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2) that currently presents the greatest, most challenging health concern worldwide. Since the first reports of the disease in December 2019, clinicians and scientists have endeavored to understand the main symptoms, risk factors, and prognosis of the disease (Wynants et al., 2020). Although a significant portion of the infected population remains asymptomatic, many COVID‐19‐infected individuals develop symptoms that vary from mild to severe (Stasi et al., 2020).

Some patients may experience long‐term effects of COVID‐19, which persist for two or more weeks after the onset of the disease (Tenforde et al., 2020). Loss of taste (ageusia) and smell (anosmia) are symptoms that have drawn substantial attention from researchers because of their high prevalence in the early stages of the disease (Eliezer et al., 2020; Gane et al., 2020). However, recent studies have observed persistent dysgeusia and anosmia following recovery from COVID‐19 infection (Andrews et al., 2020; Garrigues et al., 2020; Panda et al., 2020).

The aim of this study was to estimate the prevalence of dysgeusia and anosmia in studies that assessed the long‐term effects of COVID‐19. Four databases (PubMed/MEDLINE, EMBASE, Scopus, and Lilacs) were searched for articles without any restrictions regarding language, and the inclusion criteria were based on the PECO strategy (Morgan et al., 2018). This review included studies that analyzed the prevalence of persistent symptoms (>30 days) of anosmia and dysgeusia in patients who had COVID‐19. There were no language restrictions. Two independent review authors (V.M. and M.D.C.M.) conducted the search‐and‐screening process, commencing with the analysis of titles and abstracts. Next, full papers were selected for careful reading and matched with the eligibility criteria for subsequent data extraction. The search strategy is described in Table S1.

Regarding the quality of the analyzed studies and risk of bias, one study was classified as low quality (Andrews et al., 2020), two as satisfactory (Garrigues et al., 2020; Horvath et al., 2020), and five as of high quality (Carfì et al., 2020; Carvalho‐Schneider et al., 2020; Chopra et al., 2020; Galván‐Tejada et al., 2020; Panda et al., 2020). The analyses can be viewed in Table S2.

The two review authors (V.M. and M.D.C.M.) independently performed risk‐of‐bias and study quality analyses. The Newcastle–Ottawa Scale (Lo et al., 2014) was used in the analysis of non‐randomized studies. For data analysis, the effects reported in one simple arm were estimated by dividing the number of patients with each symptom by the total number of patients with COVID‐19 in the sample and then by multiplying by 100 to estimate the percentage. The prevalence with 95% confidence intervals (CIs) was presented using the software Comprehensive Meta‐Analysis (BioStat).

A total of eight observational studies were selected for this study. Six cohort studies (Andrews et al., 2020; Carfì et al., 2020; Carvalho‐Schneider et al., 2020; Chopra et al., 2020; Horvath et al., 2020; Panda et al., 2020), one cross‐sectional study (Garrigues et al., 2020), and one case–control study (Galván‐Tejada et al., 2020) were included in this study (Figure S1). The studies analyzed 1,483 patients (773 male and 710 female) with a mean age of 48.3 ± 11.2. All patients were diagnosed with COVID‐19 through reverse transcription polymerase chain reaction (RT‐PCR) and exhibited mild, moderate, or severe symptoms. The mean overall follow‐up time was 60.7 days. The main data for each study are shown in Table ​Table11.

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Age-dependent appearance of SARS-CoV-2 entry sites in mouse chemosensory systems reflects COVID-19 anosmia-ageusia symptoms

Authors: Julien Brechbühl,Ana Catarina Lopes,Dean Wood,Sofiane Bouteiller,Aurélie de Vallière,Chantal Verdumo, and Marie-Christine Broillet


COVID-19 pandemic has given rise to a collective scientific effort to study its viral causing agent SARS-CoV-2. Research is focusing in particular on its infection mechanisms and on the associated-disease symptoms. Interestingly, this environmental pathogen directly affects the human chemosensory systems leading to anosmia and ageusia. Evidence for the presence of the cellular entry sites of the virus, the ACE2/TMPRSS2 proteins, has been reported in non-chemosensory cells in the rodent’s nose and mouth, missing a direct correlation between the symptoms reported in patients and the observed direct viral infection in human sensory cells. Here, mapping the gene and protein expression of ACE2/TMPRSS2 in the mouse olfactory and gustatory cells, we precisely identify the virus target cells to be of basal and sensory origin and reveal the age-dependent appearance of viral entry-sites. Our results propose an alternative interpretation of the human viral-induced sensory symptoms and give investigative perspectives on animal models.


The Corona Virus Disease 2019 (COVID-19) has federated worldwide scientific efforts for understanding the viral epidemiological mechanisms of the coronavirus 2 (SARS-CoV-2) that causes this severe acute respiratory syndrome. In humans, the viral syndrome is characterized by an increased mortality rate in aged and/or comorbidity patients associated with the upper respiratory infection symptoms, such as severe respiratory distress13. In addition to its major impact, COVID-19 is associated by its direct alteration of human olfaction and gustation, in absence of substantial nasal inflammation or coryzal signs, resulting to anosmia and ageusia in up to 77% of the patients47. While these sensory symptoms are well established and intensely affect everyday behaviors8,9, the precise related mechanisms remain elusive10.

The target cells of the virus share a molecular signature: the concomitant cellular expression of the angiotensin-converting enzyme 2 (ACE2) and of its facilitating transmembrane serine protease 2 (TMPRSS2), which plays a crucial role for the interaction of viral spike proteins with the host cell1113. Paradoxically, these entry sites seem to be lacking in sensory cells1418, while a direct SARS-CoV-2 contamination has been observed both in humans and rodents19,20, requesting further investigations to explain the sensory-associated symptoms2124. Therefore, the characterization of the animal model is necessary prior to its use to understand the causality underling the viral-induced sensory symptoms.

The use of mice is indeed limited for epidemiological studies due to their absence of hands, which, with aerosols, are the foremost passages of interindividual viral transmission25, as well as their published lack of SARS-CoV-2 ACE2-spike protein affinity26,27. Nevertheless, the ease of production of genetically modified mice and their scientific availability, as well as their well-studied and specialized chemosensory systems2830, make them a valuable ally for the development of potential prophylactic and protective treatments related to these sensory symptoms.

Thus, we aimed here at characterizing the potential viral entry sites across mouse sensory systems. We found SARS-CoV-2 entry cells to be of different origins depending on the sensory systems. In summary, the virus could target cells involved in tissue regulation such as the supporting cells of the olfactory receptor neurons and the regenerative basal cells but also, specifically, the chemosensory cells of both gustatory and olfactory systems. We finally revealed that the emergence of viral entry sites in sensory and basal cells only occurs with age, which could explain both, the observed COVID-19 long-lasting effects and the age-dependent sensory-symptomatology in human.

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COVID-19-Associated Bronchiectasis and Its Impact on Prognosis

Authors: Aasir M. SulimanBassel W. BitarAmer A. FarooqiAnam M. ElarabiMohamed R. AboukamarAhmed S. Abdulhadi


Coronavirus disease 2019 (COVID-19), which initially emerged in Wuhan, China, has rapidly swept around the world, causing grave morbidity and mortality. It manifests with several symptoms, on a spectrum from asymptomatic to severe illness and death. Many typical imaging features of this disease are described, such as bilateral multi-lobar ground-glass opacities (GGO) or consolidations with a predominantly peripheral distribution. COVID-19-associated bronchiectasis is an atypical finding, and it is not a commonly described sequel of the disease. Here, we present a previously healthy middle-aged man who developed progressive bronchiectasis evident on serial chest CT scans with superimposed bacterial infection following COVID-19 pneumonia. The patient’s complicated hospital course of superimposed bacterial infection in the setting of presumed bronchiectasis secondary to COVID-19 is alleged to have contributed to his prolonged hospital stay, with difficulty in weaning off mechanical ventilation. Clinicians should have high suspicion and awareness of such a debilitating complication, as further follow-up and management might be warranted.


Beginning in December 2019, a series of pneumonia cases were reported in Wuhan City, Hubei Province, China. Further investigations revealed that it was a new type of viral pneumonia caused by severe acute respiratory syndrome coronavirus 2 (SARS-Cov-2), which was termed coronavirus disease 2019 (COVID-19). Symptoms are variable, nonspecific, and include dry cough, fever, fatigue, myalgia, dyspnea, anosmia, and ageusia [1]. The real-time reverse transcription-polymerase chain reaction (rRT-PCR) test is the current gold standard for confirming infection and is performed using nasal or pharyngeal swab specimens.

Computerized tomography of the thorax (CT thorax), as a routine imaging tool for pneumonia diagnosis, is of great importance in the early detection and treatment of patients affected by COVID-19. Chest CT may detect the early parenchymal abnormalities in the absence of positive rRT-PCR at initial presentation [2]. Since chest CT was introduced as a diagnostic tool for COVID-19 pneumonia, many typical features of this disease were described such as bilateral multi-lobar ground-glass opacification (GGO) with a prevalent peripheral or posterior distribution, mainly in the lower lobes; sometimes, consolidative opacities superimposed on GGOs could be found [3]. To our knowledge, bronchiectasis is not a classical finding in COVID-19 pneumonia, with a paucity of reporting on its development and progression during the disease course.

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