COVID-19 vaccine in the context of Irregular menstruation

The global COVID-19 pandemic (also known as the coronavirus pandemic), caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), began with an outbreak in Wuhan, China, in December 2019. Soon afterward, it spread to other parts of Asia and then worldwide in early 2020. The World Health Organization (WHO) declared the outbreak a public health emergency of international concern (PHEIC) on 30 January 2020, and assessed it as having become a pandemic on 11 March. The WHO declared the public health emergency caused by COVID-19 had ended in May 2023.

COVID-19 symptoms range from asymptomatic to deadly, but most commonly include fever, sore throat, nocturnal cough, and fatigue. Transmission of the virus is often through airborne particles. Mutations have produced many strains (variants) with varying degrees of infectivity and virulence. COVID-19 vaccines were developed rapidly and deployed to the general public beginning in December 2020, made available through government and international programmes such as COVAX, aiming to provide vaccine equity. Treatments include novel antiviral drugs and symptom control. Common mitigation measures during the public health emergency included travel restrictions, lockdowns, business restrictions and closures, workplace hazard controls, mask mandates, quarantines, testing systems, and contact tracing of the infected.

As of 12 August 2024, 13.53 billion COVID-19 vaccine doses have been administered worldwide, with 70.6 percent of the global population having received at least one dose. While 4.19 million vaccines were then being administered daily, only 22.3 percent of people in low-income countries had received at least a first vaccine by September 2022, according to official reports from national health agencies, which are collated by Our World in Data.

During a pandemic on the rapid timeline and scale of COVID-19 cases in 2020, international organizations like the World Health Organization (WHO) and Coalition for Epidemic Preparedness Innovations (CEPI), vaccine developers, governments, and industry evaluated the distribution of the eventual vaccine(s). Individual countries producing a vaccine may be persuaded to favor the highest bidder for manufacturing or provide first-class service to their own country. Experts emphasize that licensed vaccines should be available and affordable for people at the frontlines of healthcare and in most need.

COVID-19 Vaccines Global Access, abbreviated as COVAX, was a worldwide initiative aimed at equitable access to COVID-19 vaccines directed by the GAVI vaccine alliance, the Coalition for Epidemic Preparedness Innovations (CEPI), and the World Health Organization (WHO), alongside key delivery partner UNICEF. It was one of the four pillars of the Access to COVID-19 Tools Accelerator, an initiative begun in April 2020 by the WHO, the European Commission, and the government of France as a response to the COVID-19 pandemic. COVAX coordinated international resources to enable low-to-middle-income countries equitable access to COVID-19 tests, therapies, and vaccines. UNICEF was the key delivery partner, leveraging its experience as the largest single vaccine buyer in the world and working on the procurement of COVID-19 vaccine doses, as well as logistics, country readiness and in-country delivery.

By 19 October 2020, 184 countries had joined COVAX.

COVIran Barekat (Persian: کووایران برکت) is a COVID-19 vaccine developed in Iran by Shifa Pharmed Industrial Group, a subsidiary of the Barkat Pharmaceutical Group. It is an inactivated virus-based vaccine. Iranian authorities have authorized its emergency use. This makes it the first locally developed COVID-19 vaccine to be approved for emergency use in the Middle East.

Officials in charge say they are in the process to publish the results of the clinical trials in a peer-reviewed journal. The interim results of the phases 1 and 2 trials showed 93.5% (95% CI, 88.4–99.6%) of the receivers of the vaccine have produced neutralizing antibodies against SARS-CoV-2. Those results have not been peer-reviewed and describe the immunogenicity of the vaccine and not its efficacy. On 3 March 2022, peer-reviewed results have been published in the Clinical Microbiology and Infection.

On December 31, 2019, China announced the discovery of a cluster of pneumonia cases in Wuhan. The first American case of COVID-19 was reported on January 20, and Health and Human Services Secretary Alex Azar declared a public health emergency on January 31. Restrictions were placed on flights arriving from China, but the initial U.S. response to the COVID-19 pandemic was otherwise slow in terms of preparing the healthcare system, stopping other travel, and testing. The first known American deaths occurred in February and in late February President Donald Trump proposed allocating $2.5 billion to fight the outbreak. Instead, Congress approved $8.3 billion and Trump signed the Coronavirus Preparedness and Response Supplemental Appropriations Act, 2020 on March 6. Trump declared a national emergency on March 13. The government also purchased large quantities of medical equipment, invoking the Defense Production Act of 1950 to assist. By mid-April, disaster declarations were made by all states and territories as they all had increasing cases. A second wave of infections began in June, following relaxed restrictions in several states, leading to daily cases surpassing 60,000. By mid-October, a third surge of cases began; there were over 200,000 new daily cases during parts of December 2020 and January 2021.

COVID-19 vaccines became available in December 2020, under emergency use, beginning the national vaccination program, with the first vaccine officially approved by the Food and Drug Administration (FDA) on August 23, 2021. Studies have shown them to be highly protective against severe illness, hospitalization, and death. In comparison with fully vaccinated people, the CDC found that those who were unvaccinated were from 5 to nearly 30 times more likely to become either infected or hospitalized. There nonetheless was some vaccine hesitancy for various reasons, although side effects were rare. There were also numerous reports that unvaccinated COVID-19 patients strained the capacity of hospitals throughout the country, forcing many to turn away patients with life-threatening diseases.

Right-wing antiglobalism, also referred to as the antiglobalist right, is a political position opposing globalization, arguing national identities and economies are encroached on by incessant immigration. Instead, right-wing antiglobalists support nationalism as a cure for the alleged problems caused by the globalization. Right-wing antiglobalism protests against the United Nations (including its Sustainable Development Goals), 15-minute cities, and COVID-19 vaccines as being created or promoted by globalists.

Right-wing antiglobalists frequently use the term globalist as a pejorative and in various conspiracy theories, notably linking with the New World Order conspiracy theory, and as a trope within the new antisemitism movement; although certain right-wing antiglobalist leaders, such as Donald Trump and Javier Milei, also hold pro-Israel principles.

Drug repositioning (also known as drug repurposing, re-profiling, re-tasking, or therapeutic switching) is the repurposing of an approved drug for the treatment of a different disease or medical condition than that for which it was originally developed. This is one line of scientific research which is being pursued to develop safe and effective COVID-19 treatments. Other research directions include the development of a COVID-19 vaccine and convalescent plasma transfusion.

Several existing antiviral medications, previously developed or used as treatments for severe acute respiratory syndrome (SARS), Middle East respiratory syndrome (MERS), HIV/AIDS, and malaria, have been researched as potential COVID-19 treatments, with some moving into clinical trials.

Joe Biden's tenure as the 46th president of the United States began with his inauguration on January 20, 2021, and ended on January 20, 2025. Biden, member of the Democratic Party, had previously served as the 47th vice president from 2009 to 2017 under President Barack Obama, took office after defeating the Republican incumbent president Donald Trump in the 2020 presidential election. Upon his inauguration, he became the oldest president in American history, breaking the record set by Ronald Reagan. Alongside Biden's presidency, the Democratic Party also held their majorities in the House of Representatives and the Senate during the 117th U.S. Congress following the 2020 elections, thereby attained an overall federal government trifecta. Biden entered office amid the COVID-19 pandemic, an economic crisis, and increased political polarization.

Day one actions of his presidency included restoring U.S. participation in the Paris Agreement, revoking the permit for the Keystone XL pipeline and halting funding for the Mexico–United States border wall. On his second day, he issued a series of executive orders to reduce the impact of COVID-19, including invoking the Defense Production Act of 1950, and set an early goal of achieving one hundred million COVID-19 vaccinations in the United States in his first 100 days. The first major legislation signed into law by Biden was the American Rescue Plan Act of 2021, a $1.9 trillion stimulus bill that temporarily established expanded unemployment insurance and sent $1,400 stimulus checks to most Americans in response to continued economic pressure from COVID-19. He signed the bipartisan Infrastructure Investment and Jobs Act, a ten-year plan brokered by Biden alongside Democrats and Republicans in Congress to invest in American roads, bridges, public transit, ports and broadband access.

COVID-19 vaccine hesitancy in the United States is the sociocultural phenomenon of individuals refusing or displaying hesitance towards receiving the COVID-19 vaccine. COVID-19 vaccine hesitancy in the United States can be considered as part of the broader history of vaccine hesitancy.

The Moderna COVID‑19 vaccine, sold under the brand name Spikevax among others, is a COVID-19 vaccine developed by the American company Moderna, the United States National Institute of Allergy and Infectious Diseases (NIAID), and the Biomedical Advanced Research and Development Authority (BARDA). Depending on the jurisdiction, it is authorized for use in humans aged six months, twelve years, or eighteen years and older. The Moderna COVID‑19 vaccine provides protection against COVID-19, which is caused by infection by the SARS-CoV-2 virus. In May 2025, a different version of the Moderna COVID-19 vaccine, with the brand name Mnexspike (mRNA-1283), was approved for medical use in the United States.

Spikevax is designed to be administered in two or three 0.5-mL doses given by intramuscular injection, primarily into the deltoid muscle, at an interval of at least 28 days apart. The World Health Organization advises an eight-week interval between doses to optimize efficacy. Additional booster doses are approved in some regions to maintain immunity. Clinical trials and real-world data have demonstrated the vaccine's high efficacy, with significant effectiveness observed two weeks post-administration of the second dose, offering 94% protection against Covid and robust defense against severe cases. The vaccine's efficacy spans various demographics, including age, sex, and those with high-risk medical conditions.

Community Notes, formerly known as Birdwatch, is a feature on X (formerly Twitter) where contributors can add context such as fact-checks under a post, image or video. It is a community-driven content moderation program, intended to provide helpful and informative context, based on a crowd-sourced system. Notes are applied to potentially misleading content by a bridging-based algorithm not based on majority rule, but instead agreement from users on different sides of the political spectrum.

The program launched on Twitter in 2021 and became widespread on X in 2023. Initially shown to U.S. users only, notes were popularized in March 2022 over misinformation in the Russian invasion of Ukraine followed by COVID-19 misinformation in October. Birdwatch was then rebranded to Community Notes and expanded in November 2022. As of November 2023, it had approximately 133,000 contributors; notes reportedly receive tens of millions of views per day, with its goal being to counter propaganda and misinformation. According to investigation and studies, the vast majority of users do not see notes correcting content. In May 2024, a study of COVID-19 vaccine notes were deemed accurate 97% of the time.

Postural orthostatic tachycardia syndrome (POTS) is a condition characterized by an abnormally large increase in heart rate upon sitting up or standing. POTS in adults is characterized by a heart rate increase of 30 beats per minute within ten minutes of standing up, accompanied by other symptoms. This increased heart rate should occur in the absence of orthostatic hypotension (>20 mm Hg drop in systolic blood pressure) to be considered POTS. POTS is a disorder of the autonomic nervous system that can lead to a variety of symptoms, including lightheadedness, brain fog, blurred vision, weakness, fatigue, headaches, heart palpitations, exercise intolerance, nausea, difficulty concentrating, tremulousness (shaking), syncope (fainting), coldness, pain or numbness in the extremities, chest pain, and shortness of breath. Many symptoms are worsened with postural changes, especially standing up. POTS symptoms may be treated with lifestyle changes such as increasing fluid, electrolyte, and salt intake, wearing compression stockings, slowing down postural changes, exercise, medication, and physical therapy.

POTS is mainly caused by problems in the autonomic nervous system, which controls heart rate and blood flow. This may include blood pooling in the legs instead of returning to the heart, or the heart beating faster to make up for low blood pressure. In other cases, it develops after a viral infection, surgery, trauma, autoimmune disease, or pregnancy. It has also been shown to emerge in previously healthy patients after contracting COVID-19, in people with Long COVID (post-COVID-19 condition), or possibly in rare cases after COVID-19 vaccination, though causative evidence is limited and further study is needed. POTS is more common among people who got infected with SARS-CoV-2 than among those who got vaccinated against COVID-19. About 30% of severely infected patients with long COVID have POTS. Risk factors include a family history of the condition.

2021 (MMXXI) was a common year starting on Friday of the Gregorian calendar, the 2021st year of the Common Era (CE) and Anno Domini (AD) designations, the 21st year of the 3rd millennium and the 21st century, and the 2nd year of the 2020s decade.

Like the year 2020, 2021 saw the year by the COVID-19 pandemic ongoing, due to the emergence of multiple COVID-19 variants. The major global rollout of COVID-19 vaccines, which began at the end of 2020, continued in 2021. Most major events scheduled for 2020 that were postponed due to the pandemic were hosted in 2021, including the 26th United Nations Climate Change Conference (held in Glasgow, Scotland), Expo 2020 (held in Dubai, United Arab Emirates), and sporting events such as UEFA Euro 2020 (held across 11 European countries), the 2020 Summer Olympics and Paralympics (both held in Tokyo, Japan), as well as the 2021 Copa América (held in Brazil).

2022 (MMXXII) was a common year starting on Saturday of the Gregorian calendar, the 2022nd year of the Common Era (CE) and Anno Domini (AD) designations, the 22nd year of the 3rd millennium and the 21st century, and the 3rd year of the 2020s decade.

The year began with another wave in the COVID-19 pandemic, with Omicron spreading rapidly and becoming the dominant variant of the SARS-CoV-2 virus worldwide. Tracking a decrease in cases and deaths, 2022 saw the removal of most COVID-19 restrictions and the reopening of international borders in the vast majority of countries, while the global rollout of COVID-19 vaccines continued. The global economic recovery from the pandemic continued, though many countries experienced an ongoing inflation surge; in response, many central banks raised their interest rates to landmark levels. The world population reached eight billion people in 2022. The year also witnessed numerous natural disasters, including two devastating Atlantic hurricanes (Fiona and Ian), and the most powerful volcano eruption of the century so far. The later part of the year also saw the first public release of ChatGPT by OpenAI starting an arms race in artificial intelligence which increased in intensity into 2023, as well as the collapse of the cryptocurrency exchange FTX.