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COVID-19 Risk, Prevention and Treatment

A Guide for Understanding How to Protect Yourself and Your Community

Last updated November 3, 2021. This page will be updated as our understanding of COVID-19 increases.

On March 11, 2020, the World Health Organization (WHO) declared COVID-19 a pandemic. Since then, millions of people have been infected or died of the virus. At the same time, there has been a pandemic of misinformation and false claims regarding the disease and its origin, transmission, virulence, prevention and treatments. Below is a guide for understanding how to protect yourself and your community. Visit SciCheck, a project of, to learn more.

There is no cure for COVID-19

  • Getting COVID-19 can lead to hospitalization, death and long-term health issues, not to mention you can pass the disease on to others.
  • Only a few evidence-based treatments are available so far.
  • The Food and Drug Administration (FDA) has approved one drug, the antiviral drug remdesivir, and authorized several others that are still being studied. The treatments are for hospitalized patients or those at high risk of severe disease, including hospitalization and death.
  • For example, several monoclonal antibody drugs, including one made by the company Regeneron, are authorized for people at high risk of developing severe COVID-19.
  • The steroid dexamethasone was found in a large randomized controlled trial to benefit hospitalized COVID-19 patients who were ventilated or receiving supplemental oxygen.
  • Another large randomized controlled trial found that fluvoxamine, an antidepressant and obsessive-compulsive disorder drug, reduced the risk of hospitalization when given early to high-risk outpatients.
  • The FDA hasn’t authorized hydroxychloroquine. Randomized controlled trials have found the drug isn’t beneficial in treating hospitalized patients. Whether it can prevent COVID-19 is still being studied.
  • The FDA hasn’t authorized the antiparasitic drug ivermectin. Available data don’t show the drug is effective against COVID-19, but clinical trials are continuing. It is dangerous to self-medicate with large doses of the drug or with ivermectin for animals.

Getting COVID-19 is Risky

  • More than 1 in 500 Americans have died of COVID-19 since the pandemic began.
  • On September 1, 2021, over 94,000 people in America were hospitalized with COVID-19.
  • Older people and those who have certain underlying medical conditions are more likely to get severely ill from COVID-19.
  • Although most people with COVID-19 get better within weeks, some experience ongoing health problems, also known as “long COVID.”
  • More than 1 in 3 COVID-19 patients had long COVID symptoms between three and six months after their initial diagnoses, according to one study of more than 270,000 patients.

COVID-19 is especially risky for those who are pregnant:

  • The Centers for Disease Control and Prevention (CDC) says pregnant and recently pregnant people are “more likely to get severely ill from COVID-19 compared with non-pregnant people.”
  • Pregnant people who contract COVID-19 are at increased risk for preterm birth, the CDC says.

Getting infected with COVID-19 is far riskier than getting vaccinated:

  • Tens of thousands of people participated in the vaccine trials. The New England Journal of Medicine published the peer-reviewed results.
  • The trial results and subsequent monitoring for adverse effects as the vaccines have been rolled out have shown that the benefits of vaccination outweigh the risks.
  • While regulators will continue to monitor for safety, adverse reactions to vaccines virtually always occur within several months. This is different from medications, many of which are taken repeatedly and can cause side effects over time.
  • As of mid-September, there were 2,075 COVID-19 deaths per 1 million population in the United States.
  • More than 189 million Americans have been fully vaccinated, and more than 218 million have received at least one dose.
  • And the risk of a serious adverse event after vaccination is rare. For instance, there have been 2 to 5 cases of anaphylaxis, a life-threatening allergic reaction, per 1 million vaccine doses administered. Vaccination sites can immediately treat that reaction.

Vaccinated immunity is preferable to immunity conferred by getting infected:

  • It’s true that natural immunity can provide protection, but that requires infection and the risk of getting sick. It’s also not known how long immunity lasts, and a small proportion of people who had infections may not develop much immunity.
  • Studies show the vaccines give an immunity boost to those who were previously infected.

The benefits of vaccination against COVID-19 are significant:

  • Vaccination significantly reduces the chances that the recipient will get symptomatic COVID-19 or be hospitalized or die of the disease.
  • According to the CDC, after delta became the most common variant, unvaccinated or not fully vaccinated Americans are…
    more likely to become infected with COVID-19
    more likely to require hospitalization for COVID-19
    more likely to die from COVID-19

    …than fully vaccinated Americans.

Vaccines do work against the delta variant:

  • The delta variant is more than twice as contagious as the original virus.
  • The vaccines may be less effective against the delta variant but are still very good at preventing severe illness, hospitalization and death.

Data show the vaccine is safe before, during and after pregnancy:

  • The American College of Obstetricians and Gynecologists and the Society for Maternal-Fetal Medicine recommend “all pregnant individuals be vaccinated against COVID-19.”
  • The CDC also recommends that pregnant people be vaccinated. The agency found no increased risk of miscarriage among those who have been immunized.
  • The safety data after millions of vaccinations, and studies involving thousands of pregnant people, have indicated vaccination against COVID-19 is safe during pregnancy.
  • There is no evidence of fertility problems caused by the vaccines, in either women or men.
  • Vaccinations might help protect babies, as antibodies against the coronavirus have been detected in umbilical cord blood and breast milk of vaccinated mothers.

Vaccines have been preventing disease for more than 100 years

Smallpox, polio, measles, mumps, rubella, whooping cough, chickenpox and diphtheria are all no longer a threat thanks to vaccination.

Before they are authorized, vaccines go through many forms of independent scientific review

The CDC and FDA continue to monitor the safety of vaccines after they are authorized

Masking, physical distancing and good ventilation are still needed indoors in public because vaccines are not 100% effective. Those who are fully vaccinated may still get infected and fall ill with COVID-19, although their symptoms are likely to be less severe.

How these vaccines work

The vaccines trigger an immune response against the coronavirus’s spike protein, which sits on the surface of the virus and is what it uses to enter cells.

The vaccines deliver instructions to cells to produce a harmless protein, similar to the coronavirus’s spike protein.

The Pfizer and Moderna vaccines deliver these instructions using modified messenger RNA, or mRNA. The Johnson & Johnson vaccine uses a modified, harmless adenovirus.

When cells read the instructions, they make the harmless protein.

That triggers the immune system, generating protective antibodies and activating other immune cells known as T cells.

If you are later exposed to the coronavirus that causes COVID-19, your immune system can recognize it and protect you.

The vaccines don’t alter a person’s DNA. The Pfizer and Moderna vaccines don’t enter the nucleus of a cell, where DNA is. The J&J vaccine doesn’t integrate into human DNA.

Masking minimizes infection and transmission:

This image from the National Institute of Standards and Technology illustrates airflow when coughing with and without a mask. Credit: M. Staymates/N. Hanacek/NIST
  • Fully vaccinated people, even those showing no symptoms, may still be able to spread the virus to others.
  • Wearing a high-quality, well-fitted mask in indoor public places reduces your chances of contracting or spreading the coronavirus.