COVID-19 Vaccines

COVID-19 Vaccine

En español

COVID-19 vaccines are now being administered to people throughout the United States. Public health officials hope much of the nation will be inoculated this year to stop the coronavirus spread. Here are answers to some frequently asked questions.

  • What vaccines are available?
  • Two vaccines have been authorized for use in the United States. The first was developed by the pharmaceutical firms Pfizer and BioNTech, and it consists of two shots, given three weeks apart. The second available vaccine, Moderna, was developed by a Massachusetts biotechnology company in partnership with the National Institute of Allergy and Infectious Diseases. It consists of two shots, given 28 days apart.
  • How do they work?
  • Both vaccines employ messenger RNA technology, which has been approved by the Food and Drug Administration (FDA) for human use. The vaccines contain molecular instructions that prompt your cells to create a protein in response to a protein on the surface of the coronavirus. In that way, the vaccines prepare your immune system to ward off the virus if it should try to invade your healthy cells.
  • The vaccines were developed very quickly. Are they safe?
  •  COVID-19 vaccines were developed in record time for explainable reasons. Modern scientific tools are much faster than older technology, and scientists around the world worked together to develop a vaccine to fight the global pandemic. The vaccines were tested in large, randomized clinical trials with tens of thousands of people of different ages, races and ethnicities, some with various medical conditions, which allowed researchers to quickly gather data and answer key questions about safety and protection.

    Both vaccines passed rigorous safety reviews by the FDA. The benefits of the vaccines were determined to far outweigh the harms associated with acquiring a COVID-19 infection. The Centers for Disease Control and Prevention (CDC) have several systems in place to ensure safety and to continue to collect information on people’s experiences with the vaccine.
  • Will I suffer side effects?
  • Most people do not have serious problems after being vaccinated. Your arm may be sore, red or warm to the touch where the shot was given. Some people report flu-like symptoms, such as fever, chills and headaches, especially after the second vaccine. These side effects are normal signs that your immune system is building up protection from the disease. If symptoms increase after 24-48 hours, contact your health care provider.
  •  Do some people have allergic reactions to the shot?
  • Allergic reactions to vaccinations can occur. The most serious reaction is anaphylactic, which is severe and very rare. Possible symptoms of anaphylaxis include a skin rash, nausea, vomiting, difficulty breathing and shock, generally within minutes of receiving the vaccine. Anaphylaxis can be quickly reversed with an intramuscular injection, such as epinephrine. People who have had previous severe allergic reactions to other types of vaccines should talk to a medical professional before getting the COVID-19 vaccine.
  •  Will I still need to wear a mask and socially distance after being vaccinated?
  • Yes. The vaccine does not begin to protect you immediately, and scientists are still researching whether the shot prevents people from shedding the virus and infecting others. For now, the CDC recommends vaccinated people wear a mask over their nose and mouth, avoid crowds and stay at least six feet from others.
  •  How much will the vaccine cost?
  • The federal government is providing the vaccine at no charge to people living in the United States. However, your vaccination provider may bill your insurance company, Medicaid or Medicare for an administration fee.
  • Why do some people get access to the vaccine in some areas, but not in others? 
  • Vaccines have only recently been distributed by the federal government to each of the states. The first doses were aimed at healthcare workers and first responders, so the largest number of doses were distributed to healthcare delivery systems, not to counties. Distribution to counties is likely to play a more predominant role as doses are released for use in the general population.
  • Why can a worker get the vaccine, but not his or her family members?
  • States and counties are rolling out vaccines based on the tier system which is prioritizing certain workers who are more likely to be exposed to the virus at work. For this reason, some workers may receive the vaccine before their family members. Since it’s not clear whether vaccinated people can still infect others, it’s important for everyone to continue masking and keeping their distance.
  • Who has access to the data provided when people get vaccinated? 
  • The California Department of Public Health is responsible for monitoring vaccine use, and they have a data-use agreement with the CDC. According to the agreement, California will not share information that would allow the federal government to identify an individual based on the information they are given. Information provided will include a person’s birth year, sex and county where the vaccine was administered. Vaccine eligibility is not based on residency or immigration status.

More COVID-19 vaccine information in multiple languages is available from the Centers for Disease Control and Prevention.