COVID-19 Vaccines

SARS-CoV-2 Vaccine

Vaccines build long-lasting, active immunity against disease by helping the body’s ability to fight a virus. There may be cases in which the vaccine does not prevent you from contracting the COVID-19 virus. However, if you do catch it, the vaccine could keep you from getting seriously ill or prevent complications.

Reasons to get vaccinated against COVID-19

  • It helps you build immunity against SARS-CoV-2, the virus that causes COVID-19.
  • The vaccine could keep you from getting seriously ill, prevent complications, or die from the disease.
  • While each vaccine works differently, all COVID-19 vaccines elicit an immune response so your body remembers how to fight the virus in the future.
  • Prevent the virus that causes COVID-19 from spreading and replicating, contributing to herd immunity.
Vacunas COVID-19 |

What to know about the different COVID-19 vaccines.

Information about the different vaccines, how they work, how many doses are needed, what the possible side effects are, and who should not get the vaccine.

Vacunas COVID-19

COVID-19 Vaccine Dose

Learn why the COVID-19 vaccine is applied in one or two doses and what is the official recommendation for its application, combining, or not combining the different vaccines.

How do COVID-19 vaccines work?

Any vaccine is intended to generate immunity against a disease by producing antibodies that activate the body’s natural defenses, strengthening the immune system.

The main types of COVID-19 vaccines that are currently available or in large-scale clinical trials include the following:

Messenger RNA (mRNA) vaccine.

mRNA vaccines are a new type of vaccine that teaches our cells to make an S protein, which triggers an immune response that produces antibodies, protecting us from infection if the real virus enters our bodies.

This vaccine cannot cause an infectious disease such as COVID-19 since it does not contain the live virus that causes COVID-19.

Vector-based vaccine.

Viral vector vaccines contain a modified version of another virus (viral vector) to instruct our cells and make copies of protein S. Once it has protein S, the immune system responds by creating antibodies and defense white blood cells. If you get infected with the COVID-19 virus, the antibodies fight the virus.

Viral vector vaccines cannot get you infected with the COVID-19 virus or the viral vector virus. In turn, the genetic material they provide does not become part of your DNA.

Protein subunit vaccines.

This type of COVID-19 vaccine contains harmless S proteins. Once the immune system recognizes the S proteins, it creates antibodies and defense white blood cells.

COVID-19 variants, do vaccines work for the new variants?

When a virus has one or more mutations they are called ``variants`` of the original virus. Some of the worrying variants of COVID-19 are Alpha. (B.1.1.7), Beta (B.1.351), Gamma (P.1), Delta (B.1.617.2).

Vaccines against COVID-19 continue to be effective with severe and mild forms, although they decrease by a certain percentage. Remember that receiving a dose does not grant immediate immunity, be cautious and comply with the complete vaccination schedule.

Vacunas COVID-19

Differences between variants and the original virus of COVID-19

Increased virulence or change in the clinical presentation
of the disease.

Decreased effectiveness of available vaccines and treatments

Variantes COVID-19 | Virus SARS-CoV-2

Original Virus (SARS-CoV-2)

A sick person can infect up to 2 people.

Variante Alfa | Variantes COVID-19

Alpha variant

A sick person can infect up to 4 people.

Variante Delta | Variantes COVID-19

Delta variant

A sick person can infect up to 9 people.

Increase in transmissibility.

Increased virulence or change in the clinical presentation of the disease.

Variante Delta | Efectividad Vacunass COVID-19

Decreased effectiveness of available vaccines and treatments.

COVID-19 (SARS-CoV-2 original) Una persona enferma puede contagiar hasta 2 personas.
Variante Alfa  una persona enferma puede contagiar hasta 4 personas
Variante Delta  una persona enferma puede contagiar hasta 9 personas

Increase in transmissibility.

6 precautions against COVID-19 variants

Precauciones Variante Delta | COVID-19

Keep a distance of 1.5 meters

Precauciones Variante Delta | COVID-19

Perform hand hygiene on an ongoing basis.

Precauciones Variante Delta | COVID-19

Continue to use facemasks of at least triple layer quality

Precauciones Variante Delta | COVID-19

Keep the windows open

Precauciones Variante Delta | COVID-19

Get vaccinated when it’s your turn

Precauciones Variante Delta | COVID-19

Coughs and sneezes with the upper arm even with a mask

Frequently asked questions about vaccination

The COVID-19 vaccine Based on scientific information of each of the vaccines already authorized by emergency against COVID-19, it can prevent almost 100% of serious cases or that require hospitalization due to infection by SARS-CoV-2 Increase the number of people in the community who are protected from getting COVID-19 Prevent the virus that causes COVID-19 from spreading and replicating, allowing it to mutate and possibly become more resistant to vaccines.
  • The Pfizer-BioNTech vaccine is 95% effective after the second dose in preventing symptomatic COVID-19. This vaccine is for people over 16 years old. It is made up of two doses that are applied 21 days apart.
  • The Moderna vaccine is 94.5% effective after the second dose in preventing symptomatic COVID-19. This vaccine is for people over 18 years old. It is made up of two doses that are applied 28 days apart.
  • The Janssen/Johnson & Johnson vaccine is 66% effective after the first dose in preventing symptomatic COVID-19. This vaccine is for people over 18 years old. It is made up of one dose.
  • The AstraZeneca and Oxford University vaccine is 63% effective after the second dose in preventing symptomatic COVID-19. This vaccine is for people over 18 years old. It is made up of two doses that are applied 21 days apart.
  • The Sputnik V vaccine is 92.0% effective after the second dose in preventing symptomatic COVID-19. This vaccine is for people over 18 years old. It is made up of two doses that are applied 21 days apart.
These vaccines are authorized as an emergency, the vaccination process in general takes years in its different phases but due to the pandemic these were shortened. The documentation requested for the administrative part and the time to get financing were urgent procedures, the time it took to enroll patients was incredibly fast. Follow-up was as meticulous as with any other vaccine, and data is now available from several months of follow-up of patients who received the vaccine or placebo. Vaccine side effects are generally local and mild, such as pain where it was applied, fever, chills, myalgias, and arthralgias. There is an extremely low percentage of allergic reactions and this will have to do with certain components of each vaccine and each person’s predisposition.
Vaccines against COVID-19 were developed based on S protein before the mutations identified in these variants. Until the latest scientific reviews, these do protect against the new variants, although this does not exempt us from having a new variant in the future for which the vaccines would not be effective. More research is needed.
No. It is important to maintain preventive measures before and after the vaccine, since for you to be protected you need to first have the complete scheme of each vaccine brand against COVID-19 and then allow our immune system to generate antibodies.
A COVID-19 vaccine can have mild side effects after the first or second dose. Among them:
  • Pain, redness, or swelling where the injection was given
  • Fever
  • Fatigue
  • Headache
  • Muscle pain
  • Chills
  • Joint pain
  • Nausea and vomiting
  • General discomfort
  • Swollen lymph nodes
They usually keep you in observation after getting the vaccine for 15 to 30 minutes to see if you have an immediate reaction. Mild side effects can last one to two days. It is important to notify your doctor if you detect any other symptoms other than the ones referred to.
Allergic reactions occur after the application of the COVID-19 vaccine within an average of four hours after receiving the first dose of the vaccine, which can be:
  • Constant wheezing or shortness of breath.
  • Swelling of the lips, eyes, or tongue.
  • Redness, swelling, or itching in areas of the body other than the arm where the vaccine was given.
  • If you have signs of an allergic reaction, seek care immediately.
  • Inform your doctor about the reaction, even if it is gone or you didn't need emergency care.
It is not recommended to take a pain killer before or after the application of the COVID-19 vaccine if you do not have any symptoms; if a mild side effect begins, you can take a pain killer, as long as you have no health reason that prevents you from taking it for no more than 48 hours.
Vaccines rarely cause long-term side effects. Based on scientific evidence, so far no long-term side effects have been found, but since they are emergency authorized vaccines this is still being monitored. You can find information at (https://vaers.hhs.gov/data.html). Vaccine Adverse Event Reporting System
What has been seen in global databases are:
  • People over 75 years old
  • Poorly controlled diabetics
  • Poorly controlled hypertensive patient
  • Heart disease
  • Chronic Obstructive Pulmonary Emphysema (COPE)
  • Immunosuppression Diseases
  • People with obesity
  • Asthmatics
It is advisable not to apply the COVID-19 vaccine if you have a history of serious allergic reactions related to any component of the COVID-19 vaccine that you will get. If you have a history of a mild allergic reaction to other vaccines, it is important that you notify the person that will give you the vaccine so that it puts you in observation for 30 minutes.
Yes, if you have a prior medical condition, you can receive the COVID-19 vaccine, as long as you have not had an allergic reaction to the COVID-19 vaccine or any of its components. However, there is little information on the safety of COVID-19 vaccines in people who have a weakened immune system or have autoimmune conditions.
There is no research on the safety of COVID-19 vaccines for pregnant or breastfeeding women. But if you are pregnant or breastfeeding, and you are part of a group that is recommended to get a COVID-19 vaccine, you may choose to get it. Talk to your doctor about the risks and benefits.
There is still no COVID-19 vaccine for children under the age of 16. Several companies have begun enrolling 12-year-old children in clinical trials for COVID-19 vaccines. Studies that include younger children will begin soon.
Having COVID-19 may offer some protection or natural immunity against reinfection. But scientific studies show that the vaccine gives greater protection against COVID-19. It is recommended to apply the COVID-19 vaccine 14 days after the onset of symptoms in mild cases and up to 30 days in severe cases.
Remember that if you are fully vaccinated and after the period that each vaccine refers to to generate antibodies, your risk of contracting COVID-19 could be low. But if you do get infected, you could spread the virus to other people, even if you don't have signs or symptoms, so we recommend:
  • To meet other fully vaccinated people two weeks after the second dose indoors, without wearing masks and without avoiding close contact.
  • However, vaccinated people should continue to take safety precautions, such as wearing a mask and avoiding close contact with others (approximately 2 meters), when they are:
    • In public
    • Gathered with people who are not vaccinated and are at a higher risk of serious illness from COVID-19
    • Gathered with people living with someone who is not vaccinated and is at a higher risk of serious illness from COVID-19
    • Gathered with unvaccinated people living in different households