Frequently asked questions about vaccination in Mexico
. How many vaccines against COVID-19 are there?
Vaccines generally require years of research and testing before reaching the public, but since 2020 and in the face of the COVID-19 pandemic, scientists around the world are working to produce safe and effective vaccines against SARS-CoV-2 in a timely manner. record. There are currently hundreds of research groups developing and testing vaccines of various types. As of January 2021, 66 vaccines are already in human clinical trials, and 20 have reached the final stages of testing.
The most advanced vaccines have already been approved for emergency use by several countries. Among these are:
- Pfizer / BioNTech
- Modern
- Sputnik VU
- AstraZeneca / Oxford
- CanSinoBIO
- Synopharm
- A nephew
- Johnson & Johnson (Janssen)
- Covaxine
In Mexico, vaccines that have been approved by COFEPRIS (Federal Commission for the Protection against Health Risks) for use in the health emergency are:
- Pfizer / BioNTech
- AstraZeneca / Oxford
- Sputnik VU
- A nephew
- CanSinoBIO
- Covaxine
- Johnson & Johnson (Janssen)
2. What are the components of COVID vaccines?
Each vaccine has a formulation that consists, in general terms, of the antigen or protein of the SARS-CoV-2 virus that will be responsible for provoking the immune response (defense mechanism) of the organism and against which antibodies and cells are produced. activated. Additionally, substances necessary to maintain the stability of the antigen before and after application are included, as well as to stimulate the response capacity of the immune system after the application of the vaccine.
The components of the four vaccines currently available for application are described below:
The COVID-19 vaccine Pfizer / BioNTech contains the following components:
- messenger RNA (ribonucleic acid): the only active component of the vaccine. The mRNA molecules contain the genetic material that provides the body with instructions on how to make the antigen: a virus protein called spike or spike that will trigger the immune response.
- Lipids: Its main function is to protect the mRNA molecule and provide an outer covering that helps the mRNA enter cells.
- Sales that ensure the stability of the vaccine once injected into the body.
- Sugar (sucrose): This component helps molecules maintain their shape during freezing.
The COVID-19 vaccine Modern contains:
- Messenger RNA (ribonucleic acid): Like the Pfizer BioNTech vaccine, it also uses this technology to generate antibodies against COVID-19 that are responsible for triggering the immune response.
- Lipids: to help transport mRNA to cells.
- Stabilizing substances such as Sales y sucrose.
The vaccine AstraZeneca / Oxford contains:
- A viral vector called Adenovirus which is weakened so that it does not cause illness in people. This virus carries with it the genetic material (similar to the mRNA of the Pfizer and Moderna vaccines), which will be responsible for producing the SARS-CoV-2 spike protein.
- In addition to the genetic material vector, the vaccine includes substances to maintain its stability.
The vaccine Sputnik VU, developed by the Gamaleya National Center, contains:
- A viral vector, Adenovirus 26 in the first dose and Adenovirus 5 in the second dose. Both viruses are weakened so as not to cause disease in people, but capable of carrying the genetic material of the virus, specifically the gene that carries the instructions so that human cells can produce the SARS-CoV-2 spike protein.
- In addition to the genetic material vector, the vaccine includes substances to maintain its stability.
The vaccine CanSinoBio contains:
- A viral vector, Adenovirus 5, which is a weakened virus so as not to cause disease in people, but capable of carrying the genetic material of the virus, specifically the gene that carries the instructions so that human cells can produce the spike protein of SARS-CoV-2
- In addition to the genetic material vector, the vaccine includes substances to maintain its stability.
- This vaccine is given in a single dose
The vaccine Johnson & Johnson (Janssen) contains:
- A viral vector, Adenovirus 26, which is a weakened virus, as in the CanSinoBio vaccine, so as not to cause disease in people, capable of carrying the genetic material of the virus, specifically the gene that carries the instructions so that human cells can produce the spike protein of SARS-CoV-2
- In addition to the genetic material vector, the vaccine includes substances to maintain its stability.
- This vaccine is given in a single dose
Vaccines against COVID-19 Nephew Biotech y Synopharm (developed by private Chinese companies) and *Covaxin, (by the National Institute of Virology Bharat Biotech), contain the SARS-CoV-2 virus inactivated using a chemical substance called beta-propiolactone that prevents the virus from reproducing (replicating) inside human cells, preventing it from causing the disease. . However, the spike protein remains intact and has all the capacity to stimulate the body's immune response to generate protection. In addition to the inactivated virus, the vaccine contains an aluminum-based substance called “adjuvant” that serves to further stimulate the immune system to respond appropriately to the vaccine.
1. Do all vaccines work the same?
There are various types of vaccines currently developed or in development against SARS-CoV-2, the virus that causes COVID-19. The main mechanisms of action of vaccines are described below:
- Nucleic acids: Vaccines that transport one or more coronavirus genes into human cells to produce viral proteins that trigger the immune response.
- viral vectors: Vaccines that contain viruses designed to carry coronavirus genes. Some viral vector vaccines enter cells and cause them to produce viral proteins. Other viral vectors replicate slowly and carry coronavirus proteins on their surface.
- Protein based: Vaccines that contain complete coronavirus proteins or protein fragments, but not genetic material. When viral proteins are detected, the immune response is triggered and antibodies and defense cells are generated.
- Inactivated or attenuated viruses: Vaccines created from weakened coronaviruses or coronaviruses that have been inactivated with chemicals. These viruses are capable of triggering the immune response but not causing the disease.
2. How do COVID vaccines work?
There are various types of vaccines currently developed or in development against SARS-CoV-2, the virus that causes COVID-19. Among the available vaccines are the following:
Nucleic acid vaccines
Both vaccines Pfizer / BioNTech like Modern, use the nucleic acid messenger RNA (mRNA), a molecule with the instructions for the production of proteins by cells. In the case of these vaccines, the mRNA has specific instructions to produce a viral protein called S protein, spike, which is essential for the virus to infect cells.
After vaccination, the cells receive the instructions and begin to make the S protein and display it on their surface. The immune system then identifies the viral protein and triggers the immune response, producing antibodies and defense cells.
Viral vector vaccines
For the vaccine AstraZeneca, researchers added the gene that produces the S protein of the SARS-CoV-2 coronavirus to another virus called adenovirus. In this case, a modified version of a chimpanzee adenovirus, known as ChAdOx1, is used, which is harmless to humans. This virus can enter cells, but it cannot replicate within them. Once inside the cell, the gene produces the viral protein which is presented on the surface of the cell, triggering the body's immune response.
Like the vaccine AstraZeneca, the vaccine from the Gamaleya National Research Center for Epidemiology and Microbiology of Russia, Sputnik V, the vaccine CanSinoBIO and Johnson & Johnson (Janssen) They work through a viral vector. The vaccine uses two variants of adenovirus, a type of virus that causes colds, to which the gene with instructions for producing the coronavirus spike protein was included. The two types of adenovirus, Adenovirus 5 or Ad5 and Adenovirus 26 or Ad26, are designed to be able to invade cells to produce the spike protein, but they are not capable of reproducing themselves. The strategy of using two types of adenovirus seeks to prevent the body's immune response from preventing the second dose of the vaccine from working properly.
Inactivated virus vaccines
The vaccines Nephew Biotech, Synopharm y Covaxine They are inactivated virus vaccines that use the “killed” version of the coronavirus that causes COVID-19.
Inactivated vaccines usually do not provide as strong protection as live vaccines. Multiple doses over time (booster shots) may be needed to have continued immunity against the disease.
3. Do all vaccines give the same protection?
No. According to published experiments and research, after the second dose, or the single dose where appropriate, the effectiveness of the approved vaccines is as follows:
- Pfizer / BioNTech It has an efficiency of 95%
- Modern by 94.5%
- SputnikV by 91.4%
- Covaxine by 81%
- Synopharm by 79%
- AstraZeneca by 76%
- CanSinoBio by 68.8%
- Johnson & Johnson (Janssen) by 67%
- A nephew by 50.38%
4. How do I know a vaccine is safe?
The vaccine development and production process takes special account of the evaluation that each one of them is safe and generates the necessary protection against the disease. To do this, tests, known as clinical trials, are carried out on groups of people.
These clinical trials are currently being carried out in various parts of the world to evaluate all the vaccines in development against COVID-19 with the participation of tens of thousands of people. These trials generate scientific data and information that is used by regulatory bodies, such as COFEPRIS in Mexico or FDA in the United States, to determine the safety and effectiveness of the vaccine.
Once a vaccine is authorized or approved for use by the regulatory authorities of each country, safety control systems are activated, which serve to continue monitoring the occurrence of possible side effects. Through this continuous monitoring we seek to detect possible adverse effects that may not have occurred in clinical trials. If an unexpected adverse event is observed, particularly if it is serious, groups of expert scientists quickly study it to evaluate whether it is a true safety problem and determine whether or not the use of the vaccine can be maintained.
5. Are all vaccines safe?
Each vaccine producer publishes the results of its clinical trials where evidence of safety, efficacy, adverse effects and contraindications is presented based on the results of the experiments carried out.
This information, along with other details of the vaccine such as formulation and ability to generate protection, is submitted to the regulatory authorities to request authorization for use in each country. Authorization for use will then depend on evidence that a vaccine is safe and effective in protecting the population against the disease.
In Mexico, COFEPRIS has already granted authorization for emergency use to vaccines Pfizer/BionTech, AstraZeneca, Sputnik VU, A nephew, CanSinoBIO, Covaxine y Johnson & Johnson (Janssen) which means that the application of these vaccines is allowed only as part of the response to the COVID-19 health emergency.
1. Do all vaccines require two doses?
Vaccines Pfizer, AstraZeneca, Modern, Sputnik VU y A nephew require two doses. The vaccines of CanSinoBIO y Johnson & Johnson They require only one dose.
The currently authorized COVID-19 vaccines require 2 doses for maximum protection:
- Pfizer / BioNTech: doses should be applied with an interval of 3 weeks (21 days)
- Modern: doses should be applied with an interval of 1 month (28 days)
The second dose should be given as close as possible to the recommended interval of 3 weeks or 1 month. However, there is no maximum interval between the first and second doses of either vaccine. The second dose should not be given before the recommended interval.
- AstraZeneca / Oxford: The two doses must be applied with an interval of 28 days.
- Sputnik V: The second dose should be applied 21 days after the first.
- A nephew: The second dose should be given 2 weeks after the first.
- Covaxine: The second dose should be applied with an interval of 28 days.
2. Why is the application of the second dose of the vaccine important?
One of the main elements of the vaccine development process is determining the volume and number of doses that people should receive to achieve the desired level of protection against the disease. This ultimately determines the vaccination schedule for each vaccine, which is submitted to the regulatory authorities in each country.
Therefore, to achieve protection against the disease, it is important to comply with the number of doses and interval between each one established by the producer and authorized by the regulatory authority.
3. What is the maximum time I have to get the second dose of the vaccine?
According to the United States Centers for Disease Control (CDC), the maximum time to receive the second dose of any vaccine is 6 weeks after the first dose.
- Pfizer / BioNTech: doses should be applied with an interval of 3 weeks (21 days)
- Modern: doses should be applied with an interval of 1 month (28 days)
- AstraZeneca / Oxford: the two doses must be applied with an interval of 1 month (28 days)
- Sputnik V: The second dose must be applied 21 days after the first
- A nephew: Doses should be applied with an interval of 2 weeks (14 days)
- Synopharm: Doses should be applied with an interval of 3 weeks (21 days)
- Covaxine: The second dose should be applied with an interval of 28 days.
The Moderna COVID-19 (mRNA-1273) vaccine: what you need to know (who.int)
4. What happens if I only receive one dose?
Failure to complete the recommended vaccination schedule may cause the expected level of immunological protection against the disease to not be achieved. Studies are currently being carried out to measure the level of protection conferred by the partial and complete schedules of the different vaccines against COVID-19.
At this time, scientific evidence supports the schemes defined by producers and authorized by regulatory agencies such as COFEPRIS. Therefore, it is important that all people who receive their COVID-19 vaccines have their complete schedules.
The Moderna COVID-19 (mRNA-1273) vaccine: what you need to know (who.int)
5. If I received the first dose with the Pfizer vaccine, can I get the second dose with another vaccine?
To date, there is no scientific evidence to ensure that the different vaccines against COVID-19 can be interchangeable with each other, since the safety and effectiveness of a mixed product scheme has not been evaluated. Therefore, the current indication is that both doses of the regimen should be completed with the same product.
The Moderna COVID-19 (mRNA-1273) vaccine: what you need to know (who.int)
1. After receiving the vaccine, how long am I protected?
For the vaccine Pfizer, adequate levels of protection against the disease are achieved, in the 95% of those vaccinated, after two doses, 28 days after the first dose was applied.
Vaccine protection AstraZeneca, in its optimal scheme, occurs in the 76% of those vaccinated after two doses, between two and three weeks after application.
The Russian vaccine Sputnik V, reaches an effectiveness of 73.1% from the first dose and 91.6% when applying the second dose (day 21).
For the company's CoronaVac vaccine A nephew, an effectiveness of 50.6% is achieved after the application of the second dose, 14 days after the first.
The vaccine Johnson & Johnson (Janssen), reaches an effectiveness of 67% from day 14 of the application of the single dose.
The vaccine CanSinoBIO, reaches an effectiveness of 68.8% from day 28 of the application of the single dose.
2. If I have already been vaccinated, can I stop wearing a mask and can I stop social isolation?
There is still no scientific evidence on the duration of protection against COVID-19 conferred by the different vaccines. In addition to the individual effect, the protection provided by the vaccine also depends on population considerations such as the number of vaccinated people in a community and how this affects the spread of the virus.
Considering the above, there are some observations that indicate that a vaccinated person can be contagious, even if they do not already develop the disease. The current recommendation is that all prevention and precautionary measures must be maintained to avoid contagion: physical distancing, use of face masks, hand hygiene and strict isolation of people with symptoms or contact of positive cases.
1. Can I get the COVID vaccine at the same time I receive other vaccines?
While scientific evidence is currently limited, it does not appear that COVID-19 vaccines interfere with the immune response to other vaccines and vice versa. However, until other information is available, it is recommended wait 14 days after receiving the COVID-19 vaccine to receive another vaccine. Likewise, you must wait 14 days to receive the COVID-19 vaccine after receiving any other vaccine.
1. Can the COVID vaccine be applied to children and adolescents?
Approvals from regulatory authorities depend on evidence of safety and efficacy presented by vaccine developers and producers. Currently, all the information derived from clinical trials has been the experience in the population over 16 years of age and, therefore, No vaccine has been authorized for use in people under that age.
Currently, clinical trials of several vaccines have already begun in populations between 6 months and 18 years of age, so it is expected that by the end of 2021 there will be sufficient evidence on the safety, effectiveness and practical aspects of vaccination. of this population against the coronavirus. They will subsequently be authorized in younger populations, once there is confidence that the vaccine will not cause any serious adverse events in children.
2. If I am pregnant, can I get the vaccine?
Vaccines are considered one of the safest medical products with the greatest benefit for people's health. Therefore, pregnant and lactating women can choose to apply the vaccine in a high-risk scenario. If you have doubts about vaccination during pregnancy, it is advisable to consult a health professional.
3. If I am breastfeeding, can I get the vaccine?
While there is no evidence that COVID-19 vaccines can cause harm to nursing babies, there is not yet enough data to support widespread vaccination of mothers who are breastfeeding their babies. However, breastfeeding women who are part of a group recommended to receive the COVID-19 vaccine (for example, healthcare personnel at high risk of exposure to the virus or with comorbidities) may choose to be vaccinated. If you have questions about vaccination and breastfeeding, it is advisable to consult a health professional.
4. Can I get the AstraZeneca/Oxford University vaccine even if I am over 65?
The vaccine developed by AstraZeneca/Oxford University It can be used by anyone over 18 years of age. The results of the clinical trials carried out demonstrated that the vaccine is safe and effective in adults over 65 years of age. It is very important that this age group be vaccinated against COVID-19 as they have a high risk of serious illness or death from the disease, situations that are prevented with the application of the vaccine.
5. Can I get vaccinated if I am a person living with HIV?
The vaccine developed by AstraZeneca/Oxford University It can be used by anyone over 18 years of age. The results of the clinical trials carried out demonstrated that the vaccine is safe and effective in adults over 65 years of age. It is very important that this age group be vaccinated against COVID-19 as they have a high risk of serious illness or death from the disease, situations that are prevented with the application of the vaccine.
6. Can I get vaccinated if I am a person who suffers from some type of immune alteration, whether due to treatment (for example immunosuppressants or chemotherapy) or illness?
In accordance with the recommendations for the use of the vaccine AstraZeneca/Oxford University published by the World Health Organization, since this vaccine cannot be reproduced in the body, it can be administered to people who suffer from some alteration of immunity, immunodeficiency or immunosuppression.
7. Can I get vaccinated if I am a person who suffers from an autoimmune disease (for example, celiac disease, type 1 diabetes, rheumatoid arthritis, lupus erythematosus, multiple sclerosis)?
In accordance with the recommendations for the use of the vaccine AstraZeneca/Oxford University published by the World Health Organization, since this vaccine cannot be reproduced in the body, it can be administered to people with autoimmune conditions.
1. How long does the vaccine protection last?
It is not known how long the immunity conferred by a COVID-19 vaccine will last. This is because more data is needed from ongoing and additional long-term studies to understand how long protection lasts after vaccination.
2. Will we have to get vaccinated every year?
European Union authorities will coordinate independent studies on the real-life use of COVID-19 vaccines, to gather more information on their safety and long-term benefit in the general population. The results of these long-term studies will inform future vaccination strategies.https://www.ema.europa.eu/en/human-regulatory/overview/public-health-threats/coronavirus-disease-covid-19/treatments-vaccines/covid-19-vaccines-key-facts#how-long-will-immunity-from-a-vaccine-last?-section
1. If I already got COVID, can I get the vaccine?
People who have already had COVID-19 or tested positive may benefit from the vaccine. There is currently not enough information available to say whether people are protected against COVID-19 after having it (natural immunity) or for how long. Preliminary evidence suggests that la natural immunity may not last long, but more studies are needed to better understand this.
Other sources mention that due to the serious health risks associated with COVID-19 and the fact that reinfection is possible, it is advisable to get vaccinated. If you were treated for COVID-19 symptoms with monoclonal antibodies or convalescent plasma, you should wait 90 days to apply the corresponding vaccine. Talk to your doctor if you are not sure what treatments you received, or if you have more questions about getting vaccinated against COVID-19.
According to data published by the World Health Organization, reinfection with SARS-CoV-2 is considered rare in the first 6 months after symptomatic infection. Therefore, while people who have had COVID-19 can safely receive the vaccine, it is recommended to wait 6 months after illness to receive the first dose of the vaccine.
2. How long after I got COVID can I get vaccinated?
The application of the vaccine should be postponed in people who have recently had COVID-19 and still have symptoms of this condition. Therefore, people with PCR-confirmed disease and symptoms should wait for symptoms to disappear before receiving the first dose of the vaccine.
3. Which lasts longer, immunity after having COVID or protection from COVID vaccines?
The protection someone gets from having an infection (called “natural immunity”) varies depending on the disease and varies from person to person. Because this virus is new, we don't know how long natural immunity might last. Current evidence suggests that getting the virus again (reinfection) is rare in the 90 days after first infection with the virus that causes COVID-19.
We won't know how long immunity lasts after vaccination until we have more data on how well the COVID-19 vaccines work in real-world conditions. Experts are working to learn more about natural immunity and vaccine-induced immunity.
Viruses constantly change through mutation as part of their natural evolution, and new virus variants are expected to appear over time. Sometimes new variants emerge and then disappear. At other times, new variants emerge and persist. Various variants of the virus that causes COVID-19 have been documented worldwide during this pandemic.
The virus that causes COVID-19 is a type of coronavirus, a large family of viruses. Coronaviruses get this name because of the crown-shaped spikes found on their surface. These spikes are the structures through which the coronavirus that causes COVID-19 binds to cells to infect them. Scientists monitor changes in the virus, including changes in surface spikes. These studies, which include genetic analyzes of the virus, help scientists understand how changes in the virus can affect how it spreads and what happens to people who become infected with it.
There are different variants of the virus that causes COVID-19 in circulation in the world, the most important of which are the following:
- The United Kingdom (UK) identified a variant called B.1.1.7 with a large number of mutations in the fall of 2020.
This variant spreads more easily and quickly than the other variants. In January 2021, UK experts reported that this variant may be associated with an increased risk of death, relative to other variants of the virus, but further research is needed to confirm this finding. Since then, it has been detected in many countries around the world. The first case of this variant in the United States was detected in late December 2020.
- Another variant called B.1.351 appeared in South Africa, independently of B.1.1.7. B.1.35 was originally detected in October 2020, and shares some mutations with B.1.1.7. Cases caused by this variant were also reported in the United States in late January 2021.
- A variant called P.1 appeared in Brazil, which was first identified in travelers from Brazil undergoing routine screening tests at an airport in Japan in early January. This variant contains a set of additional mutations that could affect its ability to be recognized by antibodies. The first case of this variant in the United States was detected in late January 2021.
These variants appear to spread more easily and quickly than other variants, which could lead to more cases of COVID-19.
So far, studies suggest that antibodies generated through vaccination, with the currently authorized vaccines, recognize these variants. This aspect is being carefully studied and further research is ongoing.
Viruses constantly change through mutation as part of their natural evolution, and new virus variants are expected to appear over time. Sometimes new variants emerge and then disappear. At other times, new variants emerge and persist. Various variants of the virus that causes COVID-19 have been documented worldwide during this pandemic.
The virus that causes COVID-19 is a type of coronavirus, a large family of viruses. Coronaviruses get this name because of the crown-shaped spikes found on their surface. These spikes are the structures through which the coronavirus that causes COVID-19 binds to cells to infect them. Scientists monitor changes in the virus, including changes in surface spikes. These studies, which include genetic analyzes of the virus, help scientists understand how changes in the virus can affect how it spreads and what happens to people who become infected with it.
There are different variants of the virus that causes COVID-19 in circulation in the world, the most important of which are the following:
• The United Kingdom (UK) identified a variant called B.1.1.7 with a large number of mutations in fall 2020.
This variant spreads more easily and quickly than the other variants. In January 2021, UK experts reported that this variant may be associated with an increased risk of death, relative to other variants of the virus, but further research is needed to confirm this finding. Since then, it has been detected in many countries around the world. The first case of this variant in the United States was detected in late December 2020.• Another variant called B.1.351 appeared in South Africa, detected in October 2020, and shares some mutations with B.1.1.7. Cases caused by this variant were also reported in the United States in late January 2021. • A variant called P.1 appeared in Brazil and was first identified in travelers from Brazil undergoing routine screening in an airport in Japan in early January. This variant contains a set of additional mutations that could affect its ability to be recognized by antibodies. The first case of this variant in the United States was detected in late January 2021.
These variants appear to spread more easily and quickly than other variants, which could lead to more cases of COVID-19.
So far, studies suggest that antibodies generated through vaccination, with the currently authorized vaccines, recognize these variants. This aspect is being carefully studied and further research is ongoing.
