If you received the first dose of the Moderna or Pfizer vaccines, you are halfway to achieving protection against COVID-19. Full vaccine protection will only be achieved with the second dose. This is important because, the more people who complete their vaccinations, the closer we are to the end of the COVID-19 pandemic.

There are three vaccines available in Puerto Rico: Pfizer, Moderna, and Johnson & Johnson. The first two are mRNA vaccines and require a second dose to offer maximum protection. The J&J vaccine only requires one dose. Below we answer some questions about the vaccines and the protection they offer:

How do vaccines work? Are they safe?

The Pfizer and Moderna vaccines (mRNA vaccines) teach your immune system to recognize the presence of COVID-19 in your body and fight it.

Although the COVID-19 vaccine was developed in record time, it was created based on the research conducted to develop mRNA vaccines for other diseases, such as influenza, rabies, and Zika. In addition, the vaccine trial results have been extensively analyzed by experts in order to attest to its safety.

The J&J vaccine (viral vector type) contains a modified version of another virus that is not dangerous (the vector) to teach your body how to fight COVID-19.

When am I fully vaccinated?

Full vaccine protection is reached two weeks after the second dose of the Pfizer or Moderna vaccine. In the case of the J&J vaccine, it’s reached two weeks after the single dose.

Can I get COVID-19 from the vaccine?

No, the vaccines cannot infect you because they do not contain the COVID-19 virus.

Can I stop wearing a face mask if I get the vaccine?

No, you should continue wearing a face mask in public spaces for the moment. The CDC is starting to ease the use of face masks, however, stopping their use will depend on whether there are enough vaccinated people in Puerto Rico until we have reached the so-called herd immunity.

     Can the second dose be a different brand than the first?

No, the recommendation is that the second dose should be of the same brand as the first dose.

     I’m concerned about adverse reactions to the vaccine. Is it worth getting vaccinated?

Certainly, allergic reactions have happened. This is normal, but it is no reason to avoid getting the vaccine. However, these reactions are minor when compared to the protection the vaccine provides against an illness that has caused the death of several hundred thousand people in the United States and Puerto Rico. If you still have questions, talk to your doctor, who knows your medical history best.

     Why is the second dose so important?

The second dose is the one that truly increases the number of antibodies that neutralize the virus, and it is also the one that helps protect us against new variants of the virus.

Sources:

https://www.cdc.gov/coronavirus/2019-ncov/vaccines/different-vaccines/mrna.html

https://espanol.cdc.gov/coronavirus/2019-ncov/vaccines/expect.html

https://www.nytimes.com/2021/04/29/well/live/skipping-second-dose-coronavirus-vaccine.html .

https://www.cdc.gov/coronavirus/2019-ncov/vaccines/different-vaccines/viralvector.html