COVID-19 Vaccine Resources

COVID-19 Vaccine FAQs for the Construction Industry

COVID-19 vaccines are widely accessible in the United States. Everyone aged 5 years and older should get fully vaccinated against COVID-19 as soon as possible. The following list of frequently asked questions (FAQs) about COVID-19 vaccination was developed by The University of Texas Health Science Center at Tyler in coordination with the National Institute for Occupational Safety & Health (NIOSH) and CPWR – The Center for Construction Research & Training to help address questions that may come up among workers, employers, and others in the construction industry.

This page is updated regularly as new information becomes available. Last updated on December 2, 2021.

PDF versions of this resource are also available in both English and Spanish:
COVID-19 Vaccine FAQs for The Construction Industry (Version 6. 12-2-21)
Preguntas frecuentes sobre la vacuna contra la COVID-19 para la industria de la construcción (Versión 6. 2-12-21)


1. What is population immunity?

You may have heard health officials or reporters mention population immunity (also known as herd immunity) as a possible way to stop the spread of COVID-19. Population immunity occurs when enough of the population becomes immune to an infectious disease either from a previous infection or vaccination.  Once enough people are immune, it becomes unlikely a virus or bacteria can spread and cause disease.  Not every individual may be immune, but the community overall is protected because the virus dies out with nowhere to go. The percentage of people who need to have protection to achieve population immunity varies by disease. Experts do not know what percentage of people would need to get vaccinated to achieve population immunity to COVID-19, but the more people get vaccinated, the greater the chances that we will achieve population immunity.

2. What is the current vaccination rate in construction?

As of October 2021, just over 50% of those in construction occupations were vaccinated, compared to approximately 80% of those in all other occupations combined. To keep not only coworkers, but spouses, children, and other loved ones safe – especially from newer variants (see questions 4 and 5) – construction workers are strongly encouraged to get vaccinated.

3. How do the vaccines work?

COVID-19 vaccines are effective at protecting you from COVID-19, especially severe illness and death. COVID-19 vaccines reduce the risk of people spreading the virus that causes COVID-19.

Vaccines work with your body’s natural defenses so your body will be ready to fight the virus if you are exposed. These vaccines cannot give you the disease. There are currently two types of vaccines against COVID-19 authorized for use in the United States, messenger RNA vaccines and viral vector vaccines.

Messenger RNA vaccines—also called mRNA vaccines—are some of the first COVID-19 vaccines authorized for use in the United States (e.g., produced by Pfizer–BioNTech and Moderna). To trigger an immune response, many vaccines put a weakened or inactivated germ into our bodies. Not mRNA vaccines. 

Instead, COVID-19 mRNA vaccines ‘instruct’ our cells to make a harmless piece of the virus called the “spike protein.” Our immune system recognizes that the spike protein does not belong there and begins building an immune response and making antibodies, like what happens in natural infection against COVID-19. This immune response teaches our bodies how to protect against future COVID-19 infection. People who get COVID-19 from another person will gain protective immunity in the same way, but vaccines are much safer and offer better protection against future infection. For this reason, vaccination will still benefit people who have already been sick with COVID-19. The benefit of mRNA vaccines, like all vaccines, is that that they protect us from getting sick without having to actually get sick with COVID-19, which can be deadly.

Viral vector vaccines (e.g., produced by Johnson & Johnson/Janssen or J&J/Janssen) use a viral vector to deliver important instructions to our cells. The vector used in COVID-19 vaccines is not the virus that causes COVID-19. It is a modified version of a different, harmless virus. The vector enters a cell in our body and uses the cell’s machinery to produce a harmless piece of the virus that causes COVID-19.

Our immune system recognizes that this harmless piece of the virus, called a spike protein, does not belong there. This triggers our immune system to produce antibodies and activate other immune cells. At the end of the process, our bodies have learned how to protect us from getting sick with COVID-19. The benefit is that the vaccine protects us without the serious risk of getting sick with COVID-19. These vaccines cannot give us COVID-19 or other infections, and they do not affect or interact with our DNA.

4. What is the Delta variant?

Viruses are always changing, and that can cause a new variant, or strain, of a virus to form.  First detected in late 2020, the Delta variant causes significantly more infections and spreads faster than the original virus and other variants that cause COVID-19. Because of this transmissibility, it is now the dominant strain in the U.S., accounting for 99.9% of known cases.

The authorized COVID-19 vaccines are highly effective at preventing severe disease and death, including against the Delta variant (see question 6). However, they are not 100% effective at preventing infection altogether, and some fully vaccinated people will become infected (called a breakthrough infection – see below), causing them to experience illness and/or pass on the virus. For such people, the vaccine still provides them strong protection against serious illness and death.

5. What is the Omicron variant?

Omicron is a new form or variant of the virus that causes COVID-19. Viruses can change as they continue to spread. When not enough people are vaccinated, the virus spreads more easily and new variants like Omicron are more likely to emerge. Omicron has changes, called mutations, that might make it spread more easily or cause more severe disease. Research is underway to determine how this virus is different. This FAQ will be updated as we learn more.

6. Is the vaccine effective?

COVID-19 vaccines authorized for use in the United States (Pfizer-BioNTech, Moderna, and Johnson & Johnson/Janssen) are highly effective in preventing symptomatic COVID-19. Research suggests currently available vaccines have high effectiveness for preventing infection and hospitalization from the virus that causes COVID-19, including during periods of time with circulation of the Delta variant. Research to learn more about vaccine effectiveness against the Delta variant is ongoing.

In summary, benefits of receiving the vaccine significantly outweigh risks. People are encouraged to receive the earliest authorized vaccine available to them. For those receiving the mRNA vaccines (Pfizer-BioNTech or Moderna) it is important to get both doses to optimize protection.

The U.S. Occupational Safety and Health Administration (OSHA), in their “Guidance on Mitigating and Preventing the Spread of COVID-19 in the Workplace”, states that “vaccination is the key element in a multi-layered approach to protect workers.

7. What are breakthrough infections?

COVID-19 vaccines are highly effective at preventing serious infection, illness, and death.  However, since vaccines are not 100% effective at preventing infection, some people who are fully vaccinated will still get COVID-19. An infection of a fully vaccinated person is referred to as a “breakthrough infection”.

Fully vaccinated people with a breakthrough infection are less likely to develop serious illness than those who are unvaccinated and get COVID-19 — this means they are much less likely to be hospitalized or die than people who are not vaccinated. People who get breakthrough infections can be contagious.  CDC is collecting data on vaccine breakthrough infections and is monitoring the safety and effectiveness of all Food and Drug Administration (FDA)-authorized and approved COVID-19 vaccines.

8. What are the risks/side effects from receiving the vaccine?

Most people do not have serious problems after being vaccinated. Your arm may be sore, red, or warm to the touch. These symptoms usually go away on their own within a week. Some people report getting a headache or fever after getting a vaccine. These side effects are a sign that your immune system is doing exactly what it is supposed to do. It is working and building up protection to disease. 

While rare, more severe side effects such as anaphylactic reactions (“anaphylaxis” is a severe, potentially life-threatening allergic reaction that can occur very quickly) have been reported following vaccination with mRNA COVID-19 vaccines. Although investigations are ongoing, people with a history of an immediate allergic reaction (of any severity) to an mRNA COVID-19 vaccine or any of its components might be at greater risk for anaphylaxis upon re-exposure to either of the currently authorized mRNA COVID-19 vaccines. The recognized benefits of the vaccines outweigh the potential harms of becoming infected with COVID 19.

9. Are the vaccines safe?

10. After receiving the vaccine, how quickly am I protected?

11. How long does natural immunity last? How long will the vaccine protect me?

The protection someone gains from having an infection (called natural immunity) varies depending on the disease, and it varies from person to person. Since this virus is new, we do not know how long natural immunity might last, but available evidence shows that both fully vaccinated individuals and those previously infected each have a low risk of subsequent infection for at least 6 months. For information on booster shots, see questions 14-15 below.

12. If I have had a positive COVID test, do I need to receive the vaccine?

Yes, even if you’ve already had COVID, you should still get vaccinated. Research shows that unvaccinated individuals are more than twice as likely to be reinfected with COVID-19 than those who were fully vaccinated after initially contracting the virus. Anyone currently infected with COVID-19 should wait to get vaccinated until after they fully recover, and they are out of isolation/quarantine. In addition, if you were treated for COVID-19 symptoms with monoclonal antibodies or convalescent plasma, you should wait 90 days before getting a COVID-19 vaccine. Talk to your doctor if you are unsure what treatments you received. Current evidence suggests that reinfection is uncommon in the 90 days after initial infection. Therefore, people with a recent infection may delay vaccination until the end of that 90-day period if so desired.

13. How many doses do I need?

If you receive the Pfizer-BioNTech or Moderna COVID-19 vaccine, you will be given two doses. Those receiving the Johnson & Johnson COVID-19 vaccine will receive one dose.

The CDC also recommends that people with moderately to severely compromised immune systems receive an additional dose of mRNA COVID-19 vaccine at least 28 days after a second dose of Pfizer-BioNTech COVID-19 vaccine or Moderna COVID-19 vaccine. This is separate and different from the topic of booster shots (see question 14 below).

14. Should I get a booster shot?

A booster shot will help protect you against COVID-19 for a longer period of time. You should get the booster if you are 18 years or older and already vaccinated. You can get the booster at least two months after receiving the Johnson & Johnson shot initially or at least six months after completing your primary vaccination series with Pfizer-BioNTech or Moderna.

Those who work on construction jobsites, which often require multiple crew members working close together in small or unventilated spaces and may present difficulties adhering to preventive measures such as frequent hand washing and physical distancing, should get a booster.

15. Which booster shot should I get?

According to the CDC, any of the COVID-19 vaccines authorized in the United States can be used for the booster dose. Based on personal preference or local availability, you may choose to get the vaccine type you previously received or to get a different booster.

16. I've had my vaccine; can I stop wearing my mask (and other public health measures)?

If you are fully vaccinated, you can resume activities that you did before the pandemic. However, it is important to note:

It is still possible for you to contract the virus, although you may not notice any symptoms. To reduce the risk of being infected with COVID-19 and spreading it to others, wear a mask indoors in public if you are in an area of substantial or high transmission. You might choose to wear a mask regardless of the level of transmission if you or a family member have a weakened immune system or are at increased risk for another reason.

If you had close contact with someone who has COVID-19, you should get tested 5-7 days after your exposure, even if you don’t have symptoms. You should also wear a mask indoors in public for 14 days following exposure or until your test result is negative. You should isolate for 10 days if your test result is positive. These precautions help reduce your chance of being exposed to the virus or spreading it to others.

17. Is there a charge for the vaccine?

Vaccine doses purchased with U.S. taxpayer dollars will be given to the American people at no cost. However, vaccination providers can charge an administration fee for giving the shot to someone. Vaccine providers can get this fee reimbursed by the patient’s public or private insurance company or, for uninsured patients, by the Health Resources and Services Administration’s Provider Relief Fund.

18. I don't live in the city or in an urban setting, do I really need the vaccine?

Everyone aged 5 years and older should get fully vaccinated against COVID-19 as soon as possible. Initially, COVID-19 cases surged in crowded urban areas like New York City, but by July 2020, cases were surging in rural America as well. By the fall months of 2020, the number of cases per 100,000 residents in rural areas was greater than that of urban areas.