COVID-19 Vaccine & Booster Shot

COVID-19 Vaccine

Last updated: 4/19/2022

A COVID-19 vaccine, designed to prevent the COVID-19 disease, is the best hope for ending the pandemic. Holy Cross Health continues to encourage vaccination for all who are eligible and encourage everyone to speak with their doctor to make a personalized decision.

We know you may have many questions and concerns about the COVID-19 vaccines. That’s why Holy Cross Health is committed to keeping you informed and educated as major developments occur.

COVID-19 Vaccination Clinics

COVID-19 Vaccination Clinics


Holy Cross Health is hosting COVID-19 vaccination clinics throughout Montgomery County for adults and children. Register by phone or online. For additional clinics, visit the State of Maryland and Montgomery County websites.


Register Now

  Getting Vaccinated

The vaccine is now available for everyone six months and older. Visit and your state’s health department website for more information.

Think of a vaccine as a way for your immune system to practice for an infection. Vaccines give the body a preview of a virus or bacteria before you get the real deal. The immune system then learns and remembers how to react. This helps the body stop the virus or bacteria from making you sick if you are exposed to it.

The vaccines authorized are highly effective at preventing severe disease, death, and provide protection from the Delta variant. The vaccines are not 100 percent effective and some fully vaccinated people may experience illness. It’s important that as many people as possible get vaccinated to slow the spread of variants.

Delta Variant: What We Know About the Science | CDC

The vaccines authorized are highly effective at preventing severe disease, death, and provide protection from the Omicron variant. The vaccines are not 100% effective, and some fully vaccinated people may experience illness. It’s important that as many people as possible get vaccinated to slow the spread of variants. Newer versions of the vaccine may be available in fall 2022 that will provide even better protection against the newer variants of COVID-19.

Omicron Variant: What You Need to Know

We are confident the COVID-19 vaccines are safe and effective with the FDA’s emergency use authorizations and now permanent approval of the Pfizer vaccine. The vaccines passed numerous, required safety checks, and study of reported side effects or adverse events. Several months of data have shown us that vaccines are safe and effective.

We encourage you to visit the State of Maryland and Montgomery County websites for the most up-to-date information or find the vaccine at a local pharmacy in your area. 

All persons ages six months and older are now eligible to receive the vaccine. Visit and your state’s health department website for more information.

The COVID-19 vaccine gives your immune system a preview of the coronavirus, so it learns how to stop it. It triggers antibodies in your blood to attack the virus’s unique spike protein. (Did you know, coronaviruses got their name because they have protein spikes that look like a crown?)

Your immune system learns from the vaccine how to quickly recognize the actual virus and stop it from multiplying. The idea is to stop SARS-CoV-2, the virus that causes COVID-19, from getting into cells, replicating itself and making you sick.

Two doses of the Pfizer or Moderna vaccines are needed to provide the complete protection. The first one primes the immune system, helping it to recognize the virus, and the second one strengthens the immune response. If the vaccine you received requires two doses, you should receive both doses. You should also stay up to date on your COVID vaccines by receiving any recommended booster doses.

The single-dose Johnson and Johnson vaccine is also considered in some situations such as for people who are allergic to an ingredient in the Pfizer or Moderna vaccines.

No. None of the COVID-19 vaccines are made with a live virus. They cannot give you COVID-19.

Due to the severe health risks associated with COVID-19 and the fact that re-infection with COVID-19 is possible, it is recommended everyone eligible get a COVID-19 vaccine-even if they have been sick with COVID-19 before. At this time, experts do not know how long someone is protected from getting sick again after recovering from COVID-19. The immunity someone gains from having an infection, called natural immunity, varies from person to person. Some early evidence suggests natural immunity may not last very long.

Yes, the vaccination is recommended for all people six months and older, including people who are trying to get pregnant, are pregnant, breastfeeding, or may become pregnant in the future. Data from thousands of people who are pregnant, breast-feeding and those who became pregnant after vaccination confirms that the COVID-19 vaccine is safe and effective before, during and after pregnancy.

In fact, the CDC has issued a health alert recommending those who are pregnant, recently given birth, are breastfeeding, or trying to become pregnant receive a COVID-19 vaccine as soon as possible.

The CDC V-Safe data shows no increase in adverse outcomes in pregnant women who receive the COVID-19 vaccine. There is also no evidence linking vaccines to infertility. The risks of COVID-19 infection outweigh any known or potential risks of vaccination while pregnant or trying to conceive.

Pregnant women are at a higher risk to get ill with COVID-19 compared with non-pregnant women. A study was conducted before the Delta variant; results published by the Journal of the American Medicine Association showed pregnant women with COVID infection are 15 times more likely to die in hospital, 14 times more likely to require intubation, and 22 times more likely to have a premature birth.

See the CDC’s COVID-19 Vaccines While Pregnant or Breastfeeding info page.

Having a weakened immune system can make you more likely to get severely ill from COVID-19. The CDC recommends after completing the primary series, some moderately or severely immunocompromised people should get an additional primary shot, followed by a booster. See the CDC website for detailed information about what to receive and when: COVID-19 Vaccines for Moderately or Severely Immunocompromised People | CDC.

According to the CDC, those who are fully vaccinated will continue to be protected against serious illness and hospitalization. However, some study data suggests that immunity may decline over time after the primary series. Booster doses are recommended for optimal protection against the virus.

In November 2021, the FDA authorized a booster dose of the Pfizer-BioNTech COVID-19 vaccine and the Moderna COVID-19 vaccine for millions of Americans to be administered at least five months after their second dose of the Pfizer vaccine. Individuals who completed the Johnson & Johnson primary vaccine series should receive a booster at least two months after their initial vaccination.

The CDC recommends booster doses of the COVID-19 vaccine for those who are moderately or severely immunocompromised, with the number of booster doses dependent on age. Immunocompromised individuals aged 12 and older should receive a total of 5 doses of mRNA vaccine to be considered up to date. A complete schedule of COVID-19 booster doses for immunocompromised individuals is available on the CDC website:

The CDC recommends that everyone 5 years and older get their primary series of COVID-19 vaccines, and receive a booster dose when eligible. A booster dose provides additional protection against the virus. See the CDC’s website for detailed information on staying up to date with your vaccines: Stay Up to Date with Your Vaccines | CDC.

Boosters for adults 18 years and older should be given as follows:

  • Pfizer/Moderna: 6 months after the first series
  • Johnson & Johnson: 2 months after initial vaccination

Visit the State of Maryland and Montgomery County websites for the most up-to-date information or find the vaccine at a local pharmacy in your area.

Yes. People who are immunocompromised are more likely to be hospitalized and get seriously ill from COVID-19. It’s recommended you get vaccinated if you are immunocompromised. These people may not get as much protection after two doses of the vaccine as do people with normal immune systems. For that reason, additional doses are now recommended, with the schedule varying by primary vaccine series.

If you are immunocompromised, discuss the vaccine with your doctor for a personalized recommendation. In addition, discuss with your doctor whether you should get a medication called Evusheld that will help provide additional protection against COVID-19.

In clinical trials, Novavax was 90% effective against mild, moderate, and severe COVID-19 infection.

Novavax uses a more traditional method of generating an immune response than the other COVID-19 vaccines. The vaccine includes a protein from the virus itself to strengthen the immune response. This vaccine technology is like that used in flu or Hepatitis B vaccines.

 The Pfizer-BioNTech and Moderna vaccines rely on newer mRNA technology. These vaccines deliver a set of instructions to cells, which then create pieces of COVID-19’s spike protein and generate corresponding antibodies.

  Children and Vaccines

Recently, Pfizer and BioNTech submitted their application to the FDA for emergency use authorization of their COVID-19 vaccine for children 6 months through 4 years old. The FDA is reviewing the information. If authorization is granted, it would be the first COVID-19 vaccine available for children under 5 years old.

Yes, COVID-19 vaccines approved for emergency use authorization (EUA) in the United States are safe. The vaccines go through the same testing and clinical trials as all vaccines and no serious safety concerns have been identified.

Authorized For Pfizer-BioNTech Moderna J&J / Janssen
4 years and under No No No
5–11 years old Yes No No
12–17 years old Yes No No
18 years and older Yes Yes Yes

While most children are at lower risk for severe illness from COVID-19, there are still many unknown long-term effects. While uncommon, it is also possible for children infected with COVID-19 to become seriously ill or worse. Vaccination also allows for a safer return to activities and normal life. Vaccination will

  • Lower the risk of serious illness including Multisystem Inflammatory Syndrome in Children (MIS-C)
  • Eliminate the need to quarantine if your child is exposed to COVID-19 at school or elsewhere
  • Keep your child from missing sporting events or extracurricular activities after exposure
  • Lower the risk of long-term effects of COVID-19
  • Lower the risk of passing COVID-19 infection to family members and others at high-risk for severe illness from COVID-19

Clinical trials show COVID-19 vaccines are very effective in children. In fact, data shows the immune response for children ages 12 to 15 was better than trial participants ages 16-25, with no COVID cases in the vaccinated group.

Trials for younger children took place during the Omicron waves, which lowered the vaccine’s effectiveness. However, the vaccines were still protective, generating similar antibody levels as vaccines for older age groups.

Side effects in children are similar to those in other age groups. The most common side effects include:

  • Pain at the injection site
  • Fatigue (feeling tired)
  • Headache

Side effects are generally mild and resolve quickly. Long-term side effects are unlikely, as clinical studies demonstrated safety for multiple months past the typical timeframe for vaccine reactions.

For the Pfizer vaccine, 12- to 15-year-olds will receive the same dosing as adults. Clinical trials tested the adult dose and two smaller doses to determine safety and efficacy. This dose was proven safe and shown to be most effective for this age group. Children aged five to 11 years receive a smaller dose as part of a two-dose series, and children six months to 4 years receive an even smaller dose in a three-dose series.

For Moderna, children aged six months to 5 years receive one-quarter the adult dose in a two-dose series. Children aged six to 11 years receive half the adult dose, and children 12 to 17 years old receive the full adult dose, both as a two-dose series.

There is no clinical evidence to suggest COVID vaccines have effects on puberty or fertility.

It will be up to each state's government to decide whether a COVID-19 vaccine is required for school entry. Many colleges and universities require students to be vaccinated against COVID-19.

  • Completed clinical trials with children including a follow-up period of at least two months
  • Manufacturers analyze clinical trial data to evaluate the safety and effectiveness of the vaccine. The FDA works closely with manufacturers to ensure data analysis meets regulatory standards.
  • After a full evaluation, manufacturers request an emergency use authorization (EUA) or submit for permanent approval through a biologics license application (BLA).
  • The FDA evaluates the data in an independent review evaluating the benefits and risks.
  • The FDA approves or denies the EUA or BLA request based on its findings.

Data from the full clinical trials are reviewed by multidisciplinary experts following submission by vaccine manufacturers. The CDC and the FDA now recommend children 5 to 11 years old be vaccinated against COVID-19 with the Pfizer-BioNTech pediatric vaccine.

Parents or guardians should consult with their child’s pediatrician to determine the appropriate time to vaccinate their child.

The best way is for all adults and eligible children around them to get vaccinated. Children should also wear masks as recommended and follow other precautions until they can receive the vaccination.

There is no clinical evidence to suggest COVID-19 vaccines have effects on puberty or fertility.

The COVID-19 vaccines will not affect puberty, growth, or fertility since they can’t alter cells. After mRNA vaccine instructs our body starts to make antibodies to fight COVID, the enzymes in our bodies chop up the mRNA into pieces, and it’s gone within days!

It’s mostly fat, salt, electrolytes and sugar. Lipids, such as polyethylene glycol (PEG), are the "fatty layer" that protects the delicate mRNA so it has time to work before getting chopped up.

 Potassium chloride, monobasic potassium phosphate, sodium chloride and dibasic sodium phosphate dihydrate and sucrose are just fancy names for some salts and sugar. These ingredients help keep the vaccine stable and are natural preservatives.

Yes. The natural immunity produced by the body after a COVID-19 infection isn’t as strong as immunity produced by the vaccine. The vaccine gives protection and prevents hospitalization for several of the COVID variants.

Billions of doses of the COVID-19 vaccine have been given worldwide. The COVID-19 vaccine is no longer "new." Scientists and pediatricians feel confident in the safety of the COVID-19 vaccine and the booster. Waiting puts children at higher risk for infection and illness. The vaccine and booster got to us fast because: 

  • The vaccine research for mRNA started in 1961 and, in the last decade specifically, was focused on SARS.
  • The vaccine was released more quickly than other vaccines because the production started before the clinical trials. This was due to the pandemic, which provided funding and resources to make that happen.  

Since it has been given to so many with very few complications over a year now, there is a lot of confidence in the safety of the COVID vaccine. We now know that COVID complications from the disease can be MUCH worse than complications we have seen with the vaccine.

As of June 2022, over 13 million COVID-19 pediatric cases have been reported in the U.S. The CDC estimates 209,254 pediatric hospitalizations in the U.S. As of June 2022, there have been 8,525 cases of MIS-C, a serious health condition affecting multiple organs that has been linked to COVID-19 infection.

Over 1,200 pediatric deaths* have been reported since the beginning of the pandemic in the U.S. Although this seems low compared to adults, COVID is now one of the top 10 causes of death for adolescents in the United States.

Data from:

Long COVID has also been reported among kids. The U.K Office for National Statistics is reporting that roughly 12-14% of kids experience long-term side effects of COVID.

The Omicron variant has changed the game. It is three times more transmissible than the Delta variant and spreads much more quickly.

More quarantine, worsening mental health and school concerns: Those children and teens without the vaccine will likely face more quarantines and more isolation from school, sports, and other activities. This can lead to increased mental health concerns.

Myocarditis is an extremely rare side effect of the mRNA vaccine, affecting about 26 cases of per one million doses given. That's a 0.0026% risk.. Most cases are mild, and teens often recover on their own or with minimal treatment like ibuprofen (Advil/Motrin). In addition, we know that myocarditis is much more common if you get COVID or even the flu, and the risks of heart disease from COVID infection can be more severe and long lasting.

  After Vaccination

The vaccine requires two doses three or four weeks apart, depending upon vaccine. Immunity takes some time to develop- at least two weeks after last the last injection. For example, someone vaccinated in late December won’t be fully protected until late January or early February. To be considered up to date on COVID vaccines, people should receive all recommended boosters.

Side effects are like other vaccines. The most common side effects are pain/redness at the injection site, headache, fatigue, muscle/joint aches, and low-grade fever. The side effects respond well to Tylenol and ibuprofen. Most side effects last less than 24 hours and those ages 55 and older reporter fewer side effects.

According to the CDC, fully vaccinated people can:

  • Visit with other fully vaccinated people indoors without wearing masks or physical distancing
  • Visit with unvaccinated people (including children) from a single household who are at low risk for severe COVID-19 disease indoors without wearing masks or physical distancing
  • Participate in outdoor activities and recreation without a mask, except in certain crowded settings and venues
  • Resume domestic travel and refrain from testing before or after travel or self-quarantine after travel
  • Refrain from testing before leaving the United States for international travel (unless required by the destination) and refrain from self-quarantine after arriving back in the United States
  • Refrain from testing following a known exposure, if asymptomatic, with some exceptions for specific settings
  • Refrain from quarantine following a known exposure if asymptomatic
  • Refrain from routine screening testing if asymptomatic and feasible
  • Take precautions in indoor public settings like wearing a well-fitted mask
  • Wear well-fitted masks when visiting indoors with unvaccinated people who are at increased risk for severe COVID-19 disease or who have an unvaccinated household member who is at increased risk for severe COVID-19 disease
  • Wear well-fitted masks when visiting indoors with unvaccinated people from multiple households
  • Avoid indoor large-sized in-person gatherings
  • Get tested if experiencing COVID-19 symptoms
  • Follow guidance issued by individual employers
  • Follow CDC and health department travel requirements and recommendations

Although the risk that fully vaccinated people could become infected with COVID-19 is low, any fully vaccinated person who experiences symptoms consistent with COVID- 19 should isolate themselves from others, be clinically evaluated for COVID-19, and tested for COVID-19, if indicated. The symptomatic fully vaccinated person should inform their healthcare provider of their vaccination status at the time of care.

You can obtain a copy of your COVID-19 vaccination record by visiting, Maryland’s vaccination consumer portal. The site will match you to your record in the state immunization database (ImmuNet). Then, you can print/save a PDF copy of your record.

Safety and Development

For information about the safety and development of the COVID-19 vaccines, please visit the Centers for Disease Control and Prevention website.