Vaccine FAQs

Where can I find information on how my state is prioritizing vaccinations, and when it will be my turn?

Since the start of the COVID-19 pandemic, states have had the ultimate say in most COVID-19-related rulemaking and recommendations (e.g. including stay-at-home orders, mask-wearing, business limitations, and essential worker distinctions). Directives for the roll-out of virus vaccines are no different. As explained by the National Governors Association (NGA), it is each state’s individual responsibility to “manag[e] the systems for ordering, distributing, and monitoring vaccines” – i.e., determine where your workers fall in the system’s priority of distribution.

However, it is not easy to find current information specific to each state. So, to assist our clients and readers, TAG scoured the web for resources, ready to develop our own, if needed. Following are three sources we found, through which current information can be attained:

  • National Governors Association (NGA). has a comprehensive and regularly updated list, as its State COVID-19 Vaccine Resources webpage links to the vaccine public health webpage of every state and U.S. territory. While declared as being “not exhaustive of statewide actions,” it is as up to date on vaccine information as has been published by each state and territory.
  • CDC. The CDC’s Vaccine page includes a section titled “See how and when you can get vaccinated.” Selecting your state or territory from the dropdown list links to the health department webpage to explain how it determines how vaccines are distributed.
  • Kaiser Family Foundation (KFF). In its “State Vaccine Resources” webpage, KFF discuss the state responsibility for vaccines, then includes a listing of states and territories with links to their vaccine pages.

While some of these links are repetitive, we’ve included them all to ensure you are able to find the most current information available.

FDA has issued, or is considering, Emergency Use Authorization (EUA) for some COVID-19 vaccines. What exactly is an EUA? What is required for FDA’s issuance of an EUA?

Under section 564 of the Federal Food, Drug, and Cosmetic Act (FD&C Act), the Emergency Use Authorization (EUA) gives the FDA Commissioner authority to allow unapproved medical products or unapproved uses of approved medical products to be used in an emergency to diagnose, treat, or prevent serious or life-threatening diseases or conditions caused by (Chemical, Biological, Radiological or Nuclear (CBRN) threat agents when there are no adequate, approved, and available alternatives. Thus FDA may issue an EAU if:

• CBRN agent referred to in the March 27, 2020 EUA declaration by the Secretary of HHS (SARS-CoV-2) can cause a serious or life-threatening disease or condition.

• Based on the totality of scientific evidence available, including data from adequate and well-controlled trials, if available, it is reasonable to believe that the product may be effective to prevent, diagnose, or treat such serious or life-threatening disease or condition that can be caused by SARS-CoV-2, or to mitigate a serious or life-threatening disease or condition caused by an FDA-regulated product used to diagnose, treat, or prevent a disease or condition caused by SARS-CoV-2.

• The known and potential benefits of the product, when used to diagnose, prevent, or treat the identified serious or life-threatening disease or condition, outweigh the known and potential risks of the product.

• There is no adequate, approved, and available alternative to the product for diagnosing, preventing, or treating the disease or condition. If these criteria are met, under an EUA, FDA can allow unapproved medical products (or unapproved uses of approved medical products) to be used in an emergency to diagnose, treat, or prevent serious or life-threatening diseases or conditions caused by threat agents.

Does the vaccine prevent COVID or does it just reduce the symptoms to prevent hospitalization? Could I take just one dose of the Pfizer or Moderna (two-dose) vaccines?

Like the vaccine for the flu, the COVID vaccine significantly reduces your chances of being infected. Like the flu vaccine, if you do become infected, the COVID vaccine reduces the severity of the illness.

Although the vaccines do provide some protection after the first dose, their efficacy is greatly increased with the second dose. According to the peer-reviewed results of a phase III trial, efficacy of the Pfizer between the first and second doses was 52%, but the second dose increased that efficacy to 95% a week after it being received.

What do the percentages cited for vaccine efficacy really mean?

There has been a lot of discussion lately about vaccine efficacy and the reported differences between the Pfizer and Moderna vaccines and that of Johnson & Johnson/Janssen (J&J). But the lower reported efficacy of the J&J vaccine does not mean it is worse or that the Pfizer and Moderna vaccines are better. Here’s why.

  1. Vaccine efficacy measures the ability of a vaccine to lower the risk of a negative outcome. When a vaccine’s efficacy percentage is reported, that percentage does not mean the number of people who will (or won’t) contract an illness; instead vaccine efficacy/effectiveness is interpreted as the proportionate reduction in disease among the vaccinated group. But it does measure the “percent reduction in disease incidence.”
  2. A direct comparison of efficacy among these vaccines isn’t possible. The Pfizer, Moderna, and J&J clinical trials were conducted at different times, in different places, and defined efficacy looking at different “endpoints” or definitions of symptomatic or severe COVID-19 infection – making direct comparison of the three impossible. Future research trials, designed to compare standardized efficacy among vaccines, could tell us which vaccines are more effective than others.
  3. All three are highly effective at preventing severe illness and death.  Given that we’re still in a global pandemic, the most important thing to know is that all three of these vaccines are highly effective (between 80-90%) at preventing hospitalizations and almost 100% effective in preventing death from COVID-19.  This highly significant reduction in severe illness is what will help end the pandemic and get life back to normal.
  4. Each of the currently available COVID-19 vaccines was developed to be effective against the predominant strains at the time of their initial development. However, with the evolution of various strains, this impacts the efficacy of each of the different vaccines. Despite that, with the vaccines, one’s body can/will react against the virus and build an immune response to much better able to protect you!

I’ve read that the cold-chain temperature requirements of vaccines that are closest to roll-out limit that amount of time that they are “fresh” – and that two doses will be required. Can you provide more information on this?

There are three vaccines that have undergone late-stage clinical trials [link to Vaccines 101] and are closest to or have received FDA authorization. Following are the dosage and temperature requirements for these:

·     Pfizer. The two-dose vaccine to be received about 21 days apart received a recommendation for FDA EUA approval from its vaccine advisory committee on December 10. The biggest challenge will be storage and distribution: Due to the low-temperature storage conditions (-94), Pfizer has developed temperature-controlled thermal shippers utilizing dry ice to maintain recommended temperature conditions of -70°C±10°C for up to 10 days. If the vaccine is stored in refrigerated (2 – 8°C) conditions, it can be stored for up 5 days. Once thawed and stored under 2 – 8°C conditions, the vials cannot be re-frozen. Read Pfizer’s plan. Once in the refrigerator, the vaccine must be used within 5 days.

·     Moderna. Two-dose vaccine – people will need to receive two doses about 28 days apart. The biggest challenge will be storage and distribution: Vaccine can be shipped at -20C (-4F) and stored for up to 6 months at that temperature. However, once thawed and in the refrigerator (2 – 8°C), the vaccine can be stored for up to 30 days. (Under FDA EUA consideration in December 2020.)

·     AstraZeneca & Oxford University. Two-dose vaccine – people will need to receive two doses. Storage: The AstraZeneca vaccine can be transported and stored at refrigerator temperatures (2 – 8° C), which makes this vaccine much more accessible than the others.

For more information, visit TAG’s overview and Vaccine 101 paper (pdf).

Since we are in a critical infrastructure business, I’ve heard talk that our access to the vaccine is right around the corner. What do you see as realistic timing /expectations – recognizing that this is a fluid situation?

This is a fluid situation, and it is one in which the states will be making the priority determinations. But the expectation is that most states are likely to follow the recommendations that were made by the CDC Advisory Committee on Immunization Practices (ACIP) in a November meeting —  a phased-in process, prioritizing healthcare workers and long-term care facility residents. The first phase of the ACIP proposal then includes vaccination essential workers followed by adults with igh-risk medical conditions and those over 65.

Is it safe for pregnant women, nursing women, and women who plan to become pregnant to receive a Covid-19 vaccine?

CDC has stated that those who are pregnant can choose to be vaccinated when it's available to them, as “there is currently no evidence that antibodies formed from COVID-19 vaccination cause any problem with pregnancy, including the development of the placenta.” Additionally, those who are trying to become pregnant now or who plan to try in the future also may receive the COVID-19 vaccine, as there is no evidence that fertility problems are a side effect of any vaccine, including those for COVID-19.  CDC also states that “Observational data demonstrate that while the absolute risk is low, pregnant people with COVID-19 have an increased risk of severe illness, including illness resulting in ICU admission, mechanical ventilation, or death. Additionally, they might be at an increased risk of adverse pregnancy outcomes, such as preterm birth.”

Those who are breastfeeding also can choose to be vaccinated, as the vaccines are not thought to be a risk to breastfeeding infants. However, there are no data on either the safety of COVID-19 vaccines in lactating women or on the effects of mRNA vaccines on the breastfed infant or on milk production/excretion.

Vaccine manufacturers are continuing to study this. Pfizer has submitted plans for a clinical study to assess safety and immunogenicity in pregnant women and proposed active surveillance studies designed to monitor vaccination during pregnancy within populations expected to receive the vaccine under EUA.

In making the decision, CDC recommends that you consider the level of COVID-19 community transmission, your risk of contracting COVID-19, the risks of COVID-19 to you and potential risks to the fetus, the efficacy of the vaccine, the side effects of the vaccine and the lack of data about the vaccine during pregnancy.

If a person who has received the COVID-19 vaccine begins showing symptoms of the virus, should they be allowed to work, under the assumption that the symptoms are simply a reaction to the vaccine? Or should they be excluded?

If a person who has been vaccinated shows symptoms, TAG recommends that they be excluded from work. There is overlap between post-vaccination symptoms and those of the virus, so the two cannot be differentiated. It also is possible that the person could have been infected just prior to being vaccinated, so would have the virus and be infectious to others.

TAG recommends that any symptomatic persons be tested, as only the virus itself, not the vaccine, would cause a positive result. As stated by CDC, “Vaccines currently in clinical trials in the United States won’t cause you to test positive on viral tests, which are used to see if you have a current infection.” However, this is not true of antibody tests (which indicate you had a previous infection), as the immunities developed in the body through the vaccine may result in a positive.

The most common reaction to the Pfizer vaccine has been injection site reactions (84.1%), with other generally mild to moderate symptoms including: were fatigue (62.9%), headache (55.1%), muscle pain (38.3%), chills (31.9%), joint pain (23.6%), fever (14.2%). Severe adverse reactions occurred in 0.0% to 4.6% of participants, were more frequent after Dose 2 than after Dose 1, and were generally less frequent in adults ≥55 years of age (≤2.8%) as compared to younger participants (≤4.6%).

Among adverse events of particular interest, which could be possibly related to the vaccine, lymphadenopathy was reported in 64 participants (0.3%): 54 (0.5%) in the younger (16 to 55 years) age group; 10 (0.1%) in the older (>55 years) age group; and 6 in the placebo group. The average duration of these events was approximately 10 days, with 11 events ongoing at the time of the data cutoff.

Has CDC published any further guidance on prioritization of the COVID-19 vaccine distribution?

On Sunday, December 20, CDC’s Advisory Committee on Immunization Practices (ACIP) updated its vaccine guidance to further define priority groups. Following healthcare workers currently being vaccinated, ACIP recommends that frontline essential workers and people ages 75 and older be next in line as Phase 1B. 

  • Frontline essential workers are defined as firefighters, police officers and workers in education, food and agriculture, manufacturing, corrections, the U.S. Postal Service, public transit and grocery stores. This phase consists of about 49 million people.
  • Following that, Phase 1c is recommended as including additional essential workers as those in transportation, food service, shelter/housing (construction), finance, information technology, energy, media, legal, public safety (engineers) and water/wastewater industries.

Interestingly, ACIP divided food workers — putting food and ag, manufacturing and grocery in Phase 1B and foodservice into 1c. So this is an area of which the industry should be aware.

If the CDC director accepts ACIP’s recommendation, the CDC will provide more guidance on how to implement each phase.  Ultimately, individual states will determine their prioritization strategies for vaccine distribution although many will follow CDC’s guidance.

Why do I need to continue to wear a mask after receiving that COVID-19 vaccine?

 It is important to continue to wear a mask and continue all other COVID protections because, at this stage we don’t know if the vaccine will prevent transmission of the virus. That is, if you get exposed to COVID-19 after being vaccinated, you may still be able to be infected, though probably asymptomatically and for a short period, thus, you may still be able to transmit it to others. You also could have been infected before you were vaccinated, which would make it possible to transmit the virus to others.

Also, CDC states that experts need to learn more about the protection that COVID-19 vaccines provide under real-life conditions before deciding to change recommendations on steps everyone should take to slow the spread of the virus that causes COVID-19. “There is not enough information currently available to say if or when CDC will stop recommending that people wear masks and avoid close contact with others to help prevent the spread of the virus that causes COVID-19.”

I was diagnosed with COVID. Can – and should – I still be vaccinated?

With no studies having indicated that a person who has had COVID should not be vaccinated, and no definitive knowledge of if, or how long, immunity may be conferred by having had the virus, the recommendation is that those who had the virus should be vaccinated.

According to the December 13 CDC MMWR (Pfizer) and  December 20 CDC MMWR (Moderna): “No specific safety concerns were identified in subgroup analyses by age, race, ethnicity, underlying medical conditions, or previous SARS-CoV-2 infection.” Additionally, a detailed summary of safety data, including information on reactogenicity, also is available at CDC.

When will we begin to see results of the vaccination having an impact our ability to return to a “normal” mask-less, non-distancing lifestyle?

At this stage we just don’t know but would expect that it will be at least another 6-9 months based on what we do know about COVID-19 and viruses in general.

It will depend on a number of factors, including the efficacy of the vaccine given in the greater numbers; how much immunity the vaccine provides and how long it lasts; and how quickly we’ll be able to get to a level of vaccination and immunity that significantly reduces the rate of spread – about 70-80%.

With some people having viral symptoms following a COVID-19 vaccination, how do we know if the person has the virus or is reacting to the vaccine? And when should they return to work?

Because we cannot differentiate between a vaccine reaction and the actual disease, TAG recommends that businesses take a cautious approach, assuming the symptoms are COVID based, for the protection of other employees and the business as a whole. That is:

  • Any employee who has symptoms associated with COVID-19 should stay home for 10 days following system onset even if the employee was recently vaccinated and suspects that the symptoms are due to the vaccine.
  • If symptoms following a vaccination resolve sooner without the aid of medication, the employee can return to work sooner if a COVID-19 PCR test is taken and returns negative.
  • Other employees who experience COVID-19 symptoms but were not recently vaccinated may return to work when symptoms have resolved for 24 hours if it is at least 10 days post symptom onset or they have a negative test/medical assessment.

Additionally, because there may be some operational impact if a high percentage of your employees would have post-vaccination symptoms, TAG recommends that employee vaccinations be staggered as much as possible.

The country overall is doing very well in reducing cases, but we are not out of woods when it comes to the variants – and, given that community case rates are still relatively high in many parts of the US, bringing back symptomatic people who may, indeed, have the virus can increase the risk of workplace transmission. As vaccination rates continue to increase, we expect to see a slow and steady reduction in the national case rate.  Right now, we are in a period of this pandemic where more infectious variants are becoming the predominant strains while vaccination rates (and some natural immunity from previous infections) are increasing.  We are closely watching for rapid surges in cases over the next month that could signal the impact of these new (B.1.17, B.1.153, P.1, and others) emerging variants.

If the vaccines include no part of the actual live virus, why do they cause COVID-like symptoms/side effects? Does the vaccine modify our RNA?

The Pfizer and Moderna vaccines are messenger RNA (mRNA) vaccines; neither contain the live virus that causes COVID-19 and, therefore, cannot give you COVID-19. Instead, they teach our cells how to make a protein—or a piece of a protein—that triggers an immune response inside our bodies. That immune response, which produces antibodies, is what protects us from getting infected if the real virus enters our bodies. But it also is what can cause side effects of COVID-like symptoms as our bodies adapt.

To build immunity,

  • COVID-19 mRNA vaccines give our cells instructions to make a harmless piece of the “spike protein” found on the surface of the virus that causes COVID-19. Once the instructions (mRNA) are inside the immune cells, the cells use them to make the protein piece. After the protein piece is made, the cell breaks down the instructions and gets rid of them.
  • Next, the cell displays the protein piece on its surface. Our immune systems recognize that the protein doesn’t belong there and begins building an immune response and making antibodies, like what happens in natural infection against COVID-19.

The Johnson & Johnson (Janssen) vaccine is a viral vector vaccine. As explained by CDC,

  • Viral vector vaccines use a modified version of a different virus (the vector) to deliver instructions to our cells. For COVID-19 viral vector vaccines, the vector (not the virus that causes COVID-19, but a different, harmless virus) will enter a cell in our body and then use the cell’s machinery to produce a harmless spike protein of the virus that causes COVID-19.
  • The cell displays the spike protein on its surface, and our immune system recognizes it doesn’t belong there. This triggers our immune system to begin producing antibodies and activating other immune cells to fight off what it thinks is an infection.

At the end of both processes, our bodies have learned how to protect us against future infection with the virus that causes COVID-19. Any temporary discomfort experienced after getting the vaccine is a natural part of the process and an indication that the vaccine is working. So, by getting vaccinated, your body gains long-lasting protection without you having to risk the serious consequences of getting sick with COVID-19.

Does an employee who has been vaccinated need to quarantine if they are exposed to a person with COVID-19?

According to CDC’s new guidance of February 10, with which TAG agrees:

Vaccinated persons with an exposure to someone with suspected or confirmed COVID-19 are not required to quarantine if they meet all of the following criteria:

  • Are fully vaccinated:
    – ≥2 weeks following receipt of the second dose in a two-dose series
    – ≥2 weeks following receipt of one dose of a single-dose vaccine
  • Are within 3 months following receipt of the last dose in the series. (This is due to the newness of the vaccines and the studies still being conducted on long-term efficacy.)
  • Have remained asymptomatic since the current COVID-19 exposure. If the person does have symptoms, follow the TAG recommendations discussed here.

Should someone who has been vaccinated, still be tested for COVID-19 if they are symptomatic or part of regular surveillance testing programs?

Yes – according to the same CDC guidance: “At this time, vaccinated persons should continue to follow current guidance to protect themselves and others, including wearing a mask, staying at least 6 feet away from others, avoiding crowds, avoiding poorly ventilated spaces, covering coughs and sneezes, washing hands often, following CDC travel guidance, and following any applicable workplace or school guidance, including guidance related to personal protective equipment use or SARS-CoV-2 testing.”

TAG agrees with this guidance because vaccines are not 100% effective and therefore testing someone for active infection remains a key strategy to reduce the risk of transmission.  It’s also important to stress that the currently authorized mRNA vaccines are extremely effective at preventing moderate to severe illness and should significantly reduce the likelihood that someone would test positive for an active infection after they’ve been vaccinated. 


What is the transmission rate of school age kids versus adults? Is it being spread through the schools?

Although fewer children than adults have become sick with COVID-19, children can be infected, get sick, and also transmit the virus. Like adults, they can be asymptomatic and spread the virus to others. Most children infected with COVID-19 have had mild or no symptoms. However, some have gotten severely ill (or died) from COVID-19, requiring hospitalization, intensive care, or a ventilator to help them breathe. CDC is currently investigating a rare but serious medical condition associated with COVID-19 in children called Multisystem Inflammatory Syndrome in Children (MIS-C). Both the cause of MIS-C and who is at increased risk for developing it is still unknown. [CDC]

When do we expect children to be able to get the vaccine to help slow the spread as well?

For things to return to some sort of normalcy, children, as well as adults, will need to be vaccinated. However, as the Cleveland Clinic explains, since childrens’ immune systems can vary greatly depending on age, clinical trials for children often include more layers of protection. A 16 year old will have a much different immune system than a 16 month old. Because of this, additional data and research is needed when evaluating a vaccine for kids.  Because of the differences with their immune systems and the protection and safety protocols in clinical trials, a COVID-19 vaccine for children will still take some time to develop. That being said, clinical trials are currently underway with results expected from Pfizer and Moderna in early to mid-summer 2021.

Are the current vaccines effective against the existing – and any new – variants of the virus?

Although there's no evidence people immunized with either the Pfizer or Moderna vaccine have less protection against the variants, both companies are looking at ways to account for evolving mutations – particularly the B.1.351 variant first detected in South Africa, which carries a mutation that helps it elude the body's immune response to infection. Other variants are also causing concern, as their mutations appear to make them more transmissible, so they spread faster, and may cause more severe disease. While the J&J vaccine efficacy (discussed in the next question) is lower compared to Pfizer or Moderna’s vaccine, it has demonstrated substantial effectiveness against the variants. Pfizer has begun to test whether any protection is gained against the new variants through a third dose of the vaccine.  Moderna has been updating its vaccine and has recently submitted and shipping variant-specific vaccines as part of a “booster.”

How many other strains of COVID, other than those currently known, do you believe are present and will eventually make their way to the states if they have not already?

There are quite a variety of COVID-19 variants that have been identified. Some below, are frequently known, and others are seemingly popping up:

  • 501Y.v1 aka B.1.1.7, first identified in the United Kingdom (UK),
  • 501Y.V2 aka B1.351, first identified in South Africa,
  • 501Y.V3 (P.1) and P.2, both first identified and spreading in Brazil,

In the United States, there are multiple variants:

  • L452R – first identified in California
  • B.1.427/B.1428, also first identified in California
  • B.1.526 – first identified in New York

Unfortunately, we do not know how many actual variants are currently spreading; nor will we know the full extent of variants. Due to the “make-up” of the variants (they all vary from the original), some are thought to be more transmissible (perhaps less deadly, but easier to spread) while others may have evolved to become more harmful. At this time, there is still a lot more research that is needed into them. Thus, it is important to still maintain social distancing, mask-wearing, hand-washing, and other preventive practices.

Is the vaccine safe for those with existing medical conditions or who are taking chronic/maintenance medicine (e.g., synthroid, cholesterol medicines, warfarin and other blood thinners, etc.)?

While the vaccines can be safe for many medical conditions, it is advised that you let the vaccination provider know of all your medical conditions and medication. A pre-vaccination checklist from the CDC also includes questions addressing some key conditions and medications. While it states that a “yes” answer will not necessarily preclude vaccination, more information may be needed to determine if there is any reason the person should not receive the vaccine without further medical assessment.

Will the COVID-19 shot be annual or a one-time event?

It is not yet fully known how long immunity will last with the current vaccines; however,  experts currently expect that COVID-19 vaccinations may become an annual occurrence (similar to the flu vaccine), rather than a one-time event. As more variants arise, vaccines are also being updated to ensure their ongoing effectiveness.

Based on vaccine deployment, when will the US achieve “herd immunity” for a “return to normalcy”? Once we get our highest risk population vaccinated, how big of a concern is COVID-19?

Population (or “herd”) immunity is achieved when a high percentage of a population is vaccinated or had the disease so becomes immune. A March 2021 study  found that, in most regions, herd immunity is far from being reached. Ideally, herd immunity will be achieved through vaccinationso, we can protect the population without everyone having to get sick. It is currently believed that population immunity will be achieved for COVID-19 when 75% to 85% of a population are vaccinated.

Because COVID-19 can have severe effects, including hospitalization and death, for people who were not previously considered to be at high risk, COVID-19 will continue to be a concern until a high percentage are vaccinated. Even at that point, however, COVID will not go away, and may become endemic like influenza with regular vaccinations needed.

Would you expect that it will be safe to hold a large gathering outdoors by mid summer? If so, what safety protocols should be followed?

This will really depend on the course of the next few months. However, as of Monday March 08, 2021, the CDC has announced that individuals who have been fully vaccinated (full vaccination being someone who has received the full course of vaccines – either one shot of a one-shot vaccine or both shots of a two-shot vaccine – and has waited two weeks), are able to meet indoors, in small numbers,  without a mask.  The risk of outdoor interactions is lower because of improved ventilation.