COVID-19 Vaccines Are Coming. Here’s What to Expect

7 minute read

Vaccines normally take decades to develop and test, but two COVID-19 shots, from Moderna and Pfizer (in partnership with BioNTech), have gone from nonexistent to about 95% effectiveness in 10 months. Public-health officials and governments now have the dual challenge of convincing the public that the vaccines are both safe and scientifically sound, as well as figuring out how to distribute billions of doses. Here’s what we know so far about how that’s going.

When can I get vaccinated?

That depends.

Manufacturers have already begun producing vaccines, betting that they will be effective, so they can be ready to ship if the FDA authorizes them, possibly as soon as December. Still, doses will be limited this year and will be reserved for those at highest risk of infection, such as health care workers as well as those with essential jobs, like first responders and law-enforcement personnel. As vaccine manufacturers fire up production, more people, including those with chronic health conditions, and the elderly, will be able to get immunized. Dr. Anthony Fauci, director of the National Institute of Allergy and Infectious Diseases, says it may not be until spring that most Americans can start to get vaccinated.

Who approves the vaccines?

The Food and Drug Administration must approve any vaccine. But most COVID-19 vaccine makers won’t initially apply for normal approval, which typically requires six or more months of follow-up study. Instead, they will likely ask for emergency-use authorization (EUA), which makes it possible to release new drugs and vaccines during a health emergency. For an EUA, the FDA has said companies should monitor trial participants for two months to make sure the vaccines are safe and don’t lead to serious side effects. All of the testing and other requirements for evaluating safety and effectiveness remain the same for an EUA as for full approval. Many vaccine makers plan to apply for full approval of their shots once they accumulate the appropriate amount of follow-up data.

Were shortcuts taken to develop these vaccines?

According to leading public-health experts and the vaccine makers, the same rigorous scientific process that goes into developing any vaccine was used to create the COVID-19 shots. But in some cases, new technology like the mRNA-based technique used by Moderna and Pfizer—the first two companies to finish human testing—have sped up the development process. The mRNA method doesn’t require researchers to grow or manipulate SARS-CoV-2, the virus responsible for COVID-19; all they need is its genetic sequence, which Chinese scientists released in January. The technology is both fast and flexible, and allowed vaccine makers to develop and start testing their vaccines in a matter of months.

If I get vaccinated, does that mean that I can’t get infected?

Not necessarily.

But it means you are less likely to get sick. When Pfizer announced that its vaccine was more than 95% effective and Moderna said its shot was 94.5% effective, that was how well they kept people from getting sick. In the studies, people were randomly assigned to get the vaccine or a placebo. If anyone in either group felt symptoms of COVID-19 (including fever, cough, headache and difficulty breathing), they reported it to the researchers, who then decided whether to test for COVID-19. So the studies did not test everyone to see how many people in the vaccinated group got infected compared with the placebo group. Instead, the scientists took those participants who tested positive for COVID-19 and compared how many in the vaccinated group went on to develop disease and how many in the placebo group did. The companies will continue to test people in the studies for antibodies to the COVID-19 virus, which would include people who did not show any symptoms of their infection, so they can get a better sense of whether or not the vaccines protect against not only getting sick but also against infection.

Are all the vaccines made the same way?


The various companies are relying on different technologies. Moderna and Pfizer use the mRNA technology based on the pandemic virus’s genetic code. The AstraZeneca and University of Oxford team, as well as Johnson & Johnson/Janssen, are relying on different inactivated cold viruses loaded with COVID-19 viral genes that can produce viral proteins to activate the immune system, while both Novavax and the Sanofi/GlaxoSmithKline partnership are producing and then introducing proteins from the virus itself to trigger an immune response. All are close to completing testing of their shots.

Where can I get vaccinated?

In the first few months after the initial doses are shipped, there will likely be a limited number of ­providers—mostly in public-health clinics and major hospitals. But the federal government has authorized pharmacists to administer COVID-19 vaccines, so eventually retail pharmacies, community health centers and other locations will be offering COVID-19 shots.

Can I choose which vaccine I get?

Probably not.

State health departments will likely be coordinating the ordering and distribution of doses, and they won’t know which vaccines they will receive. Some health departments may request certain vaccines depending, for example, on factors such as whether some of their vaccine facilities have the proper storage equipment like the ultra-cold freezers needed for Pfizer’s vaccine, or perhaps whether the shots show any differences in effectiveness among people of different ages, ethnicities or health conditions. So far, the Moderna and Pfizer vaccines don’t show such distinctions, so they will likely be shipped out based on proposals that state health departments have submitted for how many doses they will need. Although Pfizer’s vaccine needs to be stored at –70°C, the company plans to ship its doses in thermal packaging that can maintain that temperature for up to 15 days, as long as users replenish the dry ice included in the packaging.

Why do I need two doses of vaccine?

All of the COVID-19 vaccines being tested, with the exception of Johnson & Johnson/Janssen’s, require two doses. That’s because researchers found that while the body launches an immune response after the first dose, boosting that initial exposure to the virus magnifies that defense significantly. If a person hasn’t been infected by the COVID-19 virus, it takes a little longer to prime the pump of their immune system against it.

Will I have to pay for a COVID-19 vaccine?

Vaccines supported by U.S. taxpayer dollars under the Operation Warp Speed ­program—which includes those from AstraZeneca, Johnson & Johnson/Janssen, Moderna, Pfizer/BioNTech, Sanofi/GlaxoSmithKline and others—should be free for all Americans, although the details of the purchasing contracts are still unclear. Some health facilities may also charge an administration fee for giving the vaccine, which people will have to pay out of pocket.

Will I still have to wear a mask after I get vaccinated?


Studies so far show only that the vaccines can protect against getting sick with the disease, and may not prevent being infected with the virus. So it’s important to still follow all the public-health measures that throw up an invisible wall against the coronavirus. Even if you’re immunized, you can still get infected with the virus and therefore pass it on to others. That’s why even as more and more people get vaccinated, health officials will continue to ask you to wear a mask in public, practice social distancing and avoid large indoor gatherings. Those basic behaviors will remain critical in keeping the virus from finding new hosts.

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