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?
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?
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.